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83d290c5 | 1 | # SPDX-License-Identifier: GPL-2.0+ |
c609719b | 2 | # |
eca3aeb3 | 3 | # (C) Copyright 2000 - 2013 |
c609719b | 4 | # Wolfgang Denk, DENX Software Engineering, wd@denx.de. |
c609719b WD |
5 | |
6 | Summary: | |
7 | ======== | |
8 | ||
24ee89b9 | 9 | This directory contains the source code for U-Boot, a boot loader for |
e86e5a07 WD |
10 | Embedded boards based on PowerPC, ARM, MIPS and several other |
11 | processors, which can be installed in a boot ROM and used to | |
12 | initialize and test the hardware or to download and run application | |
13 | code. | |
c609719b WD |
14 | |
15 | The development of U-Boot is closely related to Linux: some parts of | |
24ee89b9 WD |
16 | the source code originate in the Linux source tree, we have some |
17 | header files in common, and special provision has been made to | |
c609719b WD |
18 | support booting of Linux images. |
19 | ||
20 | Some attention has been paid to make this software easily | |
21 | configurable and extendable. For instance, all monitor commands are | |
22 | implemented with the same call interface, so that it's very easy to | |
23 | add new commands. Also, instead of permanently adding rarely used | |
24 | code (for instance hardware test utilities) to the monitor, you can | |
25 | load and run it dynamically. | |
26 | ||
27 | ||
28 | Status: | |
29 | ======= | |
30 | ||
31 | In general, all boards for which a configuration option exists in the | |
24ee89b9 | 32 | Makefile have been tested to some extent and can be considered |
c609719b WD |
33 | "working". In fact, many of them are used in production systems. |
34 | ||
7207b366 RD |
35 | In case of problems see the CHANGELOG file to find out who contributed |
36 | the specific port. In addition, there are various MAINTAINERS files | |
37 | scattered throughout the U-Boot source identifying the people or | |
38 | companies responsible for various boards and subsystems. | |
c609719b | 39 | |
7207b366 RD |
40 | Note: As of August, 2010, there is no longer a CHANGELOG file in the |
41 | actual U-Boot source tree; however, it can be created dynamically | |
42 | from the Git log using: | |
adb9d851 RD |
43 | |
44 | make CHANGELOG | |
45 | ||
c609719b WD |
46 | |
47 | Where to get help: | |
48 | ================== | |
49 | ||
24ee89b9 | 50 | In case you have questions about, problems with or contributions for |
7207b366 | 51 | U-Boot, you should send a message to the U-Boot mailing list at |
0c32565f PT |
52 | <u-boot@lists.denx.de>. There is also an archive of previous traffic |
53 | on the mailing list - please search the archive before asking FAQ's. | |
6681bbb5 NH |
54 | Please see https://lists.denx.de/pipermail/u-boot and |
55 | https://marc.info/?l=u-boot | |
c609719b | 56 | |
218ca724 WD |
57 | Where to get source code: |
58 | ========================= | |
59 | ||
7207b366 | 60 | The U-Boot source code is maintained in the Git repository at |
a3bbd0b9 HS |
61 | https://source.denx.de/u-boot/u-boot.git ; you can browse it online at |
62 | https://source.denx.de/u-boot/u-boot | |
218ca724 | 63 | |
c4bd51e2 | 64 | The "Tags" links on this page allow you to download tarballs of |
11ccc33f | 65 | any version you might be interested in. Official releases are also |
c4bd51e2 NH |
66 | available from the DENX file server through HTTPS or FTP. |
67 | https://ftp.denx.de/pub/u-boot/ | |
68 | ftp://ftp.denx.de/pub/u-boot/ | |
218ca724 WD |
69 | |
70 | ||
c609719b WD |
71 | Where we come from: |
72 | =================== | |
73 | ||
74 | - start from 8xxrom sources | |
047f6ec0 | 75 | - create PPCBoot project (https://sourceforge.net/projects/ppcboot) |
c609719b WD |
76 | - clean up code |
77 | - make it easier to add custom boards | |
78 | - make it possible to add other [PowerPC] CPUs | |
79 | - extend functions, especially: | |
80 | * Provide extended interface to Linux boot loader | |
81 | * S-Record download | |
82 | * network boot | |
9e5616de | 83 | * ATA disk / SCSI ... boot |
047f6ec0 | 84 | - create ARMBoot project (https://sourceforge.net/projects/armboot) |
c609719b | 85 | - add other CPU families (starting with ARM) |
047f6ec0 NH |
86 | - create U-Boot project (https://sourceforge.net/projects/u-boot) |
87 | - current project page: see https://www.denx.de/wiki/U-Boot | |
24ee89b9 WD |
88 | |
89 | ||
90 | Names and Spelling: | |
91 | =================== | |
92 | ||
93 | The "official" name of this project is "Das U-Boot". The spelling | |
94 | "U-Boot" shall be used in all written text (documentation, comments | |
95 | in source files etc.). Example: | |
96 | ||
97 | This is the README file for the U-Boot project. | |
98 | ||
99 | File names etc. shall be based on the string "u-boot". Examples: | |
100 | ||
101 | include/asm-ppc/u-boot.h | |
102 | ||
103 | #include <asm/u-boot.h> | |
104 | ||
105 | Variable names, preprocessor constants etc. shall be either based on | |
106 | the string "u_boot" or on "U_BOOT". Example: | |
107 | ||
108 | U_BOOT_VERSION u_boot_logo | |
109 | IH_OS_U_BOOT u_boot_hush_start | |
c609719b WD |
110 | |
111 | ||
93f19cc0 WD |
112 | Versioning: |
113 | =========== | |
114 | ||
360d883a TW |
115 | Starting with the release in October 2008, the names of the releases |
116 | were changed from numerical release numbers without deeper meaning | |
117 | into a time stamp based numbering. Regular releases are identified by | |
118 | names consisting of the calendar year and month of the release date. | |
119 | Additional fields (if present) indicate release candidates or bug fix | |
120 | releases in "stable" maintenance trees. | |
121 | ||
122 | Examples: | |
c0f40859 | 123 | U-Boot v2009.11 - Release November 2009 |
360d883a | 124 | U-Boot v2009.11.1 - Release 1 in version November 2009 stable tree |
0de21ecb | 125 | U-Boot v2010.09-rc1 - Release candidate 1 for September 2010 release |
93f19cc0 WD |
126 | |
127 | ||
c609719b WD |
128 | Directory Hierarchy: |
129 | ==================== | |
130 | ||
6e73ed00 | 131 | /arch Architecture-specific files |
6eae68e4 | 132 | /arc Files generic to ARC architecture |
8d321b81 | 133 | /arm Files generic to ARM architecture |
8d321b81 | 134 | /m68k Files generic to m68k architecture |
8d321b81 | 135 | /microblaze Files generic to microblaze architecture |
8d321b81 | 136 | /mips Files generic to MIPS architecture |
8d321b81 | 137 | /nios2 Files generic to Altera NIOS2 architecture |
a47a12be | 138 | /powerpc Files generic to PowerPC architecture |
3fafced7 | 139 | /riscv Files generic to RISC-V architecture |
7207b366 | 140 | /sandbox Files generic to HW-independent "sandbox" |
8d321b81 | 141 | /sh Files generic to SH architecture |
33c7731b | 142 | /x86 Files generic to x86 architecture |
e4eb313a | 143 | /xtensa Files generic to Xtensa architecture |
6e73ed00 SG |
144 | /api Machine/arch-independent API for external apps |
145 | /board Board-dependent files | |
19a91f24 | 146 | /boot Support for images and booting |
740f7e5c | 147 | /cmd U-Boot commands functions |
6e73ed00 | 148 | /common Misc architecture-independent functions |
7207b366 | 149 | /configs Board default configuration files |
8d321b81 | 150 | /disk Code for disk drive partition handling |
6e73ed00 SG |
151 | /doc Documentation (a mix of ReST and READMEs) |
152 | /drivers Device drivers | |
153 | /dts Makefile for building internal U-Boot fdt. | |
154 | /env Environment support | |
8d321b81 PT |
155 | /examples Example code for standalone applications, etc. |
156 | /fs Filesystem code (cramfs, ext2, jffs2, etc.) | |
157 | /include Header Files | |
7207b366 RD |
158 | /lib Library routines generic to all architectures |
159 | /Licenses Various license files | |
8d321b81 PT |
160 | /net Networking code |
161 | /post Power On Self Test | |
7207b366 RD |
162 | /scripts Various build scripts and Makefiles |
163 | /test Various unit test files | |
6e73ed00 | 164 | /tools Tools to build and sign FIT images, etc. |
c609719b | 165 | |
c609719b WD |
166 | Software Configuration: |
167 | ======================= | |
168 | ||
c609719b WD |
169 | Selection of Processor Architecture and Board Type: |
170 | --------------------------------------------------- | |
171 | ||
172 | For all supported boards there are ready-to-use default | |
ab584d67 | 173 | configurations available; just type "make <board_name>_defconfig". |
c609719b WD |
174 | |
175 | Example: For a TQM823L module type: | |
176 | ||
177 | cd u-boot | |
ab584d67 | 178 | make TQM823L_defconfig |
c609719b | 179 | |
7207b366 RD |
180 | Note: If you're looking for the default configuration file for a board |
181 | you're sure used to be there but is now missing, check the file | |
182 | doc/README.scrapyard for a list of no longer supported boards. | |
c609719b | 183 | |
75b3c3aa SG |
184 | Sandbox Environment: |
185 | -------------------- | |
186 | ||
187 | U-Boot can be built natively to run on a Linux host using the 'sandbox' | |
188 | board. This allows feature development which is not board- or architecture- | |
189 | specific to be undertaken on a native platform. The sandbox is also used to | |
190 | run some of U-Boot's tests. | |
191 | ||
bbb140ed | 192 | See doc/arch/sandbox.rst for more details. |
75b3c3aa SG |
193 | |
194 | ||
db910353 SG |
195 | Board Initialisation Flow: |
196 | -------------------------- | |
197 | ||
198 | This is the intended start-up flow for boards. This should apply for both | |
7207b366 RD |
199 | SPL and U-Boot proper (i.e. they both follow the same rules). |
200 | ||
201 | Note: "SPL" stands for "Secondary Program Loader," which is explained in | |
202 | more detail later in this file. | |
203 | ||
204 | At present, SPL mostly uses a separate code path, but the function names | |
205 | and roles of each function are the same. Some boards or architectures | |
206 | may not conform to this. At least most ARM boards which use | |
207 | CONFIG_SPL_FRAMEWORK conform to this. | |
208 | ||
209 | Execution typically starts with an architecture-specific (and possibly | |
210 | CPU-specific) start.S file, such as: | |
211 | ||
212 | - arch/arm/cpu/armv7/start.S | |
213 | - arch/powerpc/cpu/mpc83xx/start.S | |
214 | - arch/mips/cpu/start.S | |
db910353 | 215 | |
7207b366 RD |
216 | and so on. From there, three functions are called; the purpose and |
217 | limitations of each of these functions are described below. | |
db910353 SG |
218 | |
219 | lowlevel_init(): | |
220 | - purpose: essential init to permit execution to reach board_init_f() | |
221 | - no global_data or BSS | |
222 | - there is no stack (ARMv7 may have one but it will soon be removed) | |
223 | - must not set up SDRAM or use console | |
224 | - must only do the bare minimum to allow execution to continue to | |
225 | board_init_f() | |
226 | - this is almost never needed | |
227 | - return normally from this function | |
228 | ||
229 | board_init_f(): | |
230 | - purpose: set up the machine ready for running board_init_r(): | |
231 | i.e. SDRAM and serial UART | |
232 | - global_data is available | |
233 | - stack is in SRAM | |
234 | - BSS is not available, so you cannot use global/static variables, | |
235 | only stack variables and global_data | |
236 | ||
237 | Non-SPL-specific notes: | |
238 | - dram_init() is called to set up DRAM. If already done in SPL this | |
239 | can do nothing | |
240 | ||
241 | SPL-specific notes: | |
242 | - you can override the entire board_init_f() function with your own | |
243 | version as needed. | |
244 | - preloader_console_init() can be called here in extremis | |
245 | - should set up SDRAM, and anything needed to make the UART work | |
499696e4 | 246 | - there is no need to clear BSS, it will be done by crt0.S |
1425465a AD |
247 | - for specific scenarios on certain architectures an early BSS *can* |
248 | be made available (via CONFIG_SPL_EARLY_BSS by moving the clearing | |
249 | of BSS prior to entering board_init_f()) but doing so is discouraged. | |
250 | Instead it is strongly recommended to architect any code changes | |
251 | or additions such to not depend on the availability of BSS during | |
252 | board_init_f() as indicated in other sections of this README to | |
253 | maintain compatibility and consistency across the entire code base. | |
db910353 SG |
254 | - must return normally from this function (don't call board_init_r() |
255 | directly) | |
256 | ||
257 | Here the BSS is cleared. For SPL, if CONFIG_SPL_STACK_R is defined, then at | |
258 | this point the stack and global_data are relocated to below | |
259 | CONFIG_SPL_STACK_R_ADDR. For non-SPL, U-Boot is relocated to run at the top of | |
260 | memory. | |
261 | ||
262 | board_init_r(): | |
263 | - purpose: main execution, common code | |
264 | - global_data is available | |
265 | - SDRAM is available | |
266 | - BSS is available, all static/global variables can be used | |
267 | - execution eventually continues to main_loop() | |
268 | ||
269 | Non-SPL-specific notes: | |
270 | - U-Boot is relocated to the top of memory and is now running from | |
271 | there. | |
272 | ||
273 | SPL-specific notes: | |
274 | - stack is optionally in SDRAM, if CONFIG_SPL_STACK_R is defined and | |
63b2316c AK |
275 | CONFIG_SYS_FSL_HAS_CCI400 |
276 | ||
277 | Defined For SoC that has cache coherent interconnect | |
278 | CCN-400 | |
7f6c2cbc | 279 | |
c055cee1 AK |
280 | CONFIG_SYS_FSL_HAS_CCN504 |
281 | ||
282 | Defined for SoC that has cache coherent interconnect CCN-504 | |
283 | ||
c609719b WD |
284 | The following options need to be configured: |
285 | ||
2628114e KP |
286 | - CPU Type: Define exactly one, e.g. CONFIG_MPC85XX. |
287 | ||
288 | - Board Type: Define exactly one, e.g. CONFIG_MPC8540ADS. | |
6ccec449 | 289 | |
66412c63 | 290 | - 85xx CPU Options: |
ffd06e02 YS |
291 | CONFIG_SYS_PPC64 |
292 | ||
293 | Specifies that the core is a 64-bit PowerPC implementation (implements | |
294 | the "64" category of the Power ISA). This is necessary for ePAPR | |
295 | compliance, among other possible reasons. | |
296 | ||
33eee330 SW |
297 | CONFIG_SYS_FSL_ERRATUM_A004510 |
298 | ||
299 | Enables a workaround for erratum A004510. If set, | |
300 | then CONFIG_SYS_FSL_ERRATUM_A004510_SVR_REV and | |
301 | CONFIG_SYS_FSL_CORENET_SNOOPVEC_COREONLY must be set. | |
302 | ||
303 | CONFIG_SYS_FSL_ERRATUM_A004510_SVR_REV | |
304 | CONFIG_SYS_FSL_ERRATUM_A004510_SVR_REV2 (optional) | |
305 | ||
306 | Defines one or two SoC revisions (low 8 bits of SVR) | |
307 | for which the A004510 workaround should be applied. | |
308 | ||
309 | The rest of SVR is either not relevant to the decision | |
310 | of whether the erratum is present (e.g. p2040 versus | |
311 | p2041) or is implied by the build target, which controls | |
312 | whether CONFIG_SYS_FSL_ERRATUM_A004510 is set. | |
313 | ||
314 | See Freescale App Note 4493 for more information about | |
315 | this erratum. | |
316 | ||
317 | CONFIG_SYS_FSL_CORENET_SNOOPVEC_COREONLY | |
318 | ||
319 | This is the value to write into CCSR offset 0x18600 | |
320 | according to the A004510 workaround. | |
321 | ||
b135991a PJ |
322 | CONFIG_SYS_FSL_SINGLE_SOURCE_CLK |
323 | Single Source Clock is clocking mode present in some of FSL SoC's. | |
324 | In this mode, a single differential clock is used to supply | |
325 | clocks to the sysclock, ddrclock and usbclock. | |
326 | ||
6cb461b4 | 327 | - Generic CPU options: |
6cb461b4 | 328 | |
5614e71b YS |
329 | CONFIG_SYS_FSL_DDR |
330 | Freescale DDR driver in use. This type of DDR controller is | |
1c58857a | 331 | found in mpc83xx, mpc85xx as well as some ARM core SoCs. |
5614e71b YS |
332 | |
333 | CONFIG_SYS_FSL_DDR_ADDR | |
334 | Freescale DDR memory-mapped register base. | |
335 | ||
1c40707e PK |
336 | CONFIG_SYS_FSL_IFC_CLK_DIV |
337 | Defines divider of platform clock(clock input to IFC controller). | |
338 | ||
add63f94 PK |
339 | CONFIG_SYS_FSL_LBC_CLK_DIV |
340 | Defines divider of platform clock(clock input to eLBC controller). | |
341 | ||
6b9e309a YS |
342 | CONFIG_SYS_FSL_DDR_SDRAM_BASE_PHY |
343 | Physical address from the view of DDR controllers. It is the | |
344 | same as CONFIG_SYS_DDR_SDRAM_BASE for all Power SoCs. But | |
345 | it could be different for ARM SoCs. | |
346 | ||
92bbd64e | 347 | - MIPS CPU options: |
92bbd64e DS |
348 | CONFIG_XWAY_SWAP_BYTES |
349 | ||
350 | Enable compilation of tools/xway-swap-bytes needed for Lantiq | |
351 | XWAY SoCs for booting from NOR flash. The U-Boot image needs to | |
352 | be swapped if a flash programmer is used. | |
353 | ||
b67d8816 CR |
354 | - ARM options: |
355 | CONFIG_SYS_EXCEPTION_VECTORS_HIGH | |
356 | ||
357 | Select high exception vectors of the ARM core, e.g., do not | |
358 | clear the V bit of the c1 register of CP15. | |
359 | ||
207774b2 YS |
360 | COUNTER_FREQUENCY |
361 | Generic timer clock source frequency. | |
362 | ||
363 | COUNTER_FREQUENCY_REAL | |
364 | Generic timer clock source frequency if the real clock is | |
365 | different from COUNTER_FREQUENCY, and can only be determined | |
366 | at run time. | |
367 | ||
73c38934 SW |
368 | - Tegra SoC options: |
369 | CONFIG_TEGRA_SUPPORT_NON_SECURE | |
370 | ||
371 | Support executing U-Boot in non-secure (NS) mode. Certain | |
372 | impossible actions will be skipped if the CPU is in NS mode, | |
373 | such as ARM architectural timer initialization. | |
374 | ||
5da627a4 | 375 | - Linux Kernel Interface: |
5da627a4 WD |
376 | CONFIG_MEMSIZE_IN_BYTES [relevant for MIPS only] |
377 | ||
b445bbb4 | 378 | When transferring memsize parameter to Linux, some versions |
5da627a4 WD |
379 | expect it to be in bytes, others in MB. |
380 | Define CONFIG_MEMSIZE_IN_BYTES to make it in bytes. | |
381 | ||
fec6d9ee | 382 | CONFIG_OF_LIBFDT |
f57f70aa WD |
383 | |
384 | New kernel versions are expecting firmware settings to be | |
213bf8c8 GVB |
385 | passed using flattened device trees (based on open firmware |
386 | concepts). | |
387 | ||
388 | CONFIG_OF_LIBFDT | |
389 | * New libfdt-based support | |
390 | * Adds the "fdt" command | |
3bb342fc | 391 | * The bootm command automatically updates the fdt |
213bf8c8 | 392 | |
f57f70aa WD |
393 | OF_TBCLK - The timebase frequency. |
394 | ||
11ccc33f MZ |
395 | boards with QUICC Engines require OF_QE to set UCC MAC |
396 | addresses | |
3bb342fc | 397 | |
3887c3fb HS |
398 | CONFIG_OF_IDE_FIXUP |
399 | ||
400 | U-Boot can detect if an IDE device is present or not. | |
401 | If not, and this new config option is activated, U-Boot | |
402 | removes the ATA node from the DTS before booting Linux, | |
403 | so the Linux IDE driver does not probe the device and | |
404 | crash. This is needed for buggy hardware (uc101) where | |
405 | no pull down resistor is connected to the signal IDE5V_DD7. | |
406 | ||
0b2f4eca NG |
407 | - vxWorks boot parameters: |
408 | ||
409 | bootvx constructs a valid bootline using the following | |
9e98b7e3 BM |
410 | environments variables: bootdev, bootfile, ipaddr, netmask, |
411 | serverip, gatewayip, hostname, othbootargs. | |
0b2f4eca NG |
412 | It loads the vxWorks image pointed bootfile. |
413 | ||
81a05d9b | 414 | Note: If a "bootargs" environment is defined, it will override |
0b2f4eca NG |
415 | the defaults discussed just above. |
416 | ||
93bc2193 A |
417 | - Cache Configuration for ARM: |
418 | CONFIG_SYS_L2_PL310 - Enable support for ARM PL310 L2 cache | |
419 | controller | |
420 | CONFIG_SYS_PL310_BASE - Physical base address of PL310 | |
421 | controller register space | |
422 | ||
6705d81e | 423 | - Serial Ports: |
6705d81e WD |
424 | CONFIG_PL011_CLOCK |
425 | ||
426 | If you have Amba PrimeCell PL011 UARTs, set this variable to | |
427 | the clock speed of the UARTs. | |
428 | ||
429 | CONFIG_PL01x_PORTS | |
430 | ||
431 | If you have Amba PrimeCell PL010 or PL011 UARTs on your board, | |
432 | define this to a list of base addresses for each (supported) | |
433 | port. See e.g. include/configs/versatile.h | |
434 | ||
d57dee57 KM |
435 | CONFIG_SERIAL_HW_FLOW_CONTROL |
436 | ||
437 | Define this variable to enable hw flow control in serial driver. | |
438 | Current user of this option is drivers/serial/nsl16550.c driver | |
6705d81e | 439 | |
c609719b WD |
440 | - Serial Download Echo Mode: |
441 | CONFIG_LOADS_ECHO | |
442 | If defined to 1, all characters received during a | |
443 | serial download (using the "loads" command) are | |
444 | echoed back. This might be needed by some terminal | |
445 | emulations (like "cu"), but may as well just take | |
446 | time on others. This setting #define's the initial | |
447 | value of the "loads_echo" environment variable. | |
448 | ||
302a6487 SG |
449 | - Removal of commands |
450 | If no commands are needed to boot, you can disable | |
451 | CONFIG_CMDLINE to remove them. In this case, the command line | |
452 | will not be available, and when U-Boot wants to execute the | |
453 | boot command (on start-up) it will call board_run_command() | |
454 | instead. This can reduce image size significantly for very | |
455 | simple boot procedures. | |
456 | ||
a5ecbe62 WD |
457 | - Regular expression support: |
458 | CONFIG_REGEX | |
93e14596 WD |
459 | If this variable is defined, U-Boot is linked against |
460 | the SLRE (Super Light Regular Expression) library, | |
461 | which adds regex support to some commands, as for | |
462 | example "env grep" and "setexpr". | |
a5ecbe62 | 463 | |
c609719b | 464 | - Watchdog: |
933ada56 RV |
465 | CONFIG_SYS_WATCHDOG_FREQ |
466 | Some platforms automatically call WATCHDOG_RESET() | |
467 | from the timer interrupt handler every | |
468 | CONFIG_SYS_WATCHDOG_FREQ interrupts. If not set by the | |
469 | board configuration file, a default of CONFIG_SYS_HZ/2 | |
470 | (i.e. 500) is used. Setting CONFIG_SYS_WATCHDOG_FREQ | |
471 | to 0 disables calling WATCHDOG_RESET() from the timer | |
472 | interrupt. | |
473 | ||
c609719b WD |
474 | - Real-Time Clock: |
475 | ||
602ad3b3 | 476 | When CONFIG_CMD_DATE is selected, the type of the RTC |
c609719b WD |
477 | has to be selected, too. Define exactly one of the |
478 | following options: | |
479 | ||
c609719b | 480 | CONFIG_RTC_PCF8563 - use Philips PCF8563 RTC |
4e8b7544 | 481 | CONFIG_RTC_MC13XXX - use MC13783 or MC13892 RTC |
c609719b | 482 | CONFIG_RTC_MC146818 - use MC146818 RTC |
1cb8e980 | 483 | CONFIG_RTC_DS1307 - use Maxim, Inc. DS1307 RTC |
c609719b | 484 | CONFIG_RTC_DS1337 - use Maxim, Inc. DS1337 RTC |
7f70e853 | 485 | CONFIG_RTC_DS1338 - use Maxim, Inc. DS1338 RTC |
412921d2 | 486 | CONFIG_RTC_DS1339 - use Maxim, Inc. DS1339 RTC |
3bac3513 | 487 | CONFIG_RTC_DS164x - use Dallas DS164x RTC |
9536dfcc | 488 | CONFIG_RTC_ISL1208 - use Intersil ISL1208 RTC |
4c0d4c3b | 489 | CONFIG_RTC_MAX6900 - use Maxim, Inc. MAX6900 RTC |
2bd3cab3 | 490 | CONFIG_RTC_DS1337_NOOSC - Turn off the OSC output for DS1337 |
71d19f30 HS |
491 | CONFIG_SYS_RV3029_TCR - enable trickle charger on |
492 | RV3029 RTC. | |
c609719b | 493 | |
b37c7e5e WD |
494 | Note that if the RTC uses I2C, then the I2C interface |
495 | must also be configured. See I2C Support, below. | |
496 | ||
e92739d3 PT |
497 | - GPIO Support: |
498 | CONFIG_PCA953X - use NXP's PCA953X series I2C GPIO | |
e92739d3 | 499 | |
5dec49ca CP |
500 | The CONFIG_SYS_I2C_PCA953X_WIDTH option specifies a list of |
501 | chip-ngpio pairs that tell the PCA953X driver the number of | |
502 | pins supported by a particular chip. | |
503 | ||
e92739d3 PT |
504 | Note that if the GPIO device uses I2C, then the I2C interface |
505 | must also be configured. See I2C Support, below. | |
506 | ||
aa53233a SG |
507 | - I/O tracing: |
508 | When CONFIG_IO_TRACE is selected, U-Boot intercepts all I/O | |
509 | accesses and can checksum them or write a list of them out | |
510 | to memory. See the 'iotrace' command for details. This is | |
511 | useful for testing device drivers since it can confirm that | |
512 | the driver behaves the same way before and after a code | |
513 | change. Currently this is supported on sandbox and arm. To | |
514 | add support for your architecture, add '#include <iotrace.h>' | |
515 | to the bottom of arch/<arch>/include/asm/io.h and test. | |
516 | ||
517 | Example output from the 'iotrace stats' command is below. | |
518 | Note that if the trace buffer is exhausted, the checksum will | |
519 | still continue to operate. | |
520 | ||
521 | iotrace is enabled | |
522 | Start: 10000000 (buffer start address) | |
523 | Size: 00010000 (buffer size) | |
524 | Offset: 00000120 (current buffer offset) | |
525 | Output: 10000120 (start + offset) | |
526 | Count: 00000018 (number of trace records) | |
527 | CRC32: 9526fb66 (CRC32 of all trace records) | |
528 | ||
c609719b WD |
529 | - Timestamp Support: |
530 | ||
43d9616c WD |
531 | When CONFIG_TIMESTAMP is selected, the timestamp |
532 | (date and time) of an image is printed by image | |
533 | commands like bootm or iminfo. This option is | |
602ad3b3 | 534 | automatically enabled when you select CONFIG_CMD_DATE . |
c609719b | 535 | |
923c46f9 KP |
536 | - Partition Labels (disklabels) Supported: |
537 | Zero or more of the following: | |
538 | CONFIG_MAC_PARTITION Apple's MacOS partition table. | |
923c46f9 KP |
539 | CONFIG_ISO_PARTITION ISO partition table, used on CDROM etc. |
540 | CONFIG_EFI_PARTITION GPT partition table, common when EFI is the | |
541 | bootloader. Note 2TB partition limit; see | |
542 | disk/part_efi.c | |
c649e3c9 | 543 | CONFIG_SCSI) you must configure support for at |
923c46f9 | 544 | least one non-MTD partition type as well. |
c609719b | 545 | |
c609719b | 546 | - NETWORK Support (PCI): |
ce5207e1 KM |
547 | CONFIG_E1000_SPI |
548 | Utility code for direct access to the SPI bus on Intel 8257x. | |
549 | This does not do anything useful unless you set at least one | |
550 | of CONFIG_CMD_E1000 or CONFIG_E1000_SPI_GENERIC. | |
551 | ||
c609719b WD |
552 | CONFIG_NATSEMI |
553 | Support for National dp83815 chips. | |
554 | ||
555 | CONFIG_NS8382X | |
556 | Support for National dp8382[01] gigabit chips. | |
557 | ||
45219c46 | 558 | - NETWORK Support (other): |
efdd7319 RH |
559 | CONFIG_CALXEDA_XGMAC |
560 | Support for the Calxeda XGMAC device | |
561 | ||
3bb46d23 | 562 | CONFIG_LAN91C96 |
45219c46 WD |
563 | Support for SMSC's LAN91C96 chips. |
564 | ||
45219c46 WD |
565 | CONFIG_LAN91C96_USE_32_BIT |
566 | Define this to enable 32 bit addressing | |
567 | ||
dc02bada HS |
568 | CONFIG_SYS_DAVINCI_EMAC_PHY_COUNT |
569 | Define this if you have more then 3 PHYs. | |
570 | ||
b3dbf4a5 ML |
571 | CONFIG_FTGMAC100 |
572 | Support for Faraday's FTGMAC100 Gigabit SoC Ethernet | |
573 | ||
574 | CONFIG_FTGMAC100_EGIGA | |
575 | Define this to use GE link update with gigabit PHY. | |
576 | Define this if FTGMAC100 is connected to gigabit PHY. | |
577 | If your system has 10/100 PHY only, it might not occur | |
578 | wrong behavior. Because PHY usually return timeout or | |
579 | useless data when polling gigabit status and gigabit | |
580 | control registers. This behavior won't affect the | |
581 | correctnessof 10/100 link speed update. | |
582 | ||
3d0075fa YS |
583 | CONFIG_SH_ETHER |
584 | Support for Renesas on-chip Ethernet controller | |
585 | ||
586 | CONFIG_SH_ETHER_USE_PORT | |
587 | Define the number of ports to be used | |
588 | ||
589 | CONFIG_SH_ETHER_PHY_ADDR | |
590 | Define the ETH PHY's address | |
591 | ||
68260aab YS |
592 | CONFIG_SH_ETHER_CACHE_WRITEBACK |
593 | If this option is set, the driver enables cache flush. | |
594 | ||
5e124724 | 595 | - TPM Support: |
90899cc0 CC |
596 | CONFIG_TPM |
597 | Support TPM devices. | |
598 | ||
0766ad2f CR |
599 | CONFIG_TPM_TIS_INFINEON |
600 | Support for Infineon i2c bus TPM devices. Only one device | |
1b393db5 TWHT |
601 | per system is supported at this time. |
602 | ||
1b393db5 TWHT |
603 | CONFIG_TPM_TIS_I2C_BURST_LIMITATION |
604 | Define the burst count bytes upper limit | |
605 | ||
3aa74088 CR |
606 | CONFIG_TPM_ST33ZP24 |
607 | Support for STMicroelectronics TPM devices. Requires DM_TPM support. | |
608 | ||
609 | CONFIG_TPM_ST33ZP24_I2C | |
610 | Support for STMicroelectronics ST33ZP24 I2C devices. | |
611 | Requires TPM_ST33ZP24 and I2C. | |
612 | ||
b75fdc11 CR |
613 | CONFIG_TPM_ST33ZP24_SPI |
614 | Support for STMicroelectronics ST33ZP24 SPI devices. | |
615 | Requires TPM_ST33ZP24 and SPI. | |
616 | ||
c01939c7 DE |
617 | CONFIG_TPM_ATMEL_TWI |
618 | Support for Atmel TWI TPM device. Requires I2C support. | |
619 | ||
90899cc0 | 620 | CONFIG_TPM_TIS_LPC |
5e124724 VB |
621 | Support for generic parallel port TPM devices. Only one device |
622 | per system is supported at this time. | |
623 | ||
624 | CONFIG_TPM_TIS_BASE_ADDRESS | |
625 | Base address where the generic TPM device is mapped | |
626 | to. Contemporary x86 systems usually map it at | |
627 | 0xfed40000. | |
628 | ||
be6c1529 RP |
629 | CONFIG_TPM |
630 | Define this to enable the TPM support library which provides | |
631 | functional interfaces to some TPM commands. | |
632 | Requires support for a TPM device. | |
633 | ||
634 | CONFIG_TPM_AUTH_SESSIONS | |
635 | Define this to enable authorized functions in the TPM library. | |
636 | Requires CONFIG_TPM and CONFIG_SHA1. | |
637 | ||
c609719b WD |
638 | - USB Support: |
639 | At the moment only the UHCI host controller is | |
064b55cf | 640 | supported (PIP405, MIP405); define |
c609719b WD |
641 | CONFIG_USB_UHCI to enable it. |
642 | define CONFIG_USB_KEYBOARD to enable the USB Keyboard | |
30d56fae | 643 | and define CONFIG_USB_STORAGE to enable the USB |
c609719b WD |
644 | storage devices. |
645 | Note: | |
646 | Supported are USB Keyboards and USB Floppy drives | |
647 | (TEAC FD-05PUB). | |
4d13cbad | 648 | |
6e9e0626 OT |
649 | CONFIG_USB_DWC2_REG_ADDR the physical CPU address of the DWC2 |
650 | HW module registers. | |
651 | ||
16c8d5e7 WD |
652 | - USB Device: |
653 | Define the below if you wish to use the USB console. | |
654 | Once firmware is rebuilt from a serial console issue the | |
655 | command "setenv stdin usbtty; setenv stdout usbtty" and | |
11ccc33f | 656 | attach your USB cable. The Unix command "dmesg" should print |
16c8d5e7 WD |
657 | it has found a new device. The environment variable usbtty |
658 | can be set to gserial or cdc_acm to enable your device to | |
386eda02 | 659 | appear to a USB host as a Linux gserial device or a |
16c8d5e7 WD |
660 | Common Device Class Abstract Control Model serial device. |
661 | If you select usbtty = gserial you should be able to enumerate | |
662 | a Linux host by | |
663 | # modprobe usbserial vendor=0xVendorID product=0xProductID | |
664 | else if using cdc_acm, simply setting the environment | |
665 | variable usbtty to be cdc_acm should suffice. The following | |
666 | might be defined in YourBoardName.h | |
386eda02 | 667 | |
16c8d5e7 WD |
668 | CONFIG_USB_DEVICE |
669 | Define this to build a UDC device | |
670 | ||
671 | CONFIG_USB_TTY | |
672 | Define this to have a tty type of device available to | |
673 | talk to the UDC device | |
386eda02 | 674 | |
f9da0f89 VK |
675 | CONFIG_USBD_HS |
676 | Define this to enable the high speed support for usb | |
677 | device and usbtty. If this feature is enabled, a routine | |
678 | int is_usbd_high_speed(void) | |
679 | also needs to be defined by the driver to dynamically poll | |
680 | whether the enumeration has succeded at high speed or full | |
681 | speed. | |
682 | ||
386eda02 | 683 | If you have a USB-IF assigned VendorID then you may wish to |
16c8d5e7 | 684 | define your own vendor specific values either in BoardName.h |
386eda02 | 685 | or directly in usbd_vendor_info.h. If you don't define |
16c8d5e7 WD |
686 | CONFIG_USBD_MANUFACTURER, CONFIG_USBD_PRODUCT_NAME, |
687 | CONFIG_USBD_VENDORID and CONFIG_USBD_PRODUCTID, then U-Boot | |
688 | should pretend to be a Linux device to it's target host. | |
689 | ||
690 | CONFIG_USBD_MANUFACTURER | |
691 | Define this string as the name of your company for | |
692 | - CONFIG_USBD_MANUFACTURER "my company" | |
386eda02 | 693 | |
16c8d5e7 WD |
694 | CONFIG_USBD_PRODUCT_NAME |
695 | Define this string as the name of your product | |
696 | - CONFIG_USBD_PRODUCT_NAME "acme usb device" | |
697 | ||
698 | CONFIG_USBD_VENDORID | |
699 | Define this as your assigned Vendor ID from the USB | |
700 | Implementors Forum. This *must* be a genuine Vendor ID | |
701 | to avoid polluting the USB namespace. | |
702 | - CONFIG_USBD_VENDORID 0xFFFF | |
386eda02 | 703 | |
16c8d5e7 WD |
704 | CONFIG_USBD_PRODUCTID |
705 | Define this as the unique Product ID | |
706 | for your device | |
707 | - CONFIG_USBD_PRODUCTID 0xFFFF | |
4d13cbad | 708 | |
d70a560f IG |
709 | - ULPI Layer Support: |
710 | The ULPI (UTMI Low Pin (count) Interface) PHYs are supported via | |
711 | the generic ULPI layer. The generic layer accesses the ULPI PHY | |
712 | via the platform viewport, so you need both the genric layer and | |
713 | the viewport enabled. Currently only Chipidea/ARC based | |
714 | viewport is supported. | |
715 | To enable the ULPI layer support, define CONFIG_USB_ULPI and | |
716 | CONFIG_USB_ULPI_VIEWPORT in your board configuration file. | |
6d365ea0 LS |
717 | If your ULPI phy needs a different reference clock than the |
718 | standard 24 MHz then you have to define CONFIG_ULPI_REF_CLK to | |
719 | the appropriate value in Hz. | |
c609719b | 720 | |
71f95118 | 721 | - MMC Support: |
afb35666 YS |
722 | CONFIG_SH_MMCIF |
723 | Support for Renesas on-chip MMCIF controller | |
724 | ||
725 | CONFIG_SH_MMCIF_ADDR | |
726 | Define the base address of MMCIF registers | |
727 | ||
728 | CONFIG_SH_MMCIF_CLK | |
729 | Define the clock frequency for MMCIF | |
730 | ||
b3ba6e94 | 731 | - USB Device Firmware Update (DFU) class support: |
bb4059a5 | 732 | CONFIG_DFU_OVER_USB |
b3ba6e94 TR |
733 | This enables the USB portion of the DFU USB class |
734 | ||
c6631764 PA |
735 | CONFIG_DFU_NAND |
736 | This enables support for exposing NAND devices via DFU. | |
737 | ||
a9479f04 AM |
738 | CONFIG_DFU_RAM |
739 | This enables support for exposing RAM via DFU. | |
740 | Note: DFU spec refer to non-volatile memory usage, but | |
741 | allow usages beyond the scope of spec - here RAM usage, | |
742 | one that would help mostly the developer. | |
743 | ||
e7e75c70 HS |
744 | CONFIG_SYS_DFU_DATA_BUF_SIZE |
745 | Dfu transfer uses a buffer before writing data to the | |
746 | raw storage device. Make the size (in bytes) of this buffer | |
747 | configurable. The size of this buffer is also configurable | |
748 | through the "dfu_bufsiz" environment variable. | |
749 | ||
ea2453d5 PA |
750 | CONFIG_SYS_DFU_MAX_FILE_SIZE |
751 | When updating files rather than the raw storage device, | |
752 | we use a static buffer to copy the file into and then write | |
753 | the buffer once we've been given the whole file. Define | |
754 | this to the maximum filesize (in bytes) for the buffer. | |
755 | Default is 4 MiB if undefined. | |
756 | ||
001a8319 HS |
757 | DFU_DEFAULT_POLL_TIMEOUT |
758 | Poll timeout [ms], is the timeout a device can send to the | |
759 | host. The host must wait for this timeout before sending | |
760 | a subsequent DFU_GET_STATUS request to the device. | |
761 | ||
762 | DFU_MANIFEST_POLL_TIMEOUT | |
763 | Poll timeout [ms], which the device sends to the host when | |
764 | entering dfuMANIFEST state. Host waits this timeout, before | |
765 | sending again an USB request to the device. | |
766 | ||
6705d81e | 767 | - Journaling Flash filesystem support: |
6d0f6bcf JCPV |
768 | CONFIG_SYS_JFFS2_FIRST_SECTOR, |
769 | CONFIG_SYS_JFFS2_FIRST_BANK, CONFIG_SYS_JFFS2_NUM_BANKS | |
6705d81e WD |
770 | Define these for a default partition on a NOR device |
771 | ||
c609719b | 772 | - Keyboard Support: |
39f615ed SG |
773 | See Kconfig help for available keyboard drivers. |
774 | ||
c609719b WD |
775 | - LCD Support: CONFIG_LCD |
776 | ||
777 | Define this to enable LCD support (for output to LCD | |
778 | display); also select one of the supported displays | |
779 | by defining one of these: | |
780 | ||
fd3103bb | 781 | CONFIG_NEC_NL6448AC33: |
c609719b | 782 | |
fd3103bb | 783 | NEC NL6448AC33-18. Active, color, single scan. |
c609719b | 784 | |
fd3103bb | 785 | CONFIG_NEC_NL6448BC20 |
c609719b | 786 | |
fd3103bb WD |
787 | NEC NL6448BC20-08. 6.5", 640x480. |
788 | Active, color, single scan. | |
789 | ||
790 | CONFIG_NEC_NL6448BC33_54 | |
791 | ||
792 | NEC NL6448BC33-54. 10.4", 640x480. | |
c609719b WD |
793 | Active, color, single scan. |
794 | ||
795 | CONFIG_SHARP_16x9 | |
796 | ||
797 | Sharp 320x240. Active, color, single scan. | |
798 | It isn't 16x9, and I am not sure what it is. | |
799 | ||
800 | CONFIG_SHARP_LQ64D341 | |
801 | ||
802 | Sharp LQ64D341 display, 640x480. | |
803 | Active, color, single scan. | |
804 | ||
805 | CONFIG_HLD1045 | |
806 | ||
807 | HLD1045 display, 640x480. | |
808 | Active, color, single scan. | |
809 | ||
810 | CONFIG_OPTREX_BW | |
811 | ||
812 | Optrex CBL50840-2 NF-FW 99 22 M5 | |
813 | or | |
814 | Hitachi LMG6912RPFC-00T | |
815 | or | |
816 | Hitachi SP14Q002 | |
817 | ||
818 | 320x240. Black & white. | |
819 | ||
676d319e SG |
820 | CONFIG_LCD_ALIGNMENT |
821 | ||
b445bbb4 | 822 | Normally the LCD is page-aligned (typically 4KB). If this is |
676d319e SG |
823 | defined then the LCD will be aligned to this value instead. |
824 | For ARM it is sometimes useful to use MMU_SECTION_SIZE | |
825 | here, since it is cheaper to change data cache settings on | |
826 | a per-section basis. | |
827 | ||
828 | ||
604c7d4a HP |
829 | CONFIG_LCD_ROTATION |
830 | ||
831 | Sometimes, for example if the display is mounted in portrait | |
832 | mode or even if it's mounted landscape but rotated by 180degree, | |
833 | we need to rotate our content of the display relative to the | |
834 | framebuffer, so that user can read the messages which are | |
835 | printed out. | |
836 | Once CONFIG_LCD_ROTATION is defined, the lcd_console will be | |
837 | initialized with a given rotation from "vl_rot" out of | |
838 | "vidinfo_t" which is provided by the board specific code. | |
839 | The value for vl_rot is coded as following (matching to | |
840 | fbcon=rotate:<n> linux-kernel commandline): | |
841 | 0 = no rotation respectively 0 degree | |
842 | 1 = 90 degree rotation | |
843 | 2 = 180 degree rotation | |
844 | 3 = 270 degree rotation | |
845 | ||
846 | If CONFIG_LCD_ROTATION is not defined, the console will be | |
847 | initialized with 0degree rotation. | |
848 | ||
17ea1177 | 849 | - MII/PHY support: |
17ea1177 WD |
850 | CONFIG_PHY_CLOCK_FREQ (ppc4xx) |
851 | ||
852 | The clock frequency of the MII bus | |
853 | ||
17ea1177 WD |
854 | CONFIG_PHY_CMD_DELAY (ppc4xx) |
855 | ||
856 | Some PHY like Intel LXT971A need extra delay after | |
857 | command issued before MII status register can be read | |
858 | ||
c609719b WD |
859 | - IP address: |
860 | CONFIG_IPADDR | |
861 | ||
862 | Define a default value for the IP address to use for | |
11ccc33f | 863 | the default Ethernet interface, in case this is not |
c609719b | 864 | determined through e.g. bootp. |
1ebcd654 | 865 | (Environment variable "ipaddr") |
c609719b WD |
866 | |
867 | - Server IP address: | |
868 | CONFIG_SERVERIP | |
869 | ||
11ccc33f | 870 | Defines a default value for the IP address of a TFTP |
c609719b | 871 | server to contact when using the "tftboot" command. |
1ebcd654 | 872 | (Environment variable "serverip") |
c609719b | 873 | |
1ebcd654 WD |
874 | - Gateway IP address: |
875 | CONFIG_GATEWAYIP | |
876 | ||
877 | Defines a default value for the IP address of the | |
878 | default router where packets to other networks are | |
879 | sent to. | |
880 | (Environment variable "gatewayip") | |
881 | ||
882 | - Subnet mask: | |
883 | CONFIG_NETMASK | |
884 | ||
885 | Defines a default value for the subnet mask (or | |
886 | routing prefix) which is used to determine if an IP | |
887 | address belongs to the local subnet or needs to be | |
888 | forwarded through a router. | |
889 | (Environment variable "netmask") | |
890 | ||
c609719b WD |
891 | - BOOTP Recovery Mode: |
892 | CONFIG_BOOTP_RANDOM_DELAY | |
893 | ||
894 | If you have many targets in a network that try to | |
895 | boot using BOOTP, you may want to avoid that all | |
896 | systems send out BOOTP requests at precisely the same | |
897 | moment (which would happen for instance at recovery | |
898 | from a power failure, when all systems will try to | |
899 | boot, thus flooding the BOOTP server. Defining | |
900 | CONFIG_BOOTP_RANDOM_DELAY causes a random delay to be | |
901 | inserted before sending out BOOTP requests. The | |
6c33c785 | 902 | following delays are inserted then: |
c609719b WD |
903 | |
904 | 1st BOOTP request: delay 0 ... 1 sec | |
905 | 2nd BOOTP request: delay 0 ... 2 sec | |
906 | 3rd BOOTP request: delay 0 ... 4 sec | |
907 | 4th and following | |
908 | BOOTP requests: delay 0 ... 8 sec | |
909 | ||
92ac8acc TR |
910 | CONFIG_BOOTP_ID_CACHE_SIZE |
911 | ||
912 | BOOTP packets are uniquely identified using a 32-bit ID. The | |
913 | server will copy the ID from client requests to responses and | |
914 | U-Boot will use this to determine if it is the destination of | |
915 | an incoming response. Some servers will check that addresses | |
916 | aren't in use before handing them out (usually using an ARP | |
917 | ping) and therefore take up to a few hundred milliseconds to | |
918 | respond. Network congestion may also influence the time it | |
919 | takes for a response to make it back to the client. If that | |
920 | time is too long, U-Boot will retransmit requests. In order | |
921 | to allow earlier responses to still be accepted after these | |
922 | retransmissions, U-Boot's BOOTP client keeps a small cache of | |
923 | IDs. The CONFIG_BOOTP_ID_CACHE_SIZE controls the size of this | |
924 | cache. The default is to keep IDs for up to four outstanding | |
925 | requests. Increasing this will allow U-Boot to accept offers | |
926 | from a BOOTP client in networks with unusually high latency. | |
927 | ||
fe389a82 | 928 | - DHCP Advanced Options: |
2c00e099 | 929 | |
d22c338e JH |
930 | - Link-local IP address negotiation: |
931 | Negotiate with other link-local clients on the local network | |
932 | for an address that doesn't require explicit configuration. | |
933 | This is especially useful if a DHCP server cannot be guaranteed | |
934 | to exist in all environments that the device must operate. | |
935 | ||
936 | See doc/README.link-local for more information. | |
937 | ||
24acb83d PK |
938 | - MAC address from environment variables |
939 | ||
940 | FDT_SEQ_MACADDR_FROM_ENV | |
941 | ||
942 | Fix-up device tree with MAC addresses fetched sequentially from | |
943 | environment variables. This config work on assumption that | |
944 | non-usable ethernet node of device-tree are either not present | |
945 | or their status has been marked as "disabled". | |
946 | ||
a3d991bd | 947 | - CDP Options: |
6e592385 | 948 | CONFIG_CDP_DEVICE_ID |
a3d991bd WD |
949 | |
950 | The device id used in CDP trigger frames. | |
951 | ||
952 | CONFIG_CDP_DEVICE_ID_PREFIX | |
953 | ||
954 | A two character string which is prefixed to the MAC address | |
955 | of the device. | |
956 | ||
957 | CONFIG_CDP_PORT_ID | |
958 | ||
959 | A printf format string which contains the ascii name of | |
960 | the port. Normally is set to "eth%d" which sets | |
11ccc33f | 961 | eth0 for the first Ethernet, eth1 for the second etc. |
a3d991bd WD |
962 | |
963 | CONFIG_CDP_CAPABILITIES | |
964 | ||
965 | A 32bit integer which indicates the device capabilities; | |
966 | 0x00000010 for a normal host which does not forwards. | |
967 | ||
968 | CONFIG_CDP_VERSION | |
969 | ||
970 | An ascii string containing the version of the software. | |
971 | ||
972 | CONFIG_CDP_PLATFORM | |
973 | ||
974 | An ascii string containing the name of the platform. | |
975 | ||
976 | CONFIG_CDP_TRIGGER | |
977 | ||
978 | A 32bit integer sent on the trigger. | |
979 | ||
980 | CONFIG_CDP_POWER_CONSUMPTION | |
981 | ||
982 | A 16bit integer containing the power consumption of the | |
983 | device in .1 of milliwatts. | |
984 | ||
985 | CONFIG_CDP_APPLIANCE_VLAN_TYPE | |
986 | ||
987 | A byte containing the id of the VLAN. | |
988 | ||
79267edd | 989 | - Status LED: CONFIG_LED_STATUS |
c609719b WD |
990 | |
991 | Several configurations allow to display the current | |
992 | status using a LED. For instance, the LED will blink | |
993 | fast while running U-Boot code, stop blinking as | |
994 | soon as a reply to a BOOTP request was received, and | |
995 | start blinking slow once the Linux kernel is running | |
996 | (supported by a status LED driver in the Linux | |
79267edd | 997 | kernel). Defining CONFIG_LED_STATUS enables this |
c609719b WD |
998 | feature in U-Boot. |
999 | ||
1df7bbba IG |
1000 | Additional options: |
1001 | ||
79267edd | 1002 | CONFIG_LED_STATUS_GPIO |
1df7bbba IG |
1003 | The status LED can be connected to a GPIO pin. |
1004 | In such cases, the gpio_led driver can be used as a | |
79267edd | 1005 | status LED backend implementation. Define CONFIG_LED_STATUS_GPIO |
1df7bbba IG |
1006 | to include the gpio_led driver in the U-Boot binary. |
1007 | ||
9dfdcdfe IG |
1008 | CONFIG_GPIO_LED_INVERTED_TABLE |
1009 | Some GPIO connected LEDs may have inverted polarity in which | |
1010 | case the GPIO high value corresponds to LED off state and | |
1011 | GPIO low value corresponds to LED on state. | |
1012 | In such cases CONFIG_GPIO_LED_INVERTED_TABLE may be defined | |
1013 | with a list of GPIO LEDs that have inverted polarity. | |
1014 | ||
55dabcc8 | 1015 | - I2C Support: |
3f4978c7 | 1016 | CONFIG_SYS_NUM_I2C_BUSES |
945a18e6 | 1017 | Hold the number of i2c buses you want to use. |
3f4978c7 HS |
1018 | |
1019 | CONFIG_SYS_I2C_DIRECT_BUS | |
1020 | define this, if you don't use i2c muxes on your hardware. | |
1021 | if CONFIG_SYS_I2C_MAX_HOPS is not defined or == 0 you can | |
1022 | omit this define. | |
1023 | ||
1024 | CONFIG_SYS_I2C_MAX_HOPS | |
1025 | define how many muxes are maximal consecutively connected | |
1026 | on one i2c bus. If you not use i2c muxes, omit this | |
1027 | define. | |
1028 | ||
1029 | CONFIG_SYS_I2C_BUSES | |
b445bbb4 | 1030 | hold a list of buses you want to use, only used if |
3f4978c7 HS |
1031 | CONFIG_SYS_I2C_DIRECT_BUS is not defined, for example |
1032 | a board with CONFIG_SYS_I2C_MAX_HOPS = 1 and | |
1033 | CONFIG_SYS_NUM_I2C_BUSES = 9: | |
1034 | ||
1035 | CONFIG_SYS_I2C_BUSES {{0, {I2C_NULL_HOP}}, \ | |
1036 | {0, {{I2C_MUX_PCA9547, 0x70, 1}}}, \ | |
1037 | {0, {{I2C_MUX_PCA9547, 0x70, 2}}}, \ | |
1038 | {0, {{I2C_MUX_PCA9547, 0x70, 3}}}, \ | |
1039 | {0, {{I2C_MUX_PCA9547, 0x70, 4}}}, \ | |
1040 | {0, {{I2C_MUX_PCA9547, 0x70, 5}}}, \ | |
1041 | {1, {I2C_NULL_HOP}}, \ | |
1042 | {1, {{I2C_MUX_PCA9544, 0x72, 1}}}, \ | |
1043 | {1, {{I2C_MUX_PCA9544, 0x72, 2}}}, \ | |
1044 | } | |
1045 | ||
1046 | which defines | |
1047 | bus 0 on adapter 0 without a mux | |
ea818dbb HS |
1048 | bus 1 on adapter 0 with a PCA9547 on address 0x70 port 1 |
1049 | bus 2 on adapter 0 with a PCA9547 on address 0x70 port 2 | |
1050 | bus 3 on adapter 0 with a PCA9547 on address 0x70 port 3 | |
1051 | bus 4 on adapter 0 with a PCA9547 on address 0x70 port 4 | |
1052 | bus 5 on adapter 0 with a PCA9547 on address 0x70 port 5 | |
3f4978c7 | 1053 | bus 6 on adapter 1 without a mux |
ea818dbb HS |
1054 | bus 7 on adapter 1 with a PCA9544 on address 0x72 port 1 |
1055 | bus 8 on adapter 1 with a PCA9544 on address 0x72 port 2 | |
3f4978c7 HS |
1056 | |
1057 | If you do not have i2c muxes on your board, omit this define. | |
1058 | ||
ce3b5d69 | 1059 | - Legacy I2C Support: |
ea818dbb | 1060 | If you use the software i2c interface (CONFIG_SYS_I2C_SOFT) |
b37c7e5e WD |
1061 | then the following macros need to be defined (examples are |
1062 | from include/configs/lwmon.h): | |
c609719b WD |
1063 | |
1064 | I2C_INIT | |
1065 | ||
b37c7e5e | 1066 | (Optional). Any commands necessary to enable the I2C |
43d9616c | 1067 | controller or configure ports. |
c609719b | 1068 | |
ba56f625 | 1069 | eg: #define I2C_INIT (immr->im_cpm.cp_pbdir |= PB_SCL) |
b37c7e5e | 1070 | |
c609719b WD |
1071 | I2C_ACTIVE |
1072 | ||
1073 | The code necessary to make the I2C data line active | |
1074 | (driven). If the data line is open collector, this | |
1075 | define can be null. | |
1076 | ||
b37c7e5e WD |
1077 | eg: #define I2C_ACTIVE (immr->im_cpm.cp_pbdir |= PB_SDA) |
1078 | ||
c609719b WD |
1079 | I2C_TRISTATE |
1080 | ||
1081 | The code necessary to make the I2C data line tri-stated | |
1082 | (inactive). If the data line is open collector, this | |
1083 | define can be null. | |
1084 | ||
b37c7e5e WD |
1085 | eg: #define I2C_TRISTATE (immr->im_cpm.cp_pbdir &= ~PB_SDA) |
1086 | ||
c609719b WD |
1087 | I2C_READ |
1088 | ||
472d5460 YS |
1089 | Code that returns true if the I2C data line is high, |
1090 | false if it is low. | |
c609719b | 1091 | |
b37c7e5e WD |
1092 | eg: #define I2C_READ ((immr->im_cpm.cp_pbdat & PB_SDA) != 0) |
1093 | ||
c609719b WD |
1094 | I2C_SDA(bit) |
1095 | ||
472d5460 YS |
1096 | If <bit> is true, sets the I2C data line high. If it |
1097 | is false, it clears it (low). | |
c609719b | 1098 | |
b37c7e5e | 1099 | eg: #define I2C_SDA(bit) \ |
2535d602 | 1100 | if(bit) immr->im_cpm.cp_pbdat |= PB_SDA; \ |
ba56f625 | 1101 | else immr->im_cpm.cp_pbdat &= ~PB_SDA |
b37c7e5e | 1102 | |
c609719b WD |
1103 | I2C_SCL(bit) |
1104 | ||
472d5460 YS |
1105 | If <bit> is true, sets the I2C clock line high. If it |
1106 | is false, it clears it (low). | |
c609719b | 1107 | |
b37c7e5e | 1108 | eg: #define I2C_SCL(bit) \ |
2535d602 | 1109 | if(bit) immr->im_cpm.cp_pbdat |= PB_SCL; \ |
ba56f625 | 1110 | else immr->im_cpm.cp_pbdat &= ~PB_SCL |
b37c7e5e | 1111 | |
c609719b WD |
1112 | I2C_DELAY |
1113 | ||
1114 | This delay is invoked four times per clock cycle so this | |
1115 | controls the rate of data transfer. The data rate thus | |
b37c7e5e | 1116 | is 1 / (I2C_DELAY * 4). Often defined to be something |
945af8d7 WD |
1117 | like: |
1118 | ||
b37c7e5e | 1119 | #define I2C_DELAY udelay(2) |
c609719b | 1120 | |
793b5726 MF |
1121 | CONFIG_SOFT_I2C_GPIO_SCL / CONFIG_SOFT_I2C_GPIO_SDA |
1122 | ||
1123 | If your arch supports the generic GPIO framework (asm/gpio.h), | |
1124 | then you may alternatively define the two GPIOs that are to be | |
1125 | used as SCL / SDA. Any of the previous I2C_xxx macros will | |
1126 | have GPIO-based defaults assigned to them as appropriate. | |
1127 | ||
1128 | You should define these to the GPIO value as given directly to | |
1129 | the generic GPIO functions. | |
1130 | ||
6d0f6bcf | 1131 | CONFIG_SYS_I2C_INIT_BOARD |
47cd00fa | 1132 | |
8bde7f77 WD |
1133 | When a board is reset during an i2c bus transfer |
1134 | chips might think that the current transfer is still | |
1135 | in progress. On some boards it is possible to access | |
1136 | the i2c SCLK line directly, either by using the | |
1137 | processor pin as a GPIO or by having a second pin | |
1138 | connected to the bus. If this option is defined a | |
1139 | custom i2c_init_board() routine in boards/xxx/board.c | |
1140 | is run early in the boot sequence. | |
47cd00fa | 1141 | |
bb99ad6d BW |
1142 | CONFIG_I2C_MULTI_BUS |
1143 | ||
1144 | This option allows the use of multiple I2C buses, each of which | |
c0f40859 WD |
1145 | must have a controller. At any point in time, only one bus is |
1146 | active. To switch to a different bus, use the 'i2c dev' command. | |
bb99ad6d BW |
1147 | Note that bus numbering is zero-based. |
1148 | ||
6d0f6bcf | 1149 | CONFIG_SYS_I2C_NOPROBES |
bb99ad6d BW |
1150 | |
1151 | This option specifies a list of I2C devices that will be skipped | |
c0f40859 | 1152 | when the 'i2c probe' command is issued. If CONFIG_I2C_MULTI_BUS |
0f89c54b PT |
1153 | is set, specify a list of bus-device pairs. Otherwise, specify |
1154 | a 1D array of device addresses | |
bb99ad6d BW |
1155 | |
1156 | e.g. | |
1157 | #undef CONFIG_I2C_MULTI_BUS | |
c0f40859 | 1158 | #define CONFIG_SYS_I2C_NOPROBES {0x50,0x68} |
bb99ad6d BW |
1159 | |
1160 | will skip addresses 0x50 and 0x68 on a board with one I2C bus | |
1161 | ||
c0f40859 | 1162 | #define CONFIG_I2C_MULTI_BUS |
945a18e6 | 1163 | #define CONFIG_SYS_I2C_NOPROBES {{0,0x50},{0,0x68},{1,0x54}} |
bb99ad6d BW |
1164 | |
1165 | will skip addresses 0x50 and 0x68 on bus 0 and address 0x54 on bus 1 | |
1166 | ||
6d0f6bcf | 1167 | CONFIG_SYS_RTC_BUS_NUM |
0dc018ec SR |
1168 | |
1169 | If defined, then this indicates the I2C bus number for the RTC. | |
1170 | If not defined, then U-Boot assumes that RTC is on I2C bus 0. | |
1171 | ||
2ac6985a AD |
1172 | CONFIG_SOFT_I2C_READ_REPEATED_START |
1173 | ||
1174 | defining this will force the i2c_read() function in | |
1175 | the soft_i2c driver to perform an I2C repeated start | |
1176 | between writing the address pointer and reading the | |
1177 | data. If this define is omitted the default behaviour | |
1178 | of doing a stop-start sequence will be used. Most I2C | |
1179 | devices can use either method, but some require one or | |
1180 | the other. | |
be5e6181 | 1181 | |
c609719b WD |
1182 | - SPI Support: CONFIG_SPI |
1183 | ||
1184 | Enables SPI driver (so far only tested with | |
1185 | SPI EEPROM, also an instance works with Crystal A/D and | |
1186 | D/As on the SACSng board) | |
1187 | ||
f659b573 HS |
1188 | CONFIG_SYS_SPI_MXC_WAIT |
1189 | Timeout for waiting until spi transfer completed. | |
1190 | default: (CONFIG_SYS_HZ/100) /* 10 ms */ | |
1191 | ||
0133502e | 1192 | - FPGA Support: CONFIG_FPGA |
c609719b | 1193 | |
0133502e MF |
1194 | Enables FPGA subsystem. |
1195 | ||
1196 | CONFIG_FPGA_<vendor> | |
1197 | ||
1198 | Enables support for specific chip vendors. | |
1199 | (ALTERA, XILINX) | |
c609719b | 1200 | |
0133502e | 1201 | CONFIG_FPGA_<family> |
c609719b | 1202 | |
0133502e MF |
1203 | Enables support for FPGA family. |
1204 | (SPARTAN2, SPARTAN3, VIRTEX2, CYCLONE2, ACEX1K, ACEX) | |
1205 | ||
6d0f6bcf | 1206 | CONFIG_SYS_FPGA_CHECK_BUSY |
c609719b | 1207 | |
43d9616c WD |
1208 | Enable checks on FPGA configuration interface busy |
1209 | status by the configuration function. This option | |
1210 | will require a board or device specific function to | |
1211 | be written. | |
c609719b WD |
1212 | |
1213 | CONFIG_FPGA_DELAY | |
1214 | ||
1215 | If defined, a function that provides delays in the FPGA | |
1216 | configuration driver. | |
1217 | ||
6d0f6bcf | 1218 | CONFIG_SYS_FPGA_CHECK_ERROR |
c609719b | 1219 | |
43d9616c WD |
1220 | Check for configuration errors during FPGA bitfile |
1221 | loading. For example, abort during Virtex II | |
1222 | configuration if the INIT_B line goes low (which | |
1223 | indicated a CRC error). | |
c609719b | 1224 | |
6d0f6bcf | 1225 | CONFIG_SYS_FPGA_WAIT_INIT |
c609719b | 1226 | |
b445bbb4 JM |
1227 | Maximum time to wait for the INIT_B line to de-assert |
1228 | after PROB_B has been de-asserted during a Virtex II | |
43d9616c | 1229 | FPGA configuration sequence. The default time is 500 |
11ccc33f | 1230 | ms. |
c609719b | 1231 | |
6d0f6bcf | 1232 | CONFIG_SYS_FPGA_WAIT_BUSY |
c609719b | 1233 | |
b445bbb4 | 1234 | Maximum time to wait for BUSY to de-assert during |
11ccc33f | 1235 | Virtex II FPGA configuration. The default is 5 ms. |
c609719b | 1236 | |
6d0f6bcf | 1237 | CONFIG_SYS_FPGA_WAIT_CONFIG |
c609719b | 1238 | |
43d9616c | 1239 | Time to wait after FPGA configuration. The default is |
11ccc33f | 1240 | 200 ms. |
c609719b | 1241 | |
c609719b WD |
1242 | - Vendor Parameter Protection: |
1243 | ||
43d9616c WD |
1244 | U-Boot considers the values of the environment |
1245 | variables "serial#" (Board Serial Number) and | |
7152b1d0 | 1246 | "ethaddr" (Ethernet Address) to be parameters that |
43d9616c WD |
1247 | are set once by the board vendor / manufacturer, and |
1248 | protects these variables from casual modification by | |
1249 | the user. Once set, these variables are read-only, | |
1250 | and write or delete attempts are rejected. You can | |
11ccc33f | 1251 | change this behaviour: |
c609719b WD |
1252 | |
1253 | If CONFIG_ENV_OVERWRITE is #defined in your config | |
1254 | file, the write protection for vendor parameters is | |
47cd00fa | 1255 | completely disabled. Anybody can change or delete |
c609719b WD |
1256 | these parameters. |
1257 | ||
92ac5208 JH |
1258 | Alternatively, if you define _both_ an ethaddr in the |
1259 | default env _and_ CONFIG_OVERWRITE_ETHADDR_ONCE, a default | |
11ccc33f | 1260 | Ethernet address is installed in the environment, |
c609719b WD |
1261 | which can be changed exactly ONCE by the user. [The |
1262 | serial# is unaffected by this, i. e. it remains | |
1263 | read-only.] | |
1264 | ||
2598090b JH |
1265 | The same can be accomplished in a more flexible way |
1266 | for any variable by configuring the type of access | |
1267 | to allow for those variables in the ".flags" variable | |
1268 | or define CONFIG_ENV_FLAGS_LIST_STATIC. | |
1269 | ||
c609719b WD |
1270 | - Protected RAM: |
1271 | CONFIG_PRAM | |
1272 | ||
1273 | Define this variable to enable the reservation of | |
1274 | "protected RAM", i. e. RAM which is not overwritten | |
1275 | by U-Boot. Define CONFIG_PRAM to hold the number of | |
1276 | kB you want to reserve for pRAM. You can overwrite | |
1277 | this default value by defining an environment | |
1278 | variable "pram" to the number of kB you want to | |
1279 | reserve. Note that the board info structure will | |
1280 | still show the full amount of RAM. If pRAM is | |
1281 | reserved, a new environment variable "mem" will | |
1282 | automatically be defined to hold the amount of | |
1283 | remaining RAM in a form that can be passed as boot | |
1284 | argument to Linux, for instance like that: | |
1285 | ||
fe126d8b | 1286 | setenv bootargs ... mem=\${mem} |
c609719b WD |
1287 | saveenv |
1288 | ||
1289 | This way you can tell Linux not to use this memory, | |
1290 | either, which results in a memory region that will | |
1291 | not be affected by reboots. | |
1292 | ||
1293 | *WARNING* If your board configuration uses automatic | |
1294 | detection of the RAM size, you must make sure that | |
1295 | this memory test is non-destructive. So far, the | |
1296 | following board configurations are known to be | |
1297 | "pRAM-clean": | |
1298 | ||
5b8e76c3 | 1299 | IVMS8, IVML24, SPD8xx, |
1b0757ec | 1300 | HERMES, IP860, RPXlite, LWMON, |
2eb48ff7 | 1301 | FLAGADM |
c609719b WD |
1302 | |
1303 | - Error Recovery: | |
c609719b WD |
1304 | Note: |
1305 | ||
8bde7f77 WD |
1306 | In the current implementation, the local variables |
1307 | space and global environment variables space are | |
1308 | separated. Local variables are those you define by | |
1309 | simply typing `name=value'. To access a local | |
1310 | variable later on, you have write `$name' or | |
1311 | `${name}'; to execute the contents of a variable | |
1312 | directly type `$name' at the command prompt. | |
c609719b | 1313 | |
43d9616c WD |
1314 | Global environment variables are those you use |
1315 | setenv/printenv to work with. To run a command stored | |
1316 | in such a variable, you need to use the run command, | |
1317 | and you must not use the '$' sign to access them. | |
c609719b WD |
1318 | |
1319 | To store commands and special characters in a | |
1320 | variable, please use double quotation marks | |
1321 | surrounding the whole text of the variable, instead | |
1322 | of the backslashes before semicolons and special | |
1323 | symbols. | |
1324 | ||
a8c7c708 | 1325 | - Default Environment: |
c609719b WD |
1326 | CONFIG_EXTRA_ENV_SETTINGS |
1327 | ||
43d9616c WD |
1328 | Define this to contain any number of null terminated |
1329 | strings (variable = value pairs) that will be part of | |
7152b1d0 | 1330 | the default environment compiled into the boot image. |
2262cfee | 1331 | |
43d9616c WD |
1332 | For example, place something like this in your |
1333 | board's config file: | |
c609719b WD |
1334 | |
1335 | #define CONFIG_EXTRA_ENV_SETTINGS \ | |
1336 | "myvar1=value1\0" \ | |
1337 | "myvar2=value2\0" | |
1338 | ||
43d9616c WD |
1339 | Warning: This method is based on knowledge about the |
1340 | internal format how the environment is stored by the | |
1341 | U-Boot code. This is NOT an official, exported | |
1342 | interface! Although it is unlikely that this format | |
7152b1d0 | 1343 | will change soon, there is no guarantee either. |
c609719b WD |
1344 | You better know what you are doing here. |
1345 | ||
43d9616c WD |
1346 | Note: overly (ab)use of the default environment is |
1347 | discouraged. Make sure to check other ways to preset | |
74de7aef | 1348 | the environment like the "source" command or the |
43d9616c | 1349 | boot command first. |
c609719b | 1350 | |
06fd8538 SG |
1351 | CONFIG_DELAY_ENVIRONMENT |
1352 | ||
1353 | Normally the environment is loaded when the board is | |
b445bbb4 | 1354 | initialised so that it is available to U-Boot. This inhibits |
06fd8538 SG |
1355 | that so that the environment is not available until |
1356 | explicitly loaded later by U-Boot code. With CONFIG_OF_CONTROL | |
1357 | this is instead controlled by the value of | |
1358 | /config/load-environment. | |
1359 | ||
4cf2609b WD |
1360 | CONFIG_STANDALONE_LOAD_ADDR |
1361 | ||
6feff899 WD |
1362 | This option defines a board specific value for the |
1363 | address where standalone program gets loaded, thus | |
1364 | overwriting the architecture dependent default | |
4cf2609b WD |
1365 | settings. |
1366 | ||
cccfc2ab DZ |
1367 | - Automatic software updates via TFTP server |
1368 | CONFIG_UPDATE_TFTP | |
1369 | CONFIG_UPDATE_TFTP_CNT_MAX | |
1370 | CONFIG_UPDATE_TFTP_MSEC_MAX | |
1371 | ||
1372 | These options enable and control the auto-update feature; | |
1373 | for a more detailed description refer to doc/README.update. | |
1374 | ||
1375 | - MTD Support (mtdparts command, UBI support) | |
ff94bc40 HS |
1376 | CONFIG_MTD_UBI_WL_THRESHOLD |
1377 | This parameter defines the maximum difference between the highest | |
1378 | erase counter value and the lowest erase counter value of eraseblocks | |
1379 | of UBI devices. When this threshold is exceeded, UBI starts performing | |
1380 | wear leveling by means of moving data from eraseblock with low erase | |
1381 | counter to eraseblocks with high erase counter. | |
1382 | ||
1383 | The default value should be OK for SLC NAND flashes, NOR flashes and | |
1384 | other flashes which have eraseblock life-cycle 100000 or more. | |
1385 | However, in case of MLC NAND flashes which typically have eraseblock | |
1386 | life-cycle less than 10000, the threshold should be lessened (e.g., | |
1387 | to 128 or 256, although it does not have to be power of 2). | |
1388 | ||
1389 | default: 4096 | |
c654b517 | 1390 | |
ff94bc40 HS |
1391 | CONFIG_MTD_UBI_BEB_LIMIT |
1392 | This option specifies the maximum bad physical eraseblocks UBI | |
1393 | expects on the MTD device (per 1024 eraseblocks). If the | |
1394 | underlying flash does not admit of bad eraseblocks (e.g. NOR | |
1395 | flash), this value is ignored. | |
1396 | ||
1397 | NAND datasheets often specify the minimum and maximum NVM | |
1398 | (Number of Valid Blocks) for the flashes' endurance lifetime. | |
1399 | The maximum expected bad eraseblocks per 1024 eraseblocks | |
1400 | then can be calculated as "1024 * (1 - MinNVB / MaxNVB)", | |
1401 | which gives 20 for most NANDs (MaxNVB is basically the total | |
1402 | count of eraseblocks on the chip). | |
1403 | ||
1404 | To put it differently, if this value is 20, UBI will try to | |
1405 | reserve about 1.9% of physical eraseblocks for bad blocks | |
1406 | handling. And that will be 1.9% of eraseblocks on the entire | |
1407 | NAND chip, not just the MTD partition UBI attaches. This means | |
1408 | that if you have, say, a NAND flash chip admits maximum 40 bad | |
1409 | eraseblocks, and it is split on two MTD partitions of the same | |
1410 | size, UBI will reserve 40 eraseblocks when attaching a | |
1411 | partition. | |
1412 | ||
1413 | default: 20 | |
1414 | ||
1415 | CONFIG_MTD_UBI_FASTMAP | |
1416 | Fastmap is a mechanism which allows attaching an UBI device | |
1417 | in nearly constant time. Instead of scanning the whole MTD device it | |
1418 | only has to locate a checkpoint (called fastmap) on the device. | |
1419 | The on-flash fastmap contains all information needed to attach | |
1420 | the device. Using fastmap makes only sense on large devices where | |
1421 | attaching by scanning takes long. UBI will not automatically install | |
1422 | a fastmap on old images, but you can set the UBI parameter | |
1423 | CONFIG_MTD_UBI_FASTMAP_AUTOCONVERT to 1 if you want so. Please note | |
1424 | that fastmap-enabled images are still usable with UBI implementations | |
1425 | without fastmap support. On typical flash devices the whole fastmap | |
1426 | fits into one PEB. UBI will reserve PEBs to hold two fastmaps. | |
1427 | ||
1428 | CONFIG_MTD_UBI_FASTMAP_AUTOCONVERT | |
1429 | Set this parameter to enable fastmap automatically on images | |
1430 | without a fastmap. | |
1431 | default: 0 | |
1432 | ||
0195a7bb HS |
1433 | CONFIG_MTD_UBI_FM_DEBUG |
1434 | Enable UBI fastmap debug | |
1435 | default: 0 | |
1436 | ||
6a11cf48 | 1437 | - SPL framework |
04e5ae79 WD |
1438 | CONFIG_SPL |
1439 | Enable building of SPL globally. | |
6a11cf48 | 1440 | |
8c80eb3b AA |
1441 | CONFIG_SPL_PANIC_ON_RAW_IMAGE |
1442 | When defined, SPL will panic() if the image it has | |
1443 | loaded does not have a signature. | |
1444 | Defining this is useful when code which loads images | |
1445 | in SPL cannot guarantee that absolutely all read errors | |
1446 | will be caught. | |
1447 | An example is the LPC32XX MLC NAND driver, which will | |
1448 | consider that a completely unreadable NAND block is bad, | |
1449 | and thus should be skipped silently. | |
1450 | ||
861a86f4 TR |
1451 | CONFIG_SPL_DISPLAY_PRINT |
1452 | For ARM, enable an optional function to print more information | |
1453 | about the running system. | |
1454 | ||
06f60ae3 SW |
1455 | CONFIG_SPL_MPC83XX_WAIT_FOR_NAND |
1456 | Set this for NAND SPL on PPC mpc83xx targets, so that | |
1457 | start.S waits for the rest of the SPL to load before | |
1458 | continuing (the hardware starts execution after just | |
1459 | loading the first page rather than the full 4K). | |
1460 | ||
6f4e7d3c TG |
1461 | CONFIG_SPL_UBI |
1462 | Support for a lightweight UBI (fastmap) scanner and | |
1463 | loader | |
1464 | ||
95579793 TR |
1465 | CONFIG_SYS_NAND_5_ADDR_CYCLE, CONFIG_SYS_NAND_PAGE_COUNT, |
1466 | CONFIG_SYS_NAND_PAGE_SIZE, CONFIG_SYS_NAND_OOBSIZE, | |
1467 | CONFIG_SYS_NAND_BLOCK_SIZE, CONFIG_SYS_NAND_BAD_BLOCK_POS, | |
1468 | CONFIG_SYS_NAND_ECCPOS, CONFIG_SYS_NAND_ECCSIZE, | |
1469 | CONFIG_SYS_NAND_ECCBYTES | |
1470 | Defines the size and behavior of the NAND that SPL uses | |
7d4b7955 | 1471 | to read U-Boot |
95579793 | 1472 | |
7d4b7955 SW |
1473 | CONFIG_SYS_NAND_U_BOOT_DST |
1474 | Location in memory to load U-Boot to | |
1475 | ||
1476 | CONFIG_SYS_NAND_U_BOOT_SIZE | |
1477 | Size of image to load | |
95579793 TR |
1478 | |
1479 | CONFIG_SYS_NAND_U_BOOT_START | |
7d4b7955 | 1480 | Entry point in loaded image to jump to |
95579793 TR |
1481 | |
1482 | CONFIG_SYS_NAND_HW_ECC_OOBFIRST | |
1483 | Define this if you need to first read the OOB and then the | |
b445bbb4 | 1484 | data. This is used, for example, on davinci platforms. |
95579793 | 1485 | |
c57b953d PM |
1486 | CONFIG_SPL_RAM_DEVICE |
1487 | Support for running image already present in ram, in SPL binary | |
6a11cf48 | 1488 | |
b527b9c6 | 1489 | CONFIG_SPL_FIT_PRINT |
87ebee39 SG |
1490 | Printing information about a FIT image adds quite a bit of |
1491 | code to SPL. So this is normally disabled in SPL. Use this | |
1492 | option to re-enable it. This will affect the output of the | |
1493 | bootm command when booting a FIT image. | |
1494 | ||
a8c7c708 WD |
1495 | - Interrupt support (PPC): |
1496 | ||
d4ca31c4 WD |
1497 | There are common interrupt_init() and timer_interrupt() |
1498 | for all PPC archs. interrupt_init() calls interrupt_init_cpu() | |
11ccc33f | 1499 | for CPU specific initialization. interrupt_init_cpu() |
d4ca31c4 | 1500 | should set decrementer_count to appropriate value. If |
11ccc33f | 1501 | CPU resets decrementer automatically after interrupt |
d4ca31c4 | 1502 | (ppc4xx) it should set decrementer_count to zero. |
11ccc33f | 1503 | timer_interrupt() calls timer_interrupt_cpu() for CPU |
d4ca31c4 WD |
1504 | specific handling. If board has watchdog / status_led |
1505 | / other_activity_monitor it works automatically from | |
1506 | general timer_interrupt(). | |
a8c7c708 | 1507 | |
c609719b | 1508 | |
9660e442 HR |
1509 | Board initialization settings: |
1510 | ------------------------------ | |
1511 | ||
1512 | During Initialization u-boot calls a number of board specific functions | |
1513 | to allow the preparation of board specific prerequisites, e.g. pin setup | |
1514 | before drivers are initialized. To enable these callbacks the | |
1515 | following configuration macros have to be defined. Currently this is | |
1516 | architecture specific, so please check arch/your_architecture/lib/board.c | |
1517 | typically in board_init_f() and board_init_r(). | |
1518 | ||
1519 | - CONFIG_BOARD_EARLY_INIT_F: Call board_early_init_f() | |
1520 | - CONFIG_BOARD_EARLY_INIT_R: Call board_early_init_r() | |
1521 | - CONFIG_BOARD_LATE_INIT: Call board_late_init() | |
c609719b | 1522 | |
c609719b WD |
1523 | Configuration Settings: |
1524 | ----------------------- | |
1525 | ||
4d979bfd | 1526 | - MEM_SUPPORT_64BIT_DATA: Defined automatically if compiled as 64-bit. |
4d1fd7f1 YS |
1527 | Optionally it can be defined to support 64-bit memory commands. |
1528 | ||
6d0f6bcf | 1529 | - CONFIG_SYS_LONGHELP: Defined when you want long help messages included; |
c609719b WD |
1530 | undefine this when you're short of memory. |
1531 | ||
2fb2604d PT |
1532 | - CONFIG_SYS_HELP_CMD_WIDTH: Defined when you want to override the default |
1533 | width of the commands listed in the 'help' command output. | |
1534 | ||
6d0f6bcf | 1535 | - CONFIG_SYS_PROMPT: This is what U-Boot prints on the console to |
c609719b WD |
1536 | prompt for user input. |
1537 | ||
6d0f6bcf | 1538 | - CONFIG_SYS_BAUDRATE_TABLE: |
c609719b WD |
1539 | List of legal baudrate settings for this board. |
1540 | ||
e8149522 | 1541 | - CONFIG_SYS_MEM_RESERVE_SECURE |
e61a7534 | 1542 | Only implemented for ARMv8 for now. |
e8149522 YS |
1543 | If defined, the size of CONFIG_SYS_MEM_RESERVE_SECURE memory |
1544 | is substracted from total RAM and won't be reported to OS. | |
1545 | This memory can be used as secure memory. A variable | |
e61a7534 | 1546 | gd->arch.secure_ram is used to track the location. In systems |
e8149522 YS |
1547 | the RAM base is not zero, or RAM is divided into banks, |
1548 | this variable needs to be recalcuated to get the address. | |
1549 | ||
6d0f6bcf | 1550 | - CONFIG_SYS_LOADS_BAUD_CHANGE: |
c609719b WD |
1551 | Enable temporary baudrate change while serial download |
1552 | ||
6d0f6bcf | 1553 | - CONFIG_SYS_SDRAM_BASE: |
c609719b WD |
1554 | Physical start address of SDRAM. _Must_ be 0 here. |
1555 | ||
6d0f6bcf | 1556 | - CONFIG_SYS_FLASH_BASE: |
c609719b WD |
1557 | Physical start address of Flash memory. |
1558 | ||
6d0f6bcf | 1559 | - CONFIG_SYS_MONITOR_LEN: |
8bde7f77 WD |
1560 | Size of memory reserved for monitor code, used to |
1561 | determine _at_compile_time_ (!) if the environment is | |
1562 | embedded within the U-Boot image, or in a separate | |
1563 | flash sector. | |
c609719b | 1564 | |
6d0f6bcf | 1565 | - CONFIG_SYS_MALLOC_LEN: |
c609719b WD |
1566 | Size of DRAM reserved for malloc() use. |
1567 | ||
d59476b6 SG |
1568 | - CONFIG_SYS_MALLOC_F_LEN |
1569 | Size of the malloc() pool for use before relocation. If | |
1570 | this is defined, then a very simple malloc() implementation | |
1571 | will become available before relocation. The address is just | |
1572 | below the global data, and the stack is moved down to make | |
1573 | space. | |
1574 | ||
1575 | This feature allocates regions with increasing addresses | |
1576 | within the region. calloc() is supported, but realloc() | |
1577 | is not available. free() is supported but does nothing. | |
b445bbb4 | 1578 | The memory will be freed (or in fact just forgotten) when |
d59476b6 SG |
1579 | U-Boot relocates itself. |
1580 | ||
38687ae6 SG |
1581 | - CONFIG_SYS_MALLOC_SIMPLE |
1582 | Provides a simple and small malloc() and calloc() for those | |
1583 | boards which do not use the full malloc in SPL (which is | |
10f6e4dc | 1584 | enabled with CONFIG_SYS_SPL_MALLOC). |
38687ae6 | 1585 | |
1dfdd9ba TR |
1586 | - CONFIG_SYS_NONCACHED_MEMORY: |
1587 | Size of non-cached memory area. This area of memory will be | |
1588 | typically located right below the malloc() area and mapped | |
1589 | uncached in the MMU. This is useful for drivers that would | |
1590 | otherwise require a lot of explicit cache maintenance. For | |
1591 | some drivers it's also impossible to properly maintain the | |
1592 | cache. For example if the regions that need to be flushed | |
1593 | are not a multiple of the cache-line size, *and* padding | |
1594 | cannot be allocated between the regions to align them (i.e. | |
1595 | if the HW requires a contiguous array of regions, and the | |
1596 | size of each region is not cache-aligned), then a flush of | |
1597 | one region may result in overwriting data that hardware has | |
1598 | written to another region in the same cache-line. This can | |
1599 | happen for example in network drivers where descriptors for | |
1600 | buffers are typically smaller than the CPU cache-line (e.g. | |
1601 | 16 bytes vs. 32 or 64 bytes). | |
1602 | ||
1603 | Non-cached memory is only supported on 32-bit ARM at present. | |
1604 | ||
6d0f6bcf | 1605 | - CONFIG_SYS_BOOTMAPSZ: |
c609719b WD |
1606 | Maximum size of memory mapped by the startup code of |
1607 | the Linux kernel; all data that must be processed by | |
7d721e34 BS |
1608 | the Linux kernel (bd_info, boot arguments, FDT blob if |
1609 | used) must be put below this limit, unless "bootm_low" | |
1bce2aeb | 1610 | environment variable is defined and non-zero. In such case |
7d721e34 | 1611 | all data for the Linux kernel must be between "bootm_low" |
c0f40859 | 1612 | and "bootm_low" + CONFIG_SYS_BOOTMAPSZ. The environment |
c3624e6e GL |
1613 | variable "bootm_mapsize" will override the value of |
1614 | CONFIG_SYS_BOOTMAPSZ. If CONFIG_SYS_BOOTMAPSZ is undefined, | |
1615 | then the value in "bootm_size" will be used instead. | |
c609719b | 1616 | |
fca43cc8 JR |
1617 | - CONFIG_SYS_BOOT_GET_CMDLINE: |
1618 | Enables allocating and saving kernel cmdline in space between | |
1619 | "bootm_low" and "bootm_low" + BOOTMAPSZ. | |
1620 | ||
1621 | - CONFIG_SYS_BOOT_GET_KBD: | |
1622 | Enables allocating and saving a kernel copy of the bd_info in | |
1623 | space between "bootm_low" and "bootm_low" + BOOTMAPSZ. | |
1624 | ||
6d0f6bcf | 1625 | - CONFIG_SYS_FLASH_PROTECTION |
8564acf9 WD |
1626 | If defined, hardware flash sectors protection is used |
1627 | instead of U-Boot software protection. | |
1628 | ||
6d0f6bcf | 1629 | - CONFIG_SYS_FLASH_CFI: |
43d9616c | 1630 | Define if the flash driver uses extra elements in the |
5653fc33 WD |
1631 | common flash structure for storing flash geometry. |
1632 | ||
00b1883a | 1633 | - CONFIG_FLASH_CFI_DRIVER |
5653fc33 WD |
1634 | This option also enables the building of the cfi_flash driver |
1635 | in the drivers directory | |
c609719b | 1636 | |
91809ed5 PZ |
1637 | - CONFIG_FLASH_CFI_MTD |
1638 | This option enables the building of the cfi_mtd driver | |
1639 | in the drivers directory. The driver exports CFI flash | |
1640 | to the MTD layer. | |
1641 | ||
6d0f6bcf | 1642 | - CONFIG_SYS_FLASH_USE_BUFFER_WRITE |
96ef831f GL |
1643 | Use buffered writes to flash. |
1644 | ||
1645 | - CONFIG_FLASH_SPANSION_S29WS_N | |
1646 | s29ws-n MirrorBit flash has non-standard addresses for buffered | |
1647 | write commands. | |
1648 | ||
9a042e9c JVB |
1649 | - CONFIG_FLASH_SHOW_PROGRESS |
1650 | If defined (must be an integer), print out countdown | |
1651 | digits and dots. Recommended value: 45 (9..1) for 80 | |
1652 | column displays, 15 (3..1) for 40 column displays. | |
1653 | ||
352ef3f1 SR |
1654 | - CONFIG_FLASH_VERIFY |
1655 | If defined, the content of the flash (destination) is compared | |
1656 | against the source after the write operation. An error message | |
1657 | will be printed when the contents are not identical. | |
1658 | Please note that this option is useless in nearly all cases, | |
1659 | since such flash programming errors usually are detected earlier | |
1660 | while unprotecting/erasing/programming. Please only enable | |
1661 | this option if you really know what you are doing. | |
1662 | ||
2598090b JH |
1663 | - CONFIG_ENV_FLAGS_LIST_DEFAULT |
1664 | - CONFIG_ENV_FLAGS_LIST_STATIC | |
1bce2aeb | 1665 | Enable validation of the values given to environment variables when |
2598090b JH |
1666 | calling env set. Variables can be restricted to only decimal, |
1667 | hexadecimal, or boolean. If CONFIG_CMD_NET is also defined, | |
1668 | the variables can also be restricted to IP address or MAC address. | |
1669 | ||
1670 | The format of the list is: | |
1671 | type_attribute = [s|d|x|b|i|m] | |
b445bbb4 JM |
1672 | access_attribute = [a|r|o|c] |
1673 | attributes = type_attribute[access_attribute] | |
2598090b JH |
1674 | entry = variable_name[:attributes] |
1675 | list = entry[,list] | |
1676 | ||
1677 | The type attributes are: | |
1678 | s - String (default) | |
1679 | d - Decimal | |
1680 | x - Hexadecimal | |
1681 | b - Boolean ([1yYtT|0nNfF]) | |
1682 | i - IP address | |
1683 | m - MAC address | |
1684 | ||
267541f7 JH |
1685 | The access attributes are: |
1686 | a - Any (default) | |
1687 | r - Read-only | |
1688 | o - Write-once | |
1689 | c - Change-default | |
1690 | ||
2598090b JH |
1691 | - CONFIG_ENV_FLAGS_LIST_DEFAULT |
1692 | Define this to a list (string) to define the ".flags" | |
b445bbb4 | 1693 | environment variable in the default or embedded environment. |
2598090b JH |
1694 | |
1695 | - CONFIG_ENV_FLAGS_LIST_STATIC | |
1696 | Define this to a list (string) to define validation that | |
1697 | should be done if an entry is not found in the ".flags" | |
1698 | environment variable. To override a setting in the static | |
1699 | list, simply add an entry for the same variable name to the | |
1700 | ".flags" variable. | |
1701 | ||
bdf1fe4e JH |
1702 | If CONFIG_REGEX is defined, the variable_name above is evaluated as a |
1703 | regular expression. This allows multiple variables to define the same | |
1704 | flags without explicitly listing them for each variable. | |
1705 | ||
c609719b WD |
1706 | The following definitions that deal with the placement and management |
1707 | of environment data (variable area); in general, we support the | |
1708 | following configurations: | |
1709 | ||
c3eb3fe4 MF |
1710 | - CONFIG_BUILD_ENVCRC: |
1711 | ||
1712 | Builds up envcrc with the target environment so that external utils | |
1713 | may easily extract it and embed it in final U-Boot images. | |
1714 | ||
c609719b | 1715 | BE CAREFUL! The first access to the environment happens quite early |
b445bbb4 | 1716 | in U-Boot initialization (when we try to get the setting of for the |
11ccc33f | 1717 | console baudrate). You *MUST* have mapped your NVRAM area then, or |
c609719b WD |
1718 | U-Boot will hang. |
1719 | ||
1720 | Please note that even with NVRAM we still use a copy of the | |
1721 | environment in RAM: we could work on NVRAM directly, but we want to | |
1722 | keep settings there always unmodified except somebody uses "saveenv" | |
1723 | to save the current settings. | |
1724 | ||
0a85a9e7 LG |
1725 | BE CAREFUL! For some special cases, the local device can not use |
1726 | "saveenv" command. For example, the local device will get the | |
fc54c7fa LG |
1727 | environment stored in a remote NOR flash by SRIO or PCIE link, |
1728 | but it can not erase, write this NOR flash by SRIO or PCIE interface. | |
0a85a9e7 | 1729 | |
b74ab737 GL |
1730 | - CONFIG_NAND_ENV_DST |
1731 | ||
1732 | Defines address in RAM to which the nand_spl code should copy the | |
1733 | environment. If redundant environment is used, it will be copied to | |
1734 | CONFIG_NAND_ENV_DST + CONFIG_ENV_SIZE. | |
1735 | ||
e881cb56 | 1736 | Please note that the environment is read-only until the monitor |
c609719b | 1737 | has been relocated to RAM and a RAM copy of the environment has been |
00caae6d | 1738 | created; also, when using EEPROM you will have to use env_get_f() |
c609719b WD |
1739 | until then to read environment variables. |
1740 | ||
85ec0bcc WD |
1741 | The environment is protected by a CRC32 checksum. Before the monitor |
1742 | is relocated into RAM, as a result of a bad CRC you will be working | |
1743 | with the compiled-in default environment - *silently*!!! [This is | |
1744 | necessary, because the first environment variable we need is the | |
1745 | "baudrate" setting for the console - if we have a bad CRC, we don't | |
1746 | have any device yet where we could complain.] | |
c609719b WD |
1747 | |
1748 | Note: once the monitor has been relocated, then it will complain if | |
1749 | the default environment is used; a new CRC is computed as soon as you | |
85ec0bcc | 1750 | use the "saveenv" command to store a valid environment. |
c609719b | 1751 | |
6d0f6bcf | 1752 | - CONFIG_SYS_FAULT_MII_ADDR: |
42d1f039 | 1753 | MII address of the PHY to check for the Ethernet link state. |
c609719b | 1754 | |
f5675aa5 RM |
1755 | - CONFIG_NS16550_MIN_FUNCTIONS: |
1756 | Define this if you desire to only have use of the NS16550_init | |
1757 | and NS16550_putc functions for the serial driver located at | |
1758 | drivers/serial/ns16550.c. This option is useful for saving | |
1759 | space for already greatly restricted images, including but not | |
1760 | limited to NAND_SPL configurations. | |
1761 | ||
b2b92f53 SG |
1762 | - CONFIG_DISPLAY_BOARDINFO |
1763 | Display information about the board that U-Boot is running on | |
1764 | when U-Boot starts up. The board function checkboard() is called | |
1765 | to do this. | |
1766 | ||
e2e3e2b1 SG |
1767 | - CONFIG_DISPLAY_BOARDINFO_LATE |
1768 | Similar to the previous option, but display this information | |
1769 | later, once stdio is running and output goes to the LCD, if | |
1770 | present. | |
1771 | ||
c609719b | 1772 | Low Level (hardware related) configuration options: |
dc7c9a1a | 1773 | --------------------------------------------------- |
c609719b | 1774 | |
6d0f6bcf | 1775 | - CONFIG_SYS_CACHELINE_SIZE: |
c609719b WD |
1776 | Cache Line Size of the CPU. |
1777 | ||
e46fedfe TT |
1778 | - CONFIG_SYS_CCSRBAR_DEFAULT: |
1779 | Default (power-on reset) physical address of CCSR on Freescale | |
1780 | PowerPC SOCs. | |
1781 | ||
1782 | - CONFIG_SYS_CCSRBAR: | |
1783 | Virtual address of CCSR. On a 32-bit build, this is typically | |
1784 | the same value as CONFIG_SYS_CCSRBAR_DEFAULT. | |
1785 | ||
e46fedfe TT |
1786 | - CONFIG_SYS_CCSRBAR_PHYS: |
1787 | Physical address of CCSR. CCSR can be relocated to a new | |
1788 | physical address, if desired. In this case, this macro should | |
c0f40859 | 1789 | be set to that address. Otherwise, it should be set to the |
e46fedfe TT |
1790 | same value as CONFIG_SYS_CCSRBAR_DEFAULT. For example, CCSR |
1791 | is typically relocated on 36-bit builds. It is recommended | |
1792 | that this macro be defined via the _HIGH and _LOW macros: | |
1793 | ||
1794 | #define CONFIG_SYS_CCSRBAR_PHYS ((CONFIG_SYS_CCSRBAR_PHYS_HIGH | |
1795 | * 1ull) << 32 | CONFIG_SYS_CCSRBAR_PHYS_LOW) | |
1796 | ||
1797 | - CONFIG_SYS_CCSRBAR_PHYS_HIGH: | |
4cf2609b WD |
1798 | Bits 33-36 of CONFIG_SYS_CCSRBAR_PHYS. This value is typically |
1799 | either 0 (32-bit build) or 0xF (36-bit build). This macro is | |
e46fedfe TT |
1800 | used in assembly code, so it must not contain typecasts or |
1801 | integer size suffixes (e.g. "ULL"). | |
1802 | ||
1803 | - CONFIG_SYS_CCSRBAR_PHYS_LOW: | |
1804 | Lower 32-bits of CONFIG_SYS_CCSRBAR_PHYS. This macro is | |
1805 | used in assembly code, so it must not contain typecasts or | |
1806 | integer size suffixes (e.g. "ULL"). | |
1807 | ||
6d0f6bcf | 1808 | - CONFIG_SYS_IMMR: Physical address of the Internal Memory. |
efe2a4d5 | 1809 | DO NOT CHANGE unless you know exactly what you're |
907208c4 | 1810 | doing! (11-4) [MPC8xx systems only] |
c609719b | 1811 | |
6d0f6bcf | 1812 | - CONFIG_SYS_INIT_RAM_ADDR: |
c609719b | 1813 | |
7152b1d0 | 1814 | Start address of memory area that can be used for |
c609719b WD |
1815 | initial data and stack; please note that this must be |
1816 | writable memory that is working WITHOUT special | |
1817 | initialization, i. e. you CANNOT use normal RAM which | |
1818 | will become available only after programming the | |
1819 | memory controller and running certain initialization | |
1820 | sequences. | |
1821 | ||
1822 | U-Boot uses the following memory types: | |
907208c4 | 1823 | - MPC8xx: IMMR (internal memory of the CPU) |
c609719b | 1824 | |
6d0f6bcf | 1825 | - CONFIG_SYS_SCCR: System Clock and reset Control Register (15-27) |
c609719b | 1826 | |
6d0f6bcf | 1827 | - CONFIG_SYS_OR_TIMING_SDRAM: |
c609719b WD |
1828 | SDRAM timing |
1829 | ||
6d0f6bcf | 1830 | - CONFIG_SYS_MAMR_PTA: |
c609719b WD |
1831 | periodic timer for refresh |
1832 | ||
a09b9b68 KG |
1833 | - CONFIG_SYS_SRIO: |
1834 | Chip has SRIO or not | |
1835 | ||
1836 | - CONFIG_SRIO1: | |
1837 | Board has SRIO 1 port available | |
1838 | ||
1839 | - CONFIG_SRIO2: | |
1840 | Board has SRIO 2 port available | |
1841 | ||
c8b28152 LG |
1842 | - CONFIG_SRIO_PCIE_BOOT_MASTER |
1843 | Board can support master function for Boot from SRIO and PCIE | |
1844 | ||
a09b9b68 KG |
1845 | - CONFIG_SYS_SRIOn_MEM_VIRT: |
1846 | Virtual Address of SRIO port 'n' memory region | |
1847 | ||
62f9b654 | 1848 | - CONFIG_SYS_SRIOn_MEM_PHYxS: |
a09b9b68 KG |
1849 | Physical Address of SRIO port 'n' memory region |
1850 | ||
1851 | - CONFIG_SYS_SRIOn_MEM_SIZE: | |
1852 | Size of SRIO port 'n' memory region | |
1853 | ||
66bd1846 FE |
1854 | - CONFIG_SYS_NAND_BUSWIDTH_16BIT |
1855 | Defined to tell the NAND controller that the NAND chip is using | |
1856 | a 16 bit bus. | |
1857 | Not all NAND drivers use this symbol. | |
a430e916 | 1858 | Example of drivers that use it: |
a430fa06 MR |
1859 | - drivers/mtd/nand/raw/ndfc.c |
1860 | - drivers/mtd/nand/raw/mxc_nand.c | |
eced4626 AW |
1861 | |
1862 | - CONFIG_SYS_NDFC_EBC0_CFG | |
1863 | Sets the EBC0_CFG register for the NDFC. If not defined | |
1864 | a default value will be used. | |
1865 | ||
bb99ad6d | 1866 | - CONFIG_SPD_EEPROM |
218ca724 WD |
1867 | Get DDR timing information from an I2C EEPROM. Common |
1868 | with pluggable memory modules such as SODIMMs | |
1869 | ||
bb99ad6d BW |
1870 | SPD_EEPROM_ADDRESS |
1871 | I2C address of the SPD EEPROM | |
1872 | ||
6d0f6bcf | 1873 | - CONFIG_SYS_SPD_BUS_NUM |
218ca724 WD |
1874 | If SPD EEPROM is on an I2C bus other than the first |
1875 | one, specify here. Note that the value must resolve | |
1876 | to something your driver can deal with. | |
bb99ad6d | 1877 | |
6f5e1dc5 YS |
1878 | - CONFIG_FSL_DDR_INTERACTIVE |
1879 | Enable interactive DDR debugging. See doc/README.fsl-ddr. | |
1880 | ||
e32d59a2 YS |
1881 | - CONFIG_FSL_DDR_SYNC_REFRESH |
1882 | Enable sync of refresh for multiple controllers. | |
1883 | ||
4516ff81 YS |
1884 | - CONFIG_FSL_DDR_BIST |
1885 | Enable built-in memory test for Freescale DDR controllers. | |
1886 | ||
c26e454d WD |
1887 | - CONFIG_RMII |
1888 | Enable RMII mode for all FECs. | |
1889 | Note that this is a global option, we can't | |
1890 | have one FEC in standard MII mode and another in RMII mode. | |
1891 | ||
5cf91d6b WD |
1892 | - CONFIG_CRC32_VERIFY |
1893 | Add a verify option to the crc32 command. | |
1894 | The syntax is: | |
1895 | ||
1896 | => crc32 -v <address> <count> <crc32> | |
1897 | ||
1898 | Where address/count indicate a memory area | |
1899 | and crc32 is the correct crc32 which the | |
1900 | area should have. | |
1901 | ||
56523f12 WD |
1902 | - CONFIG_LOOPW |
1903 | Add the "loopw" memory command. This only takes effect if | |
493f420e | 1904 | the memory commands are activated globally (CONFIG_CMD_MEMORY). |
56523f12 | 1905 | |
72732318 | 1906 | - CONFIG_CMD_MX_CYCLIC |
7b466641 SR |
1907 | Add the "mdc" and "mwc" memory commands. These are cyclic |
1908 | "md/mw" commands. | |
1909 | Examples: | |
1910 | ||
efe2a4d5 | 1911 | => mdc.b 10 4 500 |
7b466641 SR |
1912 | This command will print 4 bytes (10,11,12,13) each 500 ms. |
1913 | ||
efe2a4d5 | 1914 | => mwc.l 100 12345678 10 |
7b466641 SR |
1915 | This command will write 12345678 to address 100 all 10 ms. |
1916 | ||
efe2a4d5 | 1917 | This only takes effect if the memory commands are activated |
493f420e | 1918 | globally (CONFIG_CMD_MEMORY). |
7b466641 | 1919 | |
401bb30b | 1920 | - CONFIG_SPL_BUILD |
32f2ca2a TH |
1921 | Set when the currently-running compilation is for an artifact |
1922 | that will end up in the SPL (as opposed to the TPL or U-Boot | |
1923 | proper). Code that needs stage-specific behavior should check | |
1924 | this. | |
400558b5 | 1925 | |
3aa29de0 | 1926 | - CONFIG_TPL_BUILD |
32f2ca2a TH |
1927 | Set when the currently-running compilation is for an artifact |
1928 | that will end up in the TPL (as opposed to the SPL or U-Boot | |
1929 | proper). Code that needs stage-specific behavior should check | |
1930 | this. | |
3aa29de0 | 1931 | |
4213fc29 SG |
1932 | - CONFIG_ARCH_MAP_SYSMEM |
1933 | Generally U-Boot (and in particular the md command) uses | |
1934 | effective address. It is therefore not necessary to regard | |
1935 | U-Boot address as virtual addresses that need to be translated | |
1936 | to physical addresses. However, sandbox requires this, since | |
1937 | it maintains its own little RAM buffer which contains all | |
1938 | addressable memory. This option causes some memory accesses | |
1939 | to be mapped through map_sysmem() / unmap_sysmem(). | |
1940 | ||
588a13f7 SG |
1941 | - CONFIG_X86_RESET_VECTOR |
1942 | If defined, the x86 reset vector code is included. This is not | |
1943 | needed when U-Boot is running from Coreboot. | |
b16f521a | 1944 | |
999d7d32 KM |
1945 | - CONFIG_SYS_NAND_NO_SUBPAGE_WRITE |
1946 | Option to disable subpage write in NAND driver | |
1947 | driver that uses this: | |
a430fa06 | 1948 | drivers/mtd/nand/raw/davinci_nand.c |
999d7d32 | 1949 | |
f2717b47 TT |
1950 | Freescale QE/FMAN Firmware Support: |
1951 | ----------------------------------- | |
1952 | ||
1953 | The Freescale QUICCEngine (QE) and Frame Manager (FMAN) both support the | |
1954 | loading of "firmware", which is encoded in the QE firmware binary format. | |
1955 | This firmware often needs to be loaded during U-Boot booting, so macros | |
1956 | are used to identify the storage device (NOR flash, SPI, etc) and the address | |
1957 | within that device. | |
1958 | ||
dcf1d774 ZQ |
1959 | - CONFIG_SYS_FMAN_FW_ADDR |
1960 | The address in the storage device where the FMAN microcode is located. The | |
cc1e98b5 | 1961 | meaning of this address depends on which CONFIG_SYS_QE_FMAN_FW_IN_xxx macro |
dcf1d774 ZQ |
1962 | is also specified. |
1963 | ||
1964 | - CONFIG_SYS_QE_FW_ADDR | |
1965 | The address in the storage device where the QE microcode is located. The | |
cc1e98b5 | 1966 | meaning of this address depends on which CONFIG_SYS_QE_FMAN_FW_IN_xxx macro |
f2717b47 TT |
1967 | is also specified. |
1968 | ||
1969 | - CONFIG_SYS_QE_FMAN_FW_LENGTH | |
1970 | The maximum possible size of the firmware. The firmware binary format | |
1971 | has a field that specifies the actual size of the firmware, but it | |
1972 | might not be possible to read any part of the firmware unless some | |
1973 | local storage is allocated to hold the entire firmware first. | |
1974 | ||
1975 | - CONFIG_SYS_QE_FMAN_FW_IN_NOR | |
1976 | Specifies that QE/FMAN firmware is located in NOR flash, mapped as | |
1977 | normal addressable memory via the LBC. CONFIG_SYS_FMAN_FW_ADDR is the | |
1978 | virtual address in NOR flash. | |
1979 | ||
1980 | - CONFIG_SYS_QE_FMAN_FW_IN_NAND | |
1981 | Specifies that QE/FMAN firmware is located in NAND flash. | |
1982 | CONFIG_SYS_FMAN_FW_ADDR is the offset within NAND flash. | |
1983 | ||
1984 | - CONFIG_SYS_QE_FMAN_FW_IN_MMC | |
1985 | Specifies that QE/FMAN firmware is located on the primary SD/MMC | |
1986 | device. CONFIG_SYS_FMAN_FW_ADDR is the byte offset on that device. | |
1987 | ||
292dc6c5 LG |
1988 | - CONFIG_SYS_QE_FMAN_FW_IN_REMOTE |
1989 | Specifies that QE/FMAN firmware is located in the remote (master) | |
1990 | memory space. CONFIG_SYS_FMAN_FW_ADDR is a virtual address which | |
fc54c7fa LG |
1991 | can be mapped from slave TLB->slave LAW->slave SRIO or PCIE outbound |
1992 | window->master inbound window->master LAW->the ucode address in | |
1993 | master's memory space. | |
f2717b47 | 1994 | |
b940ca64 GR |
1995 | Freescale Layerscape Management Complex Firmware Support: |
1996 | --------------------------------------------------------- | |
1997 | The Freescale Layerscape Management Complex (MC) supports the loading of | |
1998 | "firmware". | |
1999 | This firmware often needs to be loaded during U-Boot booting, so macros | |
2000 | are used to identify the storage device (NOR flash, SPI, etc) and the address | |
2001 | within that device. | |
2002 | ||
2003 | - CONFIG_FSL_MC_ENET | |
2004 | Enable the MC driver for Layerscape SoCs. | |
2005 | ||
5c055089 PK |
2006 | Freescale Layerscape Debug Server Support: |
2007 | ------------------------------------------- | |
2008 | The Freescale Layerscape Debug Server Support supports the loading of | |
2009 | "Debug Server firmware" and triggering SP boot-rom. | |
2010 | This firmware often needs to be loaded during U-Boot booting. | |
2011 | ||
c0492141 YS |
2012 | - CONFIG_SYS_MC_RSV_MEM_ALIGN |
2013 | Define alignment of reserved memory MC requires | |
5c055089 | 2014 | |
f3f431a7 PK |
2015 | Reproducible builds |
2016 | ------------------- | |
2017 | ||
2018 | In order to achieve reproducible builds, timestamps used in the U-Boot build | |
2019 | process have to be set to a fixed value. | |
2020 | ||
2021 | This is done using the SOURCE_DATE_EPOCH environment variable. | |
2022 | SOURCE_DATE_EPOCH is to be set on the build host's shell, not as a configuration | |
2023 | option for U-Boot or an environment variable in U-Boot. | |
2024 | ||
2025 | SOURCE_DATE_EPOCH should be set to a number of seconds since the epoch, in UTC. | |
2026 | ||
c609719b WD |
2027 | Building the Software: |
2028 | ====================== | |
2029 | ||
218ca724 WD |
2030 | Building U-Boot has been tested in several native build environments |
2031 | and in many different cross environments. Of course we cannot support | |
2032 | all possibly existing versions of cross development tools in all | |
2033 | (potentially obsolete) versions. In case of tool chain problems we | |
047f6ec0 | 2034 | recommend to use the ELDK (see https://www.denx.de/wiki/DULG/ELDK) |
218ca724 | 2035 | which is extensively used to build and test U-Boot. |
c609719b | 2036 | |
218ca724 WD |
2037 | If you are not using a native environment, it is assumed that you |
2038 | have GNU cross compiling tools available in your path. In this case, | |
2039 | you must set the environment variable CROSS_COMPILE in your shell. | |
2040 | Note that no changes to the Makefile or any other source files are | |
2041 | necessary. For example using the ELDK on a 4xx CPU, please enter: | |
c609719b | 2042 | |
218ca724 WD |
2043 | $ CROSS_COMPILE=ppc_4xx- |
2044 | $ export CROSS_COMPILE | |
c609719b | 2045 | |
218ca724 WD |
2046 | U-Boot is intended to be simple to build. After installing the |
2047 | sources you must configure U-Boot for one specific board type. This | |
c609719b WD |
2048 | is done by typing: |
2049 | ||
ab584d67 | 2050 | make NAME_defconfig |
c609719b | 2051 | |
ab584d67 | 2052 | where "NAME_defconfig" is the name of one of the existing configu- |
ecb3a0a1 | 2053 | rations; see configs/*_defconfig for supported names. |
db01a2ea | 2054 | |
ecb3a0a1 | 2055 | Note: for some boards special configuration names may exist; check if |
2729af9d WD |
2056 | additional information is available from the board vendor; for |
2057 | instance, the TQM823L systems are available without (standard) | |
2058 | or with LCD support. You can select such additional "features" | |
11ccc33f | 2059 | when choosing the configuration, i. e. |
2729af9d | 2060 | |
ab584d67 | 2061 | make TQM823L_defconfig |
2729af9d WD |
2062 | - will configure for a plain TQM823L, i. e. no LCD support |
2063 | ||
ab584d67 | 2064 | make TQM823L_LCD_defconfig |
2729af9d WD |
2065 | - will configure for a TQM823L with U-Boot console on LCD |
2066 | ||
2067 | etc. | |
2068 | ||
2069 | ||
2070 | Finally, type "make all", and you should get some working U-Boot | |
2071 | images ready for download to / installation on your system: | |
2072 | ||
2073 | - "u-boot.bin" is a raw binary image | |
2074 | - "u-boot" is an image in ELF binary format | |
2075 | - "u-boot.srec" is in Motorola S-Record format | |
2076 | ||
baf31249 MB |
2077 | By default the build is performed locally and the objects are saved |
2078 | in the source directory. One of the two methods can be used to change | |
2079 | this behavior and build U-Boot to some external directory: | |
2080 | ||
2081 | 1. Add O= to the make command line invocations: | |
2082 | ||
2083 | make O=/tmp/build distclean | |
ab584d67 | 2084 | make O=/tmp/build NAME_defconfig |
baf31249 MB |
2085 | make O=/tmp/build all |
2086 | ||
adbba996 | 2087 | 2. Set environment variable KBUILD_OUTPUT to point to the desired location: |
baf31249 | 2088 | |
adbba996 | 2089 | export KBUILD_OUTPUT=/tmp/build |
baf31249 | 2090 | make distclean |
ab584d67 | 2091 | make NAME_defconfig |
baf31249 MB |
2092 | make all |
2093 | ||
adbba996 | 2094 | Note that the command line "O=" setting overrides the KBUILD_OUTPUT environment |
baf31249 MB |
2095 | variable. |
2096 | ||
215bb1c1 DS |
2097 | User specific CPPFLAGS, AFLAGS and CFLAGS can be passed to the compiler by |
2098 | setting the according environment variables KCPPFLAGS, KAFLAGS and KCFLAGS. | |
2099 | For example to treat all compiler warnings as errors: | |
2100 | ||
2101 | make KCFLAGS=-Werror | |
2729af9d WD |
2102 | |
2103 | Please be aware that the Makefiles assume you are using GNU make, so | |
2104 | for instance on NetBSD you might need to use "gmake" instead of | |
2105 | native "make". | |
2106 | ||
2107 | ||
2108 | If the system board that you have is not listed, then you will need | |
2109 | to port U-Boot to your hardware platform. To do this, follow these | |
2110 | steps: | |
2111 | ||
3c1496cd | 2112 | 1. Create a new directory to hold your board specific code. Add any |
2729af9d | 2113 | files you need. In your board directory, you will need at least |
3c1496cd PS |
2114 | the "Makefile" and a "<board>.c". |
2115 | 2. Create a new configuration file "include/configs/<board>.h" for | |
2116 | your board. | |
2729af9d WD |
2117 | 3. If you're porting U-Boot to a new CPU, then also create a new |
2118 | directory to hold your CPU specific code. Add any files you need. | |
ab584d67 | 2119 | 4. Run "make <board>_defconfig" with your new name. |
2729af9d WD |
2120 | 5. Type "make", and you should get a working "u-boot.srec" file |
2121 | to be installed on your target system. | |
2122 | 6. Debug and solve any problems that might arise. | |
2123 | [Of course, this last step is much harder than it sounds.] | |
2124 | ||
2125 | ||
2126 | Testing of U-Boot Modifications, Ports to New Hardware, etc.: | |
2127 | ============================================================== | |
2128 | ||
218ca724 WD |
2129 | If you have modified U-Boot sources (for instance added a new board |
2130 | or support for new devices, a new CPU, etc.) you are expected to | |
2729af9d | 2131 | provide feedback to the other developers. The feedback normally takes |
32f2ca2a | 2132 | the form of a "patch", i.e. a context diff against a certain (latest |
218ca724 | 2133 | official or latest in the git repository) version of U-Boot sources. |
2729af9d | 2134 | |
218ca724 WD |
2135 | But before you submit such a patch, please verify that your modifi- |
2136 | cation did not break existing code. At least make sure that *ALL* of | |
2729af9d | 2137 | the supported boards compile WITHOUT ANY compiler warnings. To do so, |
6de80f21 SG |
2138 | just run the buildman script (tools/buildman/buildman), which will |
2139 | configure and build U-Boot for ALL supported system. Be warned, this | |
2140 | will take a while. Please see the buildman README, or run 'buildman -H' | |
2141 | for documentation. | |
baf31249 MB |
2142 | |
2143 | ||
2729af9d WD |
2144 | See also "U-Boot Porting Guide" below. |
2145 | ||
2146 | ||
2147 | Monitor Commands - Overview: | |
2148 | ============================ | |
2149 | ||
2150 | go - start application at address 'addr' | |
2151 | run - run commands in an environment variable | |
2152 | bootm - boot application image from memory | |
2153 | bootp - boot image via network using BootP/TFTP protocol | |
44f074c7 | 2154 | bootz - boot zImage from memory |
2729af9d WD |
2155 | tftpboot- boot image via network using TFTP protocol |
2156 | and env variables "ipaddr" and "serverip" | |
2157 | (and eventually "gatewayip") | |
1fb7cd49 | 2158 | tftpput - upload a file via network using TFTP protocol |
2729af9d WD |
2159 | rarpboot- boot image via network using RARP/TFTP protocol |
2160 | diskboot- boot from IDE devicebootd - boot default, i.e., run 'bootcmd' | |
2161 | loads - load S-Record file over serial line | |
2162 | loadb - load binary file over serial line (kermit mode) | |
bfef72e4 | 2163 | loadm - load binary blob from source address to destination address |
2729af9d WD |
2164 | md - memory display |
2165 | mm - memory modify (auto-incrementing) | |
2166 | nm - memory modify (constant address) | |
2167 | mw - memory write (fill) | |
bdded201 | 2168 | ms - memory search |
2729af9d WD |
2169 | cp - memory copy |
2170 | cmp - memory compare | |
2171 | crc32 - checksum calculation | |
0f89c54b | 2172 | i2c - I2C sub-system |
2729af9d WD |
2173 | sspi - SPI utility commands |
2174 | base - print or set address offset | |
2175 | printenv- print environment variables | |
9e9a530a | 2176 | pwm - control pwm channels |
2729af9d WD |
2177 | setenv - set environment variables |
2178 | saveenv - save environment variables to persistent storage | |
2179 | protect - enable or disable FLASH write protection | |
2180 | erase - erase FLASH memory | |
2181 | flinfo - print FLASH memory information | |
10635afa | 2182 | nand - NAND memory operations (see doc/README.nand) |
2729af9d WD |
2183 | bdinfo - print Board Info structure |
2184 | iminfo - print header information for application image | |
2185 | coninfo - print console devices and informations | |
2186 | ide - IDE sub-system | |
2187 | loop - infinite loop on address range | |
56523f12 | 2188 | loopw - infinite write loop on address range |
2729af9d WD |
2189 | mtest - simple RAM test |
2190 | icache - enable or disable instruction cache | |
2191 | dcache - enable or disable data cache | |
2192 | reset - Perform RESET of the CPU | |
2193 | echo - echo args to console | |
2194 | version - print monitor version | |
2195 | help - print online help | |
2196 | ? - alias for 'help' | |
2197 | ||
2198 | ||
2199 | Monitor Commands - Detailed Description: | |
2200 | ======================================== | |
2201 | ||
2202 | TODO. | |
2203 | ||
2204 | For now: just type "help <command>". | |
2205 | ||
2206 | ||
2729af9d WD |
2207 | Note for Redundant Ethernet Interfaces: |
2208 | ======================================= | |
c609719b | 2209 | |
11ccc33f | 2210 | Some boards come with redundant Ethernet interfaces; U-Boot supports |
2729af9d WD |
2211 | such configurations and is capable of automatic selection of a |
2212 | "working" interface when needed. MAC assignment works as follows: | |
c609719b | 2213 | |
2729af9d WD |
2214 | Network interfaces are numbered eth0, eth1, eth2, ... Corresponding |
2215 | MAC addresses can be stored in the environment as "ethaddr" (=>eth0), | |
2216 | "eth1addr" (=>eth1), "eth2addr", ... | |
c609719b | 2217 | |
2729af9d WD |
2218 | If the network interface stores some valid MAC address (for instance |
2219 | in SROM), this is used as default address if there is NO correspon- | |
2220 | ding setting in the environment; if the corresponding environment | |
2221 | variable is set, this overrides the settings in the card; that means: | |
c609719b | 2222 | |
2729af9d WD |
2223 | o If the SROM has a valid MAC address, and there is no address in the |
2224 | environment, the SROM's address is used. | |
c609719b | 2225 | |
2729af9d WD |
2226 | o If there is no valid address in the SROM, and a definition in the |
2227 | environment exists, then the value from the environment variable is | |
2228 | used. | |
c609719b | 2229 | |
2729af9d WD |
2230 | o If both the SROM and the environment contain a MAC address, and |
2231 | both addresses are the same, this MAC address is used. | |
c609719b | 2232 | |
2729af9d WD |
2233 | o If both the SROM and the environment contain a MAC address, and the |
2234 | addresses differ, the value from the environment is used and a | |
2235 | warning is printed. | |
c609719b | 2236 | |
2729af9d | 2237 | o If neither SROM nor the environment contain a MAC address, an error |
bef1014b JH |
2238 | is raised. If CONFIG_NET_RANDOM_ETHADDR is defined, then in this case |
2239 | a random, locally-assigned MAC is used. | |
c609719b | 2240 | |
ecee9324 | 2241 | If Ethernet drivers implement the 'write_hwaddr' function, valid MAC addresses |
c0f40859 | 2242 | will be programmed into hardware as part of the initialization process. This |
ecee9324 BW |
2243 | may be skipped by setting the appropriate 'ethmacskip' environment variable. |
2244 | The naming convention is as follows: | |
2245 | "ethmacskip" (=>eth0), "eth1macskip" (=>eth1) etc. | |
c609719b | 2246 | |
2729af9d WD |
2247 | Image Formats: |
2248 | ============== | |
c609719b | 2249 | |
3310c549 MB |
2250 | U-Boot is capable of booting (and performing other auxiliary operations on) |
2251 | images in two formats: | |
2252 | ||
2253 | New uImage format (FIT) | |
2254 | ----------------------- | |
2255 | ||
2256 | Flexible and powerful format based on Flattened Image Tree -- FIT (similar | |
2257 | to Flattened Device Tree). It allows the use of images with multiple | |
2258 | components (several kernels, ramdisks, etc.), with contents protected by | |
2259 | SHA1, MD5 or CRC32. More details are found in the doc/uImage.FIT directory. | |
2260 | ||
2261 | ||
2262 | Old uImage format | |
2263 | ----------------- | |
2264 | ||
2265 | Old image format is based on binary files which can be basically anything, | |
2266 | preceded by a special header; see the definitions in include/image.h for | |
2267 | details; basically, the header defines the following image properties: | |
c609719b | 2268 | |
2729af9d WD |
2269 | * Target Operating System (Provisions for OpenBSD, NetBSD, FreeBSD, |
2270 | 4.4BSD, Linux, SVR4, Esix, Solaris, Irix, SCO, Dell, NCR, VxWorks, | |
f5ed9e39 | 2271 | LynxOS, pSOS, QNX, RTEMS, INTEGRITY; |
0797e736 | 2272 | Currently supported: Linux, NetBSD, VxWorks, QNX, RTEMS, INTEGRITY). |
daab59ac | 2273 | * Target CPU Architecture (Provisions for Alpha, ARM, Intel x86, |
11232139 TR |
2274 | IA64, MIPS, Nios II, PowerPC, IBM S390, SuperH, Sparc, Sparc 64 Bit; |
2275 | Currently supported: ARM, Intel x86, MIPS, Nios II, PowerPC). | |
2729af9d WD |
2276 | * Compression Type (uncompressed, gzip, bzip2) |
2277 | * Load Address | |
2278 | * Entry Point | |
2279 | * Image Name | |
2280 | * Image Timestamp | |
c609719b | 2281 | |
2729af9d WD |
2282 | The header is marked by a special Magic Number, and both the header |
2283 | and the data portions of the image are secured against corruption by | |
2284 | CRC32 checksums. | |
c609719b WD |
2285 | |
2286 | ||
2729af9d WD |
2287 | Linux Support: |
2288 | ============== | |
c609719b | 2289 | |
2729af9d WD |
2290 | Although U-Boot should support any OS or standalone application |
2291 | easily, the main focus has always been on Linux during the design of | |
2292 | U-Boot. | |
c609719b | 2293 | |
2729af9d WD |
2294 | U-Boot includes many features that so far have been part of some |
2295 | special "boot loader" code within the Linux kernel. Also, any | |
2296 | "initrd" images to be used are no longer part of one big Linux image; | |
2297 | instead, kernel and "initrd" are separate images. This implementation | |
2298 | serves several purposes: | |
c609719b | 2299 | |
2729af9d WD |
2300 | - the same features can be used for other OS or standalone |
2301 | applications (for instance: using compressed images to reduce the | |
2302 | Flash memory footprint) | |
c609719b | 2303 | |
2729af9d WD |
2304 | - it becomes much easier to port new Linux kernel versions because |
2305 | lots of low-level, hardware dependent stuff are done by U-Boot | |
c609719b | 2306 | |
2729af9d WD |
2307 | - the same Linux kernel image can now be used with different "initrd" |
2308 | images; of course this also means that different kernel images can | |
2309 | be run with the same "initrd". This makes testing easier (you don't | |
2310 | have to build a new "zImage.initrd" Linux image when you just | |
2311 | change a file in your "initrd"). Also, a field-upgrade of the | |
2312 | software is easier now. | |
c609719b | 2313 | |
c609719b | 2314 | |
2729af9d WD |
2315 | Linux HOWTO: |
2316 | ============ | |
c609719b | 2317 | |
2729af9d WD |
2318 | Porting Linux to U-Boot based systems: |
2319 | --------------------------------------- | |
c609719b | 2320 | |
2729af9d WD |
2321 | U-Boot cannot save you from doing all the necessary modifications to |
2322 | configure the Linux device drivers for use with your target hardware | |
2323 | (no, we don't intend to provide a full virtual machine interface to | |
2324 | Linux :-). | |
c609719b | 2325 | |
a47a12be | 2326 | But now you can ignore ALL boot loader code (in arch/powerpc/mbxboot). |
24ee89b9 | 2327 | |
2729af9d WD |
2328 | Just make sure your machine specific header file (for instance |
2329 | include/asm-ppc/tqm8xx.h) includes the same definition of the Board | |
1dc30693 MH |
2330 | Information structure as we define in include/asm-<arch>/u-boot.h, |
2331 | and make sure that your definition of IMAP_ADDR uses the same value | |
6d0f6bcf | 2332 | as your U-Boot configuration in CONFIG_SYS_IMMR. |
24ee89b9 | 2333 | |
2eb31b13 SG |
2334 | Note that U-Boot now has a driver model, a unified model for drivers. |
2335 | If you are adding a new driver, plumb it into driver model. If there | |
2336 | is no uclass available, you are encouraged to create one. See | |
2337 | doc/driver-model. | |
2338 | ||
c609719b | 2339 | |
2729af9d WD |
2340 | Configuring the Linux kernel: |
2341 | ----------------------------- | |
c609719b | 2342 | |
2729af9d WD |
2343 | No specific requirements for U-Boot. Make sure you have some root |
2344 | device (initial ramdisk, NFS) for your target system. | |
2345 | ||
2346 | ||
2347 | Building a Linux Image: | |
2348 | ----------------------- | |
c609719b | 2349 | |
2729af9d WD |
2350 | With U-Boot, "normal" build targets like "zImage" or "bzImage" are |
2351 | not used. If you use recent kernel source, a new build target | |
2352 | "uImage" will exist which automatically builds an image usable by | |
2353 | U-Boot. Most older kernels also have support for a "pImage" target, | |
2354 | which was introduced for our predecessor project PPCBoot and uses a | |
2355 | 100% compatible format. | |
2356 | ||
2357 | Example: | |
2358 | ||
ab584d67 | 2359 | make TQM850L_defconfig |
2729af9d WD |
2360 | make oldconfig |
2361 | make dep | |
2362 | make uImage | |
2363 | ||
2364 | The "uImage" build target uses a special tool (in 'tools/mkimage') to | |
2365 | encapsulate a compressed Linux kernel image with header information, | |
2366 | CRC32 checksum etc. for use with U-Boot. This is what we are doing: | |
2367 | ||
2368 | * build a standard "vmlinux" kernel image (in ELF binary format): | |
2369 | ||
2370 | * convert the kernel into a raw binary image: | |
2371 | ||
2372 | ${CROSS_COMPILE}-objcopy -O binary \ | |
2373 | -R .note -R .comment \ | |
2374 | -S vmlinux linux.bin | |
2375 | ||
2376 | * compress the binary image: | |
2377 | ||
2378 | gzip -9 linux.bin | |
2379 | ||
2380 | * package compressed binary image for U-Boot: | |
2381 | ||
2382 | mkimage -A ppc -O linux -T kernel -C gzip \ | |
2383 | -a 0 -e 0 -n "Linux Kernel Image" \ | |
2384 | -d linux.bin.gz uImage | |
c609719b | 2385 | |
c609719b | 2386 | |
2729af9d WD |
2387 | The "mkimage" tool can also be used to create ramdisk images for use |
2388 | with U-Boot, either separated from the Linux kernel image, or | |
2389 | combined into one file. "mkimage" encapsulates the images with a 64 | |
2390 | byte header containing information about target architecture, | |
2391 | operating system, image type, compression method, entry points, time | |
2392 | stamp, CRC32 checksums, etc. | |
2393 | ||
2394 | "mkimage" can be called in two ways: to verify existing images and | |
2395 | print the header information, or to build new images. | |
2396 | ||
2397 | In the first form (with "-l" option) mkimage lists the information | |
2398 | contained in the header of an existing U-Boot image; this includes | |
2399 | checksum verification: | |
c609719b | 2400 | |
2729af9d WD |
2401 | tools/mkimage -l image |
2402 | -l ==> list image header information | |
2403 | ||
2404 | The second form (with "-d" option) is used to build a U-Boot image | |
2405 | from a "data file" which is used as image payload: | |
2406 | ||
2407 | tools/mkimage -A arch -O os -T type -C comp -a addr -e ep \ | |
2408 | -n name -d data_file image | |
2409 | -A ==> set architecture to 'arch' | |
2410 | -O ==> set operating system to 'os' | |
2411 | -T ==> set image type to 'type' | |
2412 | -C ==> set compression type 'comp' | |
2413 | -a ==> set load address to 'addr' (hex) | |
2414 | -e ==> set entry point to 'ep' (hex) | |
2415 | -n ==> set image name to 'name' | |
2416 | -d ==> use image data from 'datafile' | |
2417 | ||
69459791 WD |
2418 | Right now, all Linux kernels for PowerPC systems use the same load |
2419 | address (0x00000000), but the entry point address depends on the | |
2420 | kernel version: | |
2729af9d WD |
2421 | |
2422 | - 2.2.x kernels have the entry point at 0x0000000C, | |
2423 | - 2.3.x and later kernels have the entry point at 0x00000000. | |
2424 | ||
2425 | So a typical call to build a U-Boot image would read: | |
2426 | ||
2427 | -> tools/mkimage -n '2.4.4 kernel for TQM850L' \ | |
2428 | > -A ppc -O linux -T kernel -C gzip -a 0 -e 0 \ | |
a47a12be | 2429 | > -d /opt/elsk/ppc_8xx/usr/src/linux-2.4.4/arch/powerpc/coffboot/vmlinux.gz \ |
2729af9d WD |
2430 | > examples/uImage.TQM850L |
2431 | Image Name: 2.4.4 kernel for TQM850L | |
2432 | Created: Wed Jul 19 02:34:59 2000 | |
2433 | Image Type: PowerPC Linux Kernel Image (gzip compressed) | |
2434 | Data Size: 335725 Bytes = 327.86 kB = 0.32 MB | |
2435 | Load Address: 0x00000000 | |
2436 | Entry Point: 0x00000000 | |
2437 | ||
2438 | To verify the contents of the image (or check for corruption): | |
2439 | ||
2440 | -> tools/mkimage -l examples/uImage.TQM850L | |
2441 | Image Name: 2.4.4 kernel for TQM850L | |
2442 | Created: Wed Jul 19 02:34:59 2000 | |
2443 | Image Type: PowerPC Linux Kernel Image (gzip compressed) | |
2444 | Data Size: 335725 Bytes = 327.86 kB = 0.32 MB | |
2445 | Load Address: 0x00000000 | |
2446 | Entry Point: 0x00000000 | |
2447 | ||
2448 | NOTE: for embedded systems where boot time is critical you can trade | |
2449 | speed for memory and install an UNCOMPRESSED image instead: this | |
2450 | needs more space in Flash, but boots much faster since it does not | |
2451 | need to be uncompressed: | |
2452 | ||
a47a12be | 2453 | -> gunzip /opt/elsk/ppc_8xx/usr/src/linux-2.4.4/arch/powerpc/coffboot/vmlinux.gz |
2729af9d WD |
2454 | -> tools/mkimage -n '2.4.4 kernel for TQM850L' \ |
2455 | > -A ppc -O linux -T kernel -C none -a 0 -e 0 \ | |
a47a12be | 2456 | > -d /opt/elsk/ppc_8xx/usr/src/linux-2.4.4/arch/powerpc/coffboot/vmlinux \ |
2729af9d WD |
2457 | > examples/uImage.TQM850L-uncompressed |
2458 | Image Name: 2.4.4 kernel for TQM850L | |
2459 | Created: Wed Jul 19 02:34:59 2000 | |
2460 | Image Type: PowerPC Linux Kernel Image (uncompressed) | |
2461 | Data Size: 792160 Bytes = 773.59 kB = 0.76 MB | |
2462 | Load Address: 0x00000000 | |
2463 | Entry Point: 0x00000000 | |
2464 | ||
2465 | ||
2466 | Similar you can build U-Boot images from a 'ramdisk.image.gz' file | |
2467 | when your kernel is intended to use an initial ramdisk: | |
2468 | ||
2469 | -> tools/mkimage -n 'Simple Ramdisk Image' \ | |
2470 | > -A ppc -O linux -T ramdisk -C gzip \ | |
2471 | > -d /LinuxPPC/images/SIMPLE-ramdisk.image.gz examples/simple-initrd | |
2472 | Image Name: Simple Ramdisk Image | |
2473 | Created: Wed Jan 12 14:01:50 2000 | |
2474 | Image Type: PowerPC Linux RAMDisk Image (gzip compressed) | |
2475 | Data Size: 566530 Bytes = 553.25 kB = 0.54 MB | |
2476 | Load Address: 0x00000000 | |
2477 | Entry Point: 0x00000000 | |
2478 | ||
e157a111 TH |
2479 | The "dumpimage" tool can be used to disassemble or list the contents of images |
2480 | built by mkimage. See dumpimage's help output (-h) for details. | |
2729af9d WD |
2481 | |
2482 | Installing a Linux Image: | |
2483 | ------------------------- | |
2484 | ||
2485 | To downloading a U-Boot image over the serial (console) interface, | |
2486 | you must convert the image to S-Record format: | |
2487 | ||
2488 | objcopy -I binary -O srec examples/image examples/image.srec | |
2489 | ||
2490 | The 'objcopy' does not understand the information in the U-Boot | |
2491 | image header, so the resulting S-Record file will be relative to | |
2492 | address 0x00000000. To load it to a given address, you need to | |
2493 | specify the target address as 'offset' parameter with the 'loads' | |
2494 | command. | |
2495 | ||
2496 | Example: install the image to address 0x40100000 (which on the | |
2497 | TQM8xxL is in the first Flash bank): | |
2498 | ||
2499 | => erase 40100000 401FFFFF | |
2500 | ||
2501 | .......... done | |
2502 | Erased 8 sectors | |
2503 | ||
2504 | => loads 40100000 | |
2505 | ## Ready for S-Record download ... | |
2506 | ~>examples/image.srec | |
2507 | 1 2 3 4 5 6 7 8 9 10 11 12 13 ... | |
2508 | ... | |
2509 | 15989 15990 15991 15992 | |
2510 | [file transfer complete] | |
2511 | [connected] | |
2512 | ## Start Addr = 0x00000000 | |
2513 | ||
2514 | ||
2515 | You can check the success of the download using the 'iminfo' command; | |
218ca724 | 2516 | this includes a checksum verification so you can be sure no data |
2729af9d WD |
2517 | corruption happened: |
2518 | ||
2519 | => imi 40100000 | |
2520 | ||
2521 | ## Checking Image at 40100000 ... | |
2522 | Image Name: 2.2.13 for initrd on TQM850L | |
2523 | Image Type: PowerPC Linux Kernel Image (gzip compressed) | |
2524 | Data Size: 335725 Bytes = 327 kB = 0 MB | |
2525 | Load Address: 00000000 | |
2526 | Entry Point: 0000000c | |
2527 | Verifying Checksum ... OK | |
2528 | ||
2529 | ||
2530 | Boot Linux: | |
2531 | ----------- | |
2532 | ||
2533 | The "bootm" command is used to boot an application that is stored in | |
2534 | memory (RAM or Flash). In case of a Linux kernel image, the contents | |
2535 | of the "bootargs" environment variable is passed to the kernel as | |
2536 | parameters. You can check and modify this variable using the | |
2537 | "printenv" and "setenv" commands: | |
2538 | ||
2539 | ||
2540 | => printenv bootargs | |
2541 | bootargs=root=/dev/ram | |
2542 | ||
2543 | => setenv bootargs root=/dev/nfs rw nfsroot=10.0.0.2:/LinuxPPC nfsaddrs=10.0.0.99:10.0.0.2 | |
2544 | ||
2545 | => printenv bootargs | |
2546 | bootargs=root=/dev/nfs rw nfsroot=10.0.0.2:/LinuxPPC nfsaddrs=10.0.0.99:10.0.0.2 | |
2547 | ||
2548 | => bootm 40020000 | |
2549 | ## Booting Linux kernel at 40020000 ... | |
2550 | Image Name: 2.2.13 for NFS on TQM850L | |
2551 | Image Type: PowerPC Linux Kernel Image (gzip compressed) | |
2552 | Data Size: 381681 Bytes = 372 kB = 0 MB | |
2553 | Load Address: 00000000 | |
2554 | Entry Point: 0000000c | |
2555 | Verifying Checksum ... OK | |
2556 | Uncompressing Kernel Image ... OK | |
2557 | Linux version 2.2.13 (wd@denx.local.net) (gcc version 2.95.2 19991024 (release)) #1 Wed Jul 19 02:35:17 MEST 2000 | |
2558 | Boot arguments: root=/dev/nfs rw nfsroot=10.0.0.2:/LinuxPPC nfsaddrs=10.0.0.99:10.0.0.2 | |
2559 | time_init: decrementer frequency = 187500000/60 | |
2560 | Calibrating delay loop... 49.77 BogoMIPS | |
2561 | Memory: 15208k available (700k kernel code, 444k data, 32k init) [c0000000,c1000000] | |
2562 | ... | |
2563 | ||
11ccc33f | 2564 | If you want to boot a Linux kernel with initial RAM disk, you pass |
2729af9d WD |
2565 | the memory addresses of both the kernel and the initrd image (PPBCOOT |
2566 | format!) to the "bootm" command: | |
2567 | ||
2568 | => imi 40100000 40200000 | |
2569 | ||
2570 | ## Checking Image at 40100000 ... | |
2571 | Image Name: 2.2.13 for initrd on TQM850L | |
2572 | Image Type: PowerPC Linux Kernel Image (gzip compressed) | |
2573 | Data Size: 335725 Bytes = 327 kB = 0 MB | |
2574 | Load Address: 00000000 | |
2575 | Entry Point: 0000000c | |
2576 | Verifying Checksum ... OK | |
2577 | ||
2578 | ## Checking Image at 40200000 ... | |
2579 | Image Name: Simple Ramdisk Image | |
2580 | Image Type: PowerPC Linux RAMDisk Image (gzip compressed) | |
2581 | Data Size: 566530 Bytes = 553 kB = 0 MB | |
2582 | Load Address: 00000000 | |
2583 | Entry Point: 00000000 | |
2584 | Verifying Checksum ... OK | |
2585 | ||
2586 | => bootm 40100000 40200000 | |
2587 | ## Booting Linux kernel at 40100000 ... | |
2588 | Image Name: 2.2.13 for initrd on TQM850L | |
2589 | Image Type: PowerPC Linux Kernel Image (gzip compressed) | |
2590 | Data Size: 335725 Bytes = 327 kB = 0 MB | |
2591 | Load Address: 00000000 | |
2592 | Entry Point: 0000000c | |
2593 | Verifying Checksum ... OK | |
2594 | Uncompressing Kernel Image ... OK | |
2595 | ## Loading RAMDisk Image at 40200000 ... | |
2596 | Image Name: Simple Ramdisk Image | |
2597 | Image Type: PowerPC Linux RAMDisk Image (gzip compressed) | |
2598 | Data Size: 566530 Bytes = 553 kB = 0 MB | |
2599 | Load Address: 00000000 | |
2600 | Entry Point: 00000000 | |
2601 | Verifying Checksum ... OK | |
2602 | Loading Ramdisk ... OK | |
2603 | Linux version 2.2.13 (wd@denx.local.net) (gcc version 2.95.2 19991024 (release)) #1 Wed Jul 19 02:32:08 MEST 2000 | |
2604 | Boot arguments: root=/dev/ram | |
2605 | time_init: decrementer frequency = 187500000/60 | |
2606 | Calibrating delay loop... 49.77 BogoMIPS | |
2607 | ... | |
2608 | RAMDISK: Compressed image found at block 0 | |
2609 | VFS: Mounted root (ext2 filesystem). | |
2610 | ||
2611 | bash# | |
2612 | ||
0267768e MM |
2613 | Boot Linux and pass a flat device tree: |
2614 | ----------- | |
2615 | ||
2616 | First, U-Boot must be compiled with the appropriate defines. See the section | |
2617 | titled "Linux Kernel Interface" above for a more in depth explanation. The | |
2618 | following is an example of how to start a kernel and pass an updated | |
2619 | flat device tree: | |
2620 | ||
2621 | => print oftaddr | |
2622 | oftaddr=0x300000 | |
2623 | => print oft | |
2624 | oft=oftrees/mpc8540ads.dtb | |
2625 | => tftp $oftaddr $oft | |
2626 | Speed: 1000, full duplex | |
2627 | Using TSEC0 device | |
2628 | TFTP from server 192.168.1.1; our IP address is 192.168.1.101 | |
2629 | Filename 'oftrees/mpc8540ads.dtb'. | |
2630 | Load address: 0x300000 | |
2631 | Loading: # | |
2632 | done | |
2633 | Bytes transferred = 4106 (100a hex) | |
2634 | => tftp $loadaddr $bootfile | |
2635 | Speed: 1000, full duplex | |
2636 | Using TSEC0 device | |
2637 | TFTP from server 192.168.1.1; our IP address is 192.168.1.2 | |
2638 | Filename 'uImage'. | |
2639 | Load address: 0x200000 | |
2640 | Loading:############ | |
2641 | done | |
2642 | Bytes transferred = 1029407 (fb51f hex) | |
2643 | => print loadaddr | |
2644 | loadaddr=200000 | |
2645 | => print oftaddr | |
2646 | oftaddr=0x300000 | |
2647 | => bootm $loadaddr - $oftaddr | |
2648 | ## Booting image at 00200000 ... | |
a9398e01 WD |
2649 | Image Name: Linux-2.6.17-dirty |
2650 | Image Type: PowerPC Linux Kernel Image (gzip compressed) | |
2651 | Data Size: 1029343 Bytes = 1005.2 kB | |
0267768e | 2652 | Load Address: 00000000 |
a9398e01 | 2653 | Entry Point: 00000000 |
0267768e MM |
2654 | Verifying Checksum ... OK |
2655 | Uncompressing Kernel Image ... OK | |
2656 | Booting using flat device tree at 0x300000 | |
2657 | Using MPC85xx ADS machine description | |
2658 | Memory CAM mapping: CAM0=256Mb, CAM1=256Mb, CAM2=0Mb residual: 0Mb | |
2659 | [snip] | |
2660 | ||
2661 | ||
2729af9d WD |
2662 | More About U-Boot Image Types: |
2663 | ------------------------------ | |
2664 | ||
2665 | U-Boot supports the following image types: | |
2666 | ||
2667 | "Standalone Programs" are directly runnable in the environment | |
2668 | provided by U-Boot; it is expected that (if they behave | |
2669 | well) you can continue to work in U-Boot after return from | |
2670 | the Standalone Program. | |
2671 | "OS Kernel Images" are usually images of some Embedded OS which | |
2672 | will take over control completely. Usually these programs | |
2673 | will install their own set of exception handlers, device | |
2674 | drivers, set up the MMU, etc. - this means, that you cannot | |
2675 | expect to re-enter U-Boot except by resetting the CPU. | |
2676 | "RAMDisk Images" are more or less just data blocks, and their | |
2677 | parameters (address, size) are passed to an OS kernel that is | |
2678 | being started. | |
2679 | "Multi-File Images" contain several images, typically an OS | |
2680 | (Linux) kernel image and one or more data images like | |
2681 | RAMDisks. This construct is useful for instance when you want | |
2682 | to boot over the network using BOOTP etc., where the boot | |
2683 | server provides just a single image file, but you want to get | |
2684 | for instance an OS kernel and a RAMDisk image. | |
2685 | ||
2686 | "Multi-File Images" start with a list of image sizes, each | |
2687 | image size (in bytes) specified by an "uint32_t" in network | |
2688 | byte order. This list is terminated by an "(uint32_t)0". | |
2689 | Immediately after the terminating 0 follow the images, one by | |
2690 | one, all aligned on "uint32_t" boundaries (size rounded up to | |
2691 | a multiple of 4 bytes). | |
2692 | ||
2693 | "Firmware Images" are binary images containing firmware (like | |
2694 | U-Boot or FPGA images) which usually will be programmed to | |
2695 | flash memory. | |
2696 | ||
2697 | "Script files" are command sequences that will be executed by | |
2698 | U-Boot's command interpreter; this feature is especially | |
2699 | useful when you configure U-Boot to use a real shell (hush) | |
2700 | as command interpreter. | |
2701 | ||
44f074c7 MV |
2702 | Booting the Linux zImage: |
2703 | ------------------------- | |
2704 | ||
2705 | On some platforms, it's possible to boot Linux zImage. This is done | |
2706 | using the "bootz" command. The syntax of "bootz" command is the same | |
2707 | as the syntax of "bootm" command. | |
2708 | ||
8ac28563 | 2709 | Note, defining the CONFIG_SUPPORT_RAW_INITRD allows user to supply |
017e1f3f MV |
2710 | kernel with raw initrd images. The syntax is slightly different, the |
2711 | address of the initrd must be augmented by it's size, in the following | |
2712 | format: "<initrd addres>:<initrd size>". | |
2713 | ||
2729af9d WD |
2714 | |
2715 | Standalone HOWTO: | |
2716 | ================= | |
2717 | ||
2718 | One of the features of U-Boot is that you can dynamically load and | |
2719 | run "standalone" applications, which can use some resources of | |
2720 | U-Boot like console I/O functions or interrupt services. | |
2721 | ||
2722 | Two simple examples are included with the sources: | |
2723 | ||
2724 | "Hello World" Demo: | |
2725 | ------------------- | |
2726 | ||
2727 | 'examples/hello_world.c' contains a small "Hello World" Demo | |
2728 | application; it is automatically compiled when you build U-Boot. | |
2729 | It's configured to run at address 0x00040004, so you can play with it | |
2730 | like that: | |
2731 | ||
2732 | => loads | |
2733 | ## Ready for S-Record download ... | |
2734 | ~>examples/hello_world.srec | |
2735 | 1 2 3 4 5 6 7 8 9 10 11 ... | |
2736 | [file transfer complete] | |
2737 | [connected] | |
2738 | ## Start Addr = 0x00040004 | |
2739 | ||
2740 | => go 40004 Hello World! This is a test. | |
2741 | ## Starting application at 0x00040004 ... | |
2742 | Hello World | |
2743 | argc = 7 | |
2744 | argv[0] = "40004" | |
2745 | argv[1] = "Hello" | |
2746 | argv[2] = "World!" | |
2747 | argv[3] = "This" | |
2748 | argv[4] = "is" | |
2749 | argv[5] = "a" | |
2750 | argv[6] = "test." | |
2751 | argv[7] = "<NULL>" | |
2752 | Hit any key to exit ... | |
2753 | ||
2754 | ## Application terminated, rc = 0x0 | |
2755 | ||
2756 | Another example, which demonstrates how to register a CPM interrupt | |
2757 | handler with the U-Boot code, can be found in 'examples/timer.c'. | |
2758 | Here, a CPM timer is set up to generate an interrupt every second. | |
2759 | The interrupt service routine is trivial, just printing a '.' | |
2760 | character, but this is just a demo program. The application can be | |
2761 | controlled by the following keys: | |
2762 | ||
2763 | ? - print current values og the CPM Timer registers | |
2764 | b - enable interrupts and start timer | |
2765 | e - stop timer and disable interrupts | |
2766 | q - quit application | |
2767 | ||
2768 | => loads | |
2769 | ## Ready for S-Record download ... | |
2770 | ~>examples/timer.srec | |
2771 | 1 2 3 4 5 6 7 8 9 10 11 ... | |
2772 | [file transfer complete] | |
2773 | [connected] | |
2774 | ## Start Addr = 0x00040004 | |
2775 | ||
2776 | => go 40004 | |
2777 | ## Starting application at 0x00040004 ... | |
2778 | TIMERS=0xfff00980 | |
2779 | Using timer 1 | |
2780 | tgcr @ 0xfff00980, tmr @ 0xfff00990, trr @ 0xfff00994, tcr @ 0xfff00998, tcn @ 0xfff0099c, ter @ 0xfff009b0 | |
2781 | ||
2782 | Hit 'b': | |
2783 | [q, b, e, ?] Set interval 1000000 us | |
2784 | Enabling timer | |
2785 | Hit '?': | |
2786 | [q, b, e, ?] ........ | |
2787 | tgcr=0x1, tmr=0xff1c, trr=0x3d09, tcr=0x0, tcn=0xef6, ter=0x0 | |
2788 | Hit '?': | |
2789 | [q, b, e, ?] . | |
2790 | tgcr=0x1, tmr=0xff1c, trr=0x3d09, tcr=0x0, tcn=0x2ad4, ter=0x0 | |
2791 | Hit '?': | |
2792 | [q, b, e, ?] . | |
2793 | tgcr=0x1, tmr=0xff1c, trr=0x3d09, tcr=0x0, tcn=0x1efc, ter=0x0 | |
2794 | Hit '?': | |
2795 | [q, b, e, ?] . | |
2796 | tgcr=0x1, tmr=0xff1c, trr=0x3d09, tcr=0x0, tcn=0x169d, ter=0x0 | |
2797 | Hit 'e': | |
2798 | [q, b, e, ?] ...Stopping timer | |
2799 | Hit 'q': | |
2800 | [q, b, e, ?] ## Application terminated, rc = 0x0 | |
2801 | ||
2802 | ||
2803 | Minicom warning: | |
2804 | ================ | |
2805 | ||
2806 | Over time, many people have reported problems when trying to use the | |
2807 | "minicom" terminal emulation program for serial download. I (wd) | |
2808 | consider minicom to be broken, and recommend not to use it. Under | |
2809 | Unix, I recommend to use C-Kermit for general purpose use (and | |
2810 | especially for kermit binary protocol download ("loadb" command), and | |
e53515a2 | 2811 | use "cu" for S-Record download ("loads" command). See |
047f6ec0 | 2812 | https://www.denx.de/wiki/view/DULG/SystemSetup#Section_4.3. |
e53515a2 KP |
2813 | for help with kermit. |
2814 | ||
2729af9d WD |
2815 | |
2816 | Nevertheless, if you absolutely want to use it try adding this | |
2817 | configuration to your "File transfer protocols" section: | |
2818 | ||
2819 | Name Program Name U/D FullScr IO-Red. Multi | |
2820 | X kermit /usr/bin/kermit -i -l %l -s Y U Y N N | |
2821 | Y kermit /usr/bin/kermit -i -l %l -r N D Y N N | |
2822 | ||
2823 | ||
2824 | NetBSD Notes: | |
2825 | ============= | |
2826 | ||
2827 | Starting at version 0.9.2, U-Boot supports NetBSD both as host | |
2828 | (build U-Boot) and target system (boots NetBSD/mpc8xx). | |
2829 | ||
2830 | Building requires a cross environment; it is known to work on | |
2831 | NetBSD/i386 with the cross-powerpc-netbsd-1.3 package (you will also | |
2832 | need gmake since the Makefiles are not compatible with BSD make). | |
2833 | Note that the cross-powerpc package does not install include files; | |
2834 | attempting to build U-Boot will fail because <machine/ansi.h> is | |
2835 | missing. This file has to be installed and patched manually: | |
2836 | ||
2837 | # cd /usr/pkg/cross/powerpc-netbsd/include | |
2838 | # mkdir powerpc | |
2839 | # ln -s powerpc machine | |
2840 | # cp /usr/src/sys/arch/powerpc/include/ansi.h powerpc/ansi.h | |
2841 | # ${EDIT} powerpc/ansi.h ## must remove __va_list, _BSD_VA_LIST | |
2842 | ||
2843 | Native builds *don't* work due to incompatibilities between native | |
2844 | and U-Boot include files. | |
2845 | ||
2846 | Booting assumes that (the first part of) the image booted is a | |
2847 | stage-2 loader which in turn loads and then invokes the kernel | |
2848 | proper. Loader sources will eventually appear in the NetBSD source | |
2849 | tree (probably in sys/arc/mpc8xx/stand/u-boot_stage2/); in the | |
2a8af187 | 2850 | meantime, see ftp://ftp.denx.de/pub/u-boot/ppcboot_stage2.tar.gz |
2729af9d WD |
2851 | |
2852 | ||
2853 | Implementation Internals: | |
2854 | ========================= | |
2855 | ||
2856 | The following is not intended to be a complete description of every | |
2857 | implementation detail. However, it should help to understand the | |
2858 | inner workings of U-Boot and make it easier to port it to custom | |
2859 | hardware. | |
2860 | ||
2861 | ||
2862 | Initial Stack, Global Data: | |
2863 | --------------------------- | |
2864 | ||
2865 | The implementation of U-Boot is complicated by the fact that U-Boot | |
2866 | starts running out of ROM (flash memory), usually without access to | |
2867 | system RAM (because the memory controller is not initialized yet). | |
2868 | This means that we don't have writable Data or BSS segments, and BSS | |
2869 | is not initialized as zero. To be able to get a C environment working | |
2870 | at all, we have to allocate at least a minimal stack. Implementation | |
2871 | options for this are defined and restricted by the CPU used: Some CPU | |
2872 | models provide on-chip memory (like the IMMR area on MPC8xx and | |
2873 | MPC826x processors), on others (parts of) the data cache can be | |
2874 | locked as (mis-) used as memory, etc. | |
2875 | ||
218ca724 | 2876 | Chris Hallinan posted a good summary of these issues to the |
0668236b | 2877 | U-Boot mailing list: |
2729af9d WD |
2878 | |
2879 | Subject: RE: [U-Boot-Users] RE: More On Memory Bank x (nothingness)? | |
2880 | From: "Chris Hallinan" <clh@net1plus.com> | |
2881 | Date: Mon, 10 Feb 2003 16:43:46 -0500 (22:43 MET) | |
2882 | ... | |
2883 | ||
2884 | Correct me if I'm wrong, folks, but the way I understand it | |
2885 | is this: Using DCACHE as initial RAM for Stack, etc, does not | |
2886 | require any physical RAM backing up the cache. The cleverness | |
2887 | is that the cache is being used as a temporary supply of | |
2888 | necessary storage before the SDRAM controller is setup. It's | |
11ccc33f | 2889 | beyond the scope of this list to explain the details, but you |
2729af9d WD |
2890 | can see how this works by studying the cache architecture and |
2891 | operation in the architecture and processor-specific manuals. | |
2892 | ||
2893 | OCM is On Chip Memory, which I believe the 405GP has 4K. It | |
2894 | is another option for the system designer to use as an | |
11ccc33f | 2895 | initial stack/RAM area prior to SDRAM being available. Either |
2729af9d WD |
2896 | option should work for you. Using CS 4 should be fine if your |
2897 | board designers haven't used it for something that would | |
2898 | cause you grief during the initial boot! It is frequently not | |
2899 | used. | |
2900 | ||
6d0f6bcf | 2901 | CONFIG_SYS_INIT_RAM_ADDR should be somewhere that won't interfere |
2729af9d WD |
2902 | with your processor/board/system design. The default value |
2903 | you will find in any recent u-boot distribution in | |
8a316c9b | 2904 | walnut.h should work for you. I'd set it to a value larger |
2729af9d WD |
2905 | than your SDRAM module. If you have a 64MB SDRAM module, set |
2906 | it above 400_0000. Just make sure your board has no resources | |
2907 | that are supposed to respond to that address! That code in | |
2908 | start.S has been around a while and should work as is when | |
2909 | you get the config right. | |
2910 | ||
2911 | -Chris Hallinan | |
2912 | DS4.COM, Inc. | |
2913 | ||
2914 | It is essential to remember this, since it has some impact on the C | |
2915 | code for the initialization procedures: | |
2916 | ||
2917 | * Initialized global data (data segment) is read-only. Do not attempt | |
2918 | to write it. | |
2919 | ||
b445bbb4 | 2920 | * Do not use any uninitialized global data (or implicitly initialized |
2729af9d WD |
2921 | as zero data - BSS segment) at all - this is undefined, initiali- |
2922 | zation is performed later (when relocating to RAM). | |
2923 | ||
2924 | * Stack space is very limited. Avoid big data buffers or things like | |
2925 | that. | |
2926 | ||
2927 | Having only the stack as writable memory limits means we cannot use | |
b445bbb4 | 2928 | normal global data to share information between the code. But it |
2729af9d WD |
2929 | turned out that the implementation of U-Boot can be greatly |
2930 | simplified by making a global data structure (gd_t) available to all | |
2931 | functions. We could pass a pointer to this data as argument to _all_ | |
2932 | functions, but this would bloat the code. Instead we use a feature of | |
2933 | the GCC compiler (Global Register Variables) to share the data: we | |
2934 | place a pointer (gd) to the global data into a register which we | |
2935 | reserve for this purpose. | |
2936 | ||
2937 | When choosing a register for such a purpose we are restricted by the | |
2938 | relevant (E)ABI specifications for the current architecture, and by | |
2939 | GCC's implementation. | |
2940 | ||
2941 | For PowerPC, the following registers have specific use: | |
2942 | R1: stack pointer | |
e7670f6c | 2943 | R2: reserved for system use |
2729af9d WD |
2944 | R3-R4: parameter passing and return values |
2945 | R5-R10: parameter passing | |
2946 | R13: small data area pointer | |
2947 | R30: GOT pointer | |
2948 | R31: frame pointer | |
2949 | ||
e6bee808 JT |
2950 | (U-Boot also uses R12 as internal GOT pointer. r12 |
2951 | is a volatile register so r12 needs to be reset when | |
2952 | going back and forth between asm and C) | |
2729af9d | 2953 | |
e7670f6c | 2954 | ==> U-Boot will use R2 to hold a pointer to the global data |
2729af9d WD |
2955 | |
2956 | Note: on PPC, we could use a static initializer (since the | |
2957 | address of the global data structure is known at compile time), | |
2958 | but it turned out that reserving a register results in somewhat | |
2959 | smaller code - although the code savings are not that big (on | |
2960 | average for all boards 752 bytes for the whole U-Boot image, | |
2961 | 624 text + 127 data). | |
2962 | ||
2963 | On ARM, the following registers are used: | |
2964 | ||
2965 | R0: function argument word/integer result | |
2966 | R1-R3: function argument word | |
12eba1b4 JH |
2967 | R9: platform specific |
2968 | R10: stack limit (used only if stack checking is enabled) | |
2729af9d WD |
2969 | R11: argument (frame) pointer |
2970 | R12: temporary workspace | |
2971 | R13: stack pointer | |
2972 | R14: link register | |
2973 | R15: program counter | |
2974 | ||
12eba1b4 JH |
2975 | ==> U-Boot will use R9 to hold a pointer to the global data |
2976 | ||
2977 | Note: on ARM, only R_ARM_RELATIVE relocations are supported. | |
2729af9d | 2978 | |
0df01fd3 | 2979 | On Nios II, the ABI is documented here: |
047f6ec0 | 2980 | https://www.altera.com/literature/hb/nios2/n2cpu_nii51016.pdf |
0df01fd3 TC |
2981 | |
2982 | ==> U-Boot will use gp to hold a pointer to the global data | |
2983 | ||
2984 | Note: on Nios II, we give "-G0" option to gcc and don't use gp | |
2985 | to access small data sections, so gp is free. | |
2986 | ||
3fafced7 RC |
2987 | On RISC-V, the following registers are used: |
2988 | ||
2989 | x0: hard-wired zero (zero) | |
2990 | x1: return address (ra) | |
2991 | x2: stack pointer (sp) | |
2992 | x3: global pointer (gp) | |
2993 | x4: thread pointer (tp) | |
2994 | x5: link register (t0) | |
2995 | x8: frame pointer (fp) | |
2996 | x10-x11: arguments/return values (a0-1) | |
2997 | x12-x17: arguments (a2-7) | |
2998 | x28-31: temporaries (t3-6) | |
2999 | pc: program counter (pc) | |
3000 | ||
3001 | ==> U-Boot will use gp to hold a pointer to the global data | |
3002 | ||
2729af9d WD |
3003 | Memory Management: |
3004 | ------------------ | |
3005 | ||
3006 | U-Boot runs in system state and uses physical addresses, i.e. the | |
3007 | MMU is not used either for address mapping nor for memory protection. | |
3008 | ||
3009 | The available memory is mapped to fixed addresses using the memory | |
3010 | controller. In this process, a contiguous block is formed for each | |
3011 | memory type (Flash, SDRAM, SRAM), even when it consists of several | |
3012 | physical memory banks. | |
3013 | ||
3014 | U-Boot is installed in the first 128 kB of the first Flash bank (on | |
3015 | TQM8xxL modules this is the range 0x40000000 ... 0x4001FFFF). After | |
3016 | booting and sizing and initializing DRAM, the code relocates itself | |
3017 | to the upper end of DRAM. Immediately below the U-Boot code some | |
6d0f6bcf | 3018 | memory is reserved for use by malloc() [see CONFIG_SYS_MALLOC_LEN |
2729af9d WD |
3019 | configuration setting]. Below that, a structure with global Board |
3020 | Info data is placed, followed by the stack (growing downward). | |
3021 | ||
3022 | Additionally, some exception handler code is copied to the low 8 kB | |
3023 | of DRAM (0x00000000 ... 0x00001FFF). | |
3024 | ||
3025 | So a typical memory configuration with 16 MB of DRAM could look like | |
3026 | this: | |
3027 | ||
3028 | 0x0000 0000 Exception Vector code | |
3029 | : | |
3030 | 0x0000 1FFF | |
3031 | 0x0000 2000 Free for Application Use | |
3032 | : | |
3033 | : | |
3034 | ||
3035 | : | |
3036 | : | |
3037 | 0x00FB FF20 Monitor Stack (Growing downward) | |
3038 | 0x00FB FFAC Board Info Data and permanent copy of global data | |
3039 | 0x00FC 0000 Malloc Arena | |
3040 | : | |
3041 | 0x00FD FFFF | |
3042 | 0x00FE 0000 RAM Copy of Monitor Code | |
3043 | ... eventually: LCD or video framebuffer | |
3044 | ... eventually: pRAM (Protected RAM - unchanged by reset) | |
3045 | 0x00FF FFFF [End of RAM] | |
3046 | ||
3047 | ||
3048 | System Initialization: | |
3049 | ---------------------- | |
c609719b | 3050 | |
2729af9d | 3051 | In the reset configuration, U-Boot starts at the reset entry point |
11ccc33f | 3052 | (on most PowerPC systems at address 0x00000100). Because of the reset |
b445bbb4 | 3053 | configuration for CS0# this is a mirror of the on board Flash memory. |
2729af9d WD |
3054 | To be able to re-map memory U-Boot then jumps to its link address. |
3055 | To be able to implement the initialization code in C, a (small!) | |
3056 | initial stack is set up in the internal Dual Ported RAM (in case CPUs | |
2eb48ff7 HS |
3057 | which provide such a feature like), or in a locked part of the data |
3058 | cache. After that, U-Boot initializes the CPU core, the caches and | |
3059 | the SIU. | |
2729af9d WD |
3060 | |
3061 | Next, all (potentially) available memory banks are mapped using a | |
3062 | preliminary mapping. For example, we put them on 512 MB boundaries | |
3063 | (multiples of 0x20000000: SDRAM on 0x00000000 and 0x20000000, Flash | |
3064 | on 0x40000000 and 0x60000000, SRAM on 0x80000000). Then UPM A is | |
3065 | programmed for SDRAM access. Using the temporary configuration, a | |
3066 | simple memory test is run that determines the size of the SDRAM | |
3067 | banks. | |
3068 | ||
3069 | When there is more than one SDRAM bank, and the banks are of | |
3070 | different size, the largest is mapped first. For equal size, the first | |
3071 | bank (CS2#) is mapped first. The first mapping is always for address | |
3072 | 0x00000000, with any additional banks following immediately to create | |
3073 | contiguous memory starting from 0. | |
3074 | ||
3075 | Then, the monitor installs itself at the upper end of the SDRAM area | |
3076 | and allocates memory for use by malloc() and for the global Board | |
3077 | Info data; also, the exception vector code is copied to the low RAM | |
3078 | pages, and the final stack is set up. | |
3079 | ||
3080 | Only after this relocation will you have a "normal" C environment; | |
3081 | until that you are restricted in several ways, mostly because you are | |
3082 | running from ROM, and because the code will have to be relocated to a | |
3083 | new address in RAM. | |
3084 | ||
3085 | ||
3086 | U-Boot Porting Guide: | |
3087 | ---------------------- | |
c609719b | 3088 | |
2729af9d WD |
3089 | [Based on messages by Jerry Van Baren in the U-Boot-Users mailing |
3090 | list, October 2002] | |
c609719b WD |
3091 | |
3092 | ||
6c3fef28 | 3093 | int main(int argc, char *argv[]) |
2729af9d WD |
3094 | { |
3095 | sighandler_t no_more_time; | |
c609719b | 3096 | |
6c3fef28 JVB |
3097 | signal(SIGALRM, no_more_time); |
3098 | alarm(PROJECT_DEADLINE - toSec (3 * WEEK)); | |
c609719b | 3099 | |
2729af9d | 3100 | if (available_money > available_manpower) { |
6c3fef28 | 3101 | Pay consultant to port U-Boot; |
c609719b WD |
3102 | return 0; |
3103 | } | |
3104 | ||
2729af9d WD |
3105 | Download latest U-Boot source; |
3106 | ||
0668236b | 3107 | Subscribe to u-boot mailing list; |
2729af9d | 3108 | |
6c3fef28 JVB |
3109 | if (clueless) |
3110 | email("Hi, I am new to U-Boot, how do I get started?"); | |
2729af9d WD |
3111 | |
3112 | while (learning) { | |
3113 | Read the README file in the top level directory; | |
047f6ec0 | 3114 | Read https://www.denx.de/wiki/bin/view/DULG/Manual; |
24bcaec7 | 3115 | Read applicable doc/README.*; |
2729af9d | 3116 | Read the source, Luke; |
6c3fef28 | 3117 | /* find . -name "*.[chS]" | xargs grep -i <keyword> */ |
2729af9d WD |
3118 | } |
3119 | ||
6c3fef28 JVB |
3120 | if (available_money > toLocalCurrency ($2500)) |
3121 | Buy a BDI3000; | |
3122 | else | |
2729af9d | 3123 | Add a lot of aggravation and time; |
2729af9d | 3124 | |
6c3fef28 JVB |
3125 | if (a similar board exists) { /* hopefully... */ |
3126 | cp -a board/<similar> board/<myboard> | |
3127 | cp include/configs/<similar>.h include/configs/<myboard>.h | |
3128 | } else { | |
3129 | Create your own board support subdirectory; | |
3130 | Create your own board include/configs/<myboard>.h file; | |
3131 | } | |
3132 | Edit new board/<myboard> files | |
3133 | Edit new include/configs/<myboard>.h | |
3134 | ||
3135 | while (!accepted) { | |
3136 | while (!running) { | |
3137 | do { | |
3138 | Add / modify source code; | |
3139 | } until (compiles); | |
3140 | Debug; | |
3141 | if (clueless) | |
3142 | email("Hi, I am having problems..."); | |
3143 | } | |
3144 | Send patch file to the U-Boot email list; | |
3145 | if (reasonable critiques) | |
3146 | Incorporate improvements from email list code review; | |
3147 | else | |
3148 | Defend code as written; | |
2729af9d | 3149 | } |
2729af9d WD |
3150 | |
3151 | return 0; | |
3152 | } | |
3153 | ||
3154 | void no_more_time (int sig) | |
3155 | { | |
3156 | hire_a_guru(); | |
3157 | } | |
3158 | ||
c609719b | 3159 | |
2729af9d WD |
3160 | Coding Standards: |
3161 | ----------------- | |
c609719b | 3162 | |
2729af9d | 3163 | All contributions to U-Boot should conform to the Linux kernel |
659208da BS |
3164 | coding style; see the kernel coding style guide at |
3165 | https://www.kernel.org/doc/html/latest/process/coding-style.html, and the | |
3166 | script "scripts/Lindent" in your Linux kernel source directory. | |
2c051651 DZ |
3167 | |
3168 | Source files originating from a different project (for example the | |
3169 | MTD subsystem) are generally exempt from these guidelines and are not | |
b445bbb4 | 3170 | reformatted to ease subsequent migration to newer versions of those |
2c051651 DZ |
3171 | sources. |
3172 | ||
3173 | Please note that U-Boot is implemented in C (and to some small parts in | |
3174 | Assembler); no C++ is used, so please do not use C++ style comments (//) | |
3175 | in your code. | |
c609719b | 3176 | |
2729af9d WD |
3177 | Please also stick to the following formatting rules: |
3178 | - remove any trailing white space | |
7ca9296e | 3179 | - use TAB characters for indentation and vertical alignment, not spaces |
2729af9d | 3180 | - make sure NOT to use DOS '\r\n' line feeds |
7ca9296e | 3181 | - do not add more than 2 consecutive empty lines to source files |
2729af9d | 3182 | - do not add trailing empty lines to source files |
180d3f74 | 3183 | |
2729af9d WD |
3184 | Submissions which do not conform to the standards may be returned |
3185 | with a request to reformat the changes. | |
c609719b WD |
3186 | |
3187 | ||
2729af9d WD |
3188 | Submitting Patches: |
3189 | ------------------- | |
c609719b | 3190 | |
2729af9d WD |
3191 | Since the number of patches for U-Boot is growing, we need to |
3192 | establish some rules. Submissions which do not conform to these rules | |
3193 | may be rejected, even when they contain important and valuable stuff. | |
c609719b | 3194 | |
047f6ec0 | 3195 | Please see https://www.denx.de/wiki/U-Boot/Patches for details. |
218ca724 | 3196 | |
0668236b | 3197 | Patches shall be sent to the u-boot mailing list <u-boot@lists.denx.de>; |
1dade18e | 3198 | see https://lists.denx.de/listinfo/u-boot |
0668236b | 3199 | |
2729af9d WD |
3200 | When you send a patch, please include the following information with |
3201 | it: | |
c609719b | 3202 | |
2729af9d WD |
3203 | * For bug fixes: a description of the bug and how your patch fixes |
3204 | this bug. Please try to include a way of demonstrating that the | |
3205 | patch actually fixes something. | |
c609719b | 3206 | |
2729af9d WD |
3207 | * For new features: a description of the feature and your |
3208 | implementation. | |
c609719b | 3209 | |
7207b366 RD |
3210 | * For major contributions, add a MAINTAINERS file with your |
3211 | information and associated file and directory references. | |
c609719b | 3212 | |
27af930e AA |
3213 | * When you add support for a new board, don't forget to add a |
3214 | maintainer e-mail address to the boards.cfg file, too. | |
c609719b | 3215 | |
2729af9d WD |
3216 | * If your patch adds new configuration options, don't forget to |
3217 | document these in the README file. | |
c609719b | 3218 | |
218ca724 WD |
3219 | * The patch itself. If you are using git (which is *strongly* |
3220 | recommended) you can easily generate the patch using the | |
7ca9296e | 3221 | "git format-patch". If you then use "git send-email" to send it to |
218ca724 WD |
3222 | the U-Boot mailing list, you will avoid most of the common problems |
3223 | with some other mail clients. | |
3224 | ||
3225 | If you cannot use git, use "diff -purN OLD NEW". If your version of | |
3226 | diff does not support these options, then get the latest version of | |
3227 | GNU diff. | |
c609719b | 3228 | |
218ca724 WD |
3229 | The current directory when running this command shall be the parent |
3230 | directory of the U-Boot source tree (i. e. please make sure that | |
3231 | your patch includes sufficient directory information for the | |
3232 | affected files). | |
6dff5529 | 3233 | |
218ca724 WD |
3234 | We prefer patches as plain text. MIME attachments are discouraged, |
3235 | and compressed attachments must not be used. | |
c609719b | 3236 | |
2729af9d WD |
3237 | * If one logical set of modifications affects or creates several |
3238 | files, all these changes shall be submitted in a SINGLE patch file. | |
52f52c14 | 3239 | |
2729af9d WD |
3240 | * Changesets that contain different, unrelated modifications shall be |
3241 | submitted as SEPARATE patches, one patch per changeset. | |
8bde7f77 | 3242 | |
52f52c14 | 3243 | |
2729af9d | 3244 | Notes: |
c609719b | 3245 | |
6de80f21 | 3246 | * Before sending the patch, run the buildman script on your patched |
2729af9d WD |
3247 | source tree and make sure that no errors or warnings are reported |
3248 | for any of the boards. | |
c609719b | 3249 | |
2729af9d WD |
3250 | * Keep your modifications to the necessary minimum: A patch |
3251 | containing several unrelated changes or arbitrary reformats will be | |
3252 | returned with a request to re-formatting / split it. | |
c609719b | 3253 | |
2729af9d WD |
3254 | * If you modify existing code, make sure that your new code does not |
3255 | add to the memory footprint of the code ;-) Small is beautiful! | |
3256 | When adding new features, these should compile conditionally only | |
3257 | (using #ifdef), and the resulting code with the new feature | |
3258 | disabled must not need more memory than the old code without your | |
3259 | modification. | |
90dc6704 | 3260 | |
0668236b WD |
3261 | * Remember that there is a size limit of 100 kB per message on the |
3262 | u-boot mailing list. Bigger patches will be moderated. If they are | |
3263 | reasonable and not too big, they will be acknowledged. But patches | |
3264 | bigger than the size limit should be avoided. |