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Commit | Line | Data |
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f1d2b313 HS |
1 | To make relocation on arm working, the following changes are done: |
2 | ||
3 | Add new compilerflag: | |
4 | ||
5 | -fPIC | |
6 | ||
7 | -> compiler generates position independent code | |
8 | ||
9 | changes in board code: | |
10 | ||
11 | - dram_init: | |
12 | - bd pointer is now at this point not accessible, so only | |
13 | detect the real dramsize, and store it in gd->ram_size. | |
14 | best detected with get_ram_size(); | |
15 | ToDo: move there also the dram initialization on boards where | |
16 | it is possible. | |
17 | - setup the bd_t dram bank info in the new function | |
18 | dram_init_banksize(). | |
19 | ||
20 | - board.c code is adapted from ppc code | |
21 | ||
22 | - undef CONFIG_RELOC_FIXUP_WORKS | |
23 | ||
24 | -> cmdtabl, and subcommand table must be handled from "hand" | |
25 | collected in section "__datarellocal_start". | |
26 | ||
27 | - How To fixup the sections: | |
28 | ||
29 | __datarel_start, __datarelrolocal_start, __datarellocal_start and | |
30 | __datarelro_start | |
31 | ||
32 | automatically? Then it should be possible to define again | |
33 | CONFIG_RELOC_FIXUP_WORKS | |
34 | ||
35 | - irq stack setup is now not longer on a fix position, instead it is | |
36 | calculated in board_init_f, and stored in gd->irq_sp | |
37 | ||
38 | ------------------------------------------------------------------------------------- | |
39 | ||
40 | To compile a board without relocation, define CONFIG_SYS_ARM_WITHOUT_RELOC | |
41 | This possibility will removed!! So please fix your board to compile without | |
42 | CONFIG_SYS_ARM_WITHOUT_RELOC defined!!! | |
43 | ||
44 | ------------------------------------------------------------------------------------- | |
45 | ||
ab86f72c HS |
46 | For boards which boot from nand_spl, it is possible to save a copy |
47 | if TEXT_BASE == relocation address! This prevents that uboot code | |
48 | is copied again in relocate_code(). | |
49 | ||
50 | example for the tx25 board: | |
51 | ||
52 | a) cpu starts | |
53 | b) it copies the first page in nand to internal ram | |
54 | (nand_spl_code) | |
55 | c) end executes this code | |
56 | d) this initialize CPU, RAM, ... and copy itself to RAM | |
57 | (this bin must fit in one page, so board_init_f() | |
58 | don;t fit in it ... ) | |
59 | e) there it copy u-boot to CONFIG_SYS_NAND_U_BOOT_DST and | |
60 | starts this image @ CONFIG_SYS_NAND_U_BOOT_START | |
61 | f) u-boot code steps through board_init_f() and calculates | |
62 | the relocation address and copy itself to it | |
63 | ||
64 | If TEXT_BASE == relocation address, the copying of u-boot | |
65 | in f) could be saved. | |
66 | ||
67 | ------------------------------------------------------------------------------------- | |
68 | ||
f1d2b313 HS |
69 | ToDo: |
70 | ||
71 | - fill in bd_t infos (check) | |
72 | - adapt all boards | |
73 | ||
74 | - maybe adapt TEXT_BASE (this must be checked from board maintainers) | |
75 | This *must* be done for boards, which boot from NOR flash | |
76 | ||
77 | on other boards if TEXT_BASE = relocation baseaddr, this saves | |
78 | one copying from u-boot code. | |
79 | ||
80 | - new function dram_init_banksize() is actual board specific. Maybe | |
81 | we make a weak default function in arch/arm/lib/board.c ? | |
82 | ||
83 | ------------------------------------------------------------------------------------- | |
84 | ||
85 | Relocation with NAND_SPL (example for the tx25): | |
86 | ||
87 | - cpu copies the first page from NAND to 0xbb000000 (IMX_NFC_BASE) | |
88 | and start with code execution on this address. | |
89 | ||
90 | - The First page contains u-boot code from u-boot:nand_spl/nand_boot_fsl_nfc.c | |
91 | which inits the dram, cpu registers, reloacte itself to TEXT_BASE and loads | |
92 | the "real" u-boot to CONFIG_SYS_NAND_U_BOOT_DST and starts execution | |
93 | @CONFIG_SYS_NAND_U_BOOT_START | |
94 | ||
95 | - This u-boot does no ram int, nor cpu register setup. Just looks | |
96 | where it have to relocate and relocate itself to this address. | |
97 | If relocate address = TEXT_BASE(not the same, as the TEXT_BASE | |
98 | from the nand_spl code), no need to copy, just go on with bss clear | |
99 | and jump to board_init_r. | |
100 | ||
101 | ------------------------------------------------------------------------------------- | |
102 | ||
103 | Relocation: | |
104 | How to translate flash addresses in GOT to ram addresses. | |
105 | This is automagically done from code, but this example | |
106 | shows, how this magic code works ;-) | |
107 | (example on the qong board) | |
108 | ||
109 | Find a variable: | |
110 | ||
111 | a) search it in System.map | |
112 | (for example flash_info) | |
113 | ||
114 | a005b4c0 B BootpID | |
115 | a005b4c4 B BootpTry | |
116 | a005b4c8 b slave | |
117 | a005b4cc B flash_info | |
118 | ^^^^^^^^ | |
119 | a005c908 b saved_sector.4002 | |
120 | a005c910 b cfi_mtd_info | |
121 | a005c9c0 b cfi_mtd_names | |
122 | a005c9d0 B mtd_table | |
123 | ||
124 | --------------------------------------- | |
125 | ||
126 | b) create hexdump from u-boot code: | |
127 | ||
128 | hexdump -C u-boot > gnlmpfhex | |
129 | ||
130 | --------------------------------------- | |
131 | ||
132 | c) search the variables address in the hexdump | |
133 | ||
134 | ||
135 | * | |
136 | 0005fc80 00 00 00 00 00 00 00 00 2c 06 01 a0 18 cd 05 a0 |........,.......| | |
137 | 0005fc90 9c d4 05 a0 bc b4 05 a0 1c 7f 05 a0 f0 05 01 a0 |................| | |
138 | 0005fca0 08 5a 04 a0 1c ab 05 a0 ec a4 05 a0 98 c3 01 a0 |.Z..............| | |
139 | 0005fcb0 a0 d6 05 a0 04 71 05 a0 c0 f9 00 a0 3c cd 05 a0 |.....q......<...| | |
140 | 0005fcc0 cc b4 05 a0 f0 fa 00 a0 f0 d6 05 a0 10 86 05 a0 |................| | |
141 | ^^^^^^^^^^^ | |
142 | 0005fcd0 a4 16 06 a0 dc 64 05 a0 18 86 05 a0 52 48 05 a0 |.....d......RH..| | |
143 | 0005fce0 c0 86 05 a0 24 6e 02 a0 b4 6c 05 a0 b0 94 01 a0 |....$n...l......| | |
144 | 0005fcf0 1c 86 05 a0 50 85 05 a0 d4 0c 06 a0 bc 0b 06 a0 |....P...........| | |
145 | ||
146 | ||
147 | -> 0005fcc0 | |
148 | ||
149 | ---------------------------------------- | |
150 | ||
151 | d) know we calculate this address in RAM | |
152 | ||
153 | ||
154 | 8ff08000 (new address of code in RAM *1) | |
155 | ||
156 | + 0005fcc0 | |
157 | ||
158 | - 00008000 (offset of text *2) | |
159 | ||
160 | ---------- | |
161 | ||
162 | 8ff5fcc0 -> Addr GOT in RAM | |
163 | ||
164 | *1: | |
165 | activate debug and look for the line: | |
166 | Now running in RAM - U-Boot at: 8ff08000 | |
167 | ^^^^^^^^ | |
168 | new address of u-boot code in RAM | |
169 | ||
170 | *2: | |
171 | Section Headers: | |
172 | [Nr] Name Type Addr Off Size ES Flg Lk Inf Al | |
173 | [ 0] NULL 00000000 000000 000000 00 0 0 0 | |
174 | [ 1] .text PROGBITS a0000000 008000 04599c 00 AX 0 0 32 | |
175 | ^^^^^^ | |
176 | Offset of text | |
177 | ||
178 | ---------------------------------------- | |
179 | ||
180 | e) now we look in 8ff5fcc0 (RAM) | |
181 | ||
182 | ||
183 | QongEVB>md 0x8ff5fcc0 | |
184 | 8ff5fcc0 : a005b4cc a000faf0 a005d6f0 a0058610 ................ | |
185 | ^^^^^^^^ | |
186 | Bingo, here we have the old flash address (when relocation | |
187 | is working, here is the fixed ram address. see @ f, how | |
188 | it gets calculated) | |
189 | ||
190 | ||
191 | ---------------------------------------- | |
192 | ||
193 | f) now translate it in the new RAM address | |
194 | ||
195 | a005b4cc | |
196 | ||
197 | - a0000000 TextBase | |
198 | ||
199 | + 8ff08000 new address of u-boot in ram | |
200 | ---------- | |
201 | 8ff634cc | |
202 | ||
203 | QongEVB>mm 0x8ff5fcc0 0x8ff634cc 1 | |
204 | QongEVB>md 0x8ff5fcc0 | |
205 | 8ff5fcc0 : 8ff634cc a000faf0 a005d6f0 a0058610 .4.............. | |
206 | 8ff5fcd0 : a00616a4 a00564dc a0058618 a0054852 .....d......RH.. | |
207 | ||
208 | As this must be done for all address in the GOT, the u-boot | |
209 | code did this automagically ... :-) | |
210 | ||
211 | ---------------------------------------------- | |
212 | ||
213 | g) check if the new address is really in the bss section: | |
214 | ||
215 | bss start: | |
216 | 8ff6054c (8ff08000 + 0005854C monitorlen) | |
217 | ||
218 | bss end: | |
219 | 8ff698ac (8ff08000 + 618AC) | |
220 | ||
221 | 8ff634cc is in bss :-) | |
222 | ||
223 | ---------------------------------------------- | |
224 | ||
225 | h) u-boot prints: | |
226 | ||
227 | important addresses: | |
228 | ||
229 | U-Boot code: A0000000 -> A005854C BSS: -> A00618AC TextBase 0xa0000000 | |
230 | Now running in RAM - U-Boot at: 8ff08000 relocBase 0x8ff08000 | |
231 | ||
232 | ||
233 | --------- | |
234 | ||
235 | U-Boot 2010.06-rc2-00002-gf8fbb25-dirty (Jun 18 2010 - 17:07:19) | |
236 | ||
237 | U-Boot code: A0000000 -> A005854C BSS: -> A00618AC | |
238 | CPU: Freescale i.MX31 at 398 MHz | |
239 | Board: DAVE/DENX Qong | |
240 | mon: FFFFFFFF gd->monLen: 000618AC | |
241 | Top of RAM usable for U-Boot at: 90000000 | |
242 | LCD panel info: 640 x 480, 16 bit/pix | |
243 | Reserving 600k for LCD Framebuffer at: 8ff6a000 | |
244 | Reserving 390k for U-Boot at: 8ff08000 | |
245 | Reserving 1280k for malloc() at: 8fdc8000 | |
246 | Reserving 28 Bytes for Board Info at: 8fdc7fe4 | |
247 | Reserving 48 Bytes for Global Data at: 8fdc7fb4 | |
248 | New Stack Pointer is: 8fdc7fb0 | |
249 | RAM Configuration: | |
250 | Bank #0: 80000000 256 MiB | |
251 | mon: 0005854C gd->monLen: 000618AC | |
252 | Now running in RAM - U-Boot at: 8ff08000 | |
253 | ||
254 | ------------------------------------------------------------------------------------- | |
255 | ||
256 | Debugging u-boot in RAM: | |
257 | (example on the qong board) | |
258 | ||
259 | a) add in config.mk: | |
260 | ||
261 | PLATFORM_CPPFLAGS += -DDEBUG | |
262 | ||
263 | ----------------- | |
264 | ||
265 | b) start debugger | |
266 | ||
267 | arm-linux-gdb u-boot | |
268 | ||
269 | [hs@pollux u-boot]$ arm-linux-gdb u-boot | |
270 | GNU gdb Red Hat Linux (6.7-2rh) | |
271 | Copyright (C) 2007 Free Software Foundation, Inc. | |
272 | License GPLv3+: GNU GPL version 3 or later <http://gnu.org/licenses/gpl.html> | |
273 | This is free software: you are free to change and redistribute it. | |
274 | There is NO WARRANTY, to the extent permitted by law. Type "show copying" | |
275 | and "show warranty" for details. | |
276 | This GDB was configured as "--host=i686-pc-linux-gnu --target=arm-linux". | |
277 | The target architecture is set automatically (currently arm) | |
278 | .. | |
279 | (gdb) | |
280 | ||
281 | ----------------- | |
282 | ||
283 | c) connect to target | |
284 | ||
285 | target remote bdi10:2001 | |
286 | ||
287 | (gdb) target remote bdi10:2001 | |
288 | Remote debugging using bdi10:2001 | |
289 | 0x8ff17f10 in ?? () | |
290 | (gdb) | |
291 | ||
292 | ----------------- | |
293 | ||
294 | d) discard symbol-file | |
295 | ||
296 | (gdb) symbol-file | |
297 | Discard symbol table from `/home/hs/celf/u-boot/u-boot'? (y or n) y | |
298 | No symbol file now. | |
299 | (gdb) | |
300 | ||
301 | ----------------- | |
302 | ||
303 | e) load new symbol table: | |
304 | ||
305 | (gdb) add-symbol-file u-boot 0x8ff08000 | |
306 | add symbol table from file "u-boot" at | |
307 | .text_addr = 0x8ff08000 | |
308 | (y or n) y | |
309 | Reading symbols from /home/hs/celf/u-boot/u-boot...done. | |
310 | (gdb) c | |
311 | Continuing. | |
312 | ^C | |
313 | Program received signal SIGSTOP, Stopped (signal). | |
314 | 0x8ff17f18 in serial_getc () at serial_mxc.c:192 | |
315 | 192 while (__REG(UART_PHYS + UTS) & UTS_RXEMPTY); | |
316 | (gdb) | |
317 | ||
318 | add-symbol-file u-boot 0x8ff08000 | |
319 | ^^^^^^^^^^ | |
320 | get this address from u-boot debug printfs | |
321 | ||
322 | U-Boot 2010.06-rc2-00009-gf77b8b8-dirty (Jun 22 2010 - 09:43:46) | |
323 | ||
324 | U-Boot code: A0000000 -> A0058BAC BSS: -> A0061F10 | |
325 | CPU: Freescale i.MX31 at 398 MHz | |
326 | Board: DAVE/DENX Qong | |
327 | mon: FFFFFFFF gd->monLen: 00061F10 | |
328 | Top of RAM usable for U-Boot at: 90000000 | |
329 | LCD panel info: 640 x 480, 16 bit/pix | |
330 | Reserving 600k for LCD Framebuffer at: 8ff6a000 | |
331 | Reserving 391k for U-Boot at: 8ff08000 | |
332 | ^^^^^^^^ | |
333 | Reserving 1280k for malloc() at: 8fdc8000 | |
334 | Reserving 24 Bytes for Board Info at: 8fdc7fe8 | |
335 | Reserving 52 Bytes for Global Data at: 8fdc7fb4 | |
336 | New Stack Pointer is: 8fdc7fb0 | |
337 | RAM Configuration: | |
338 | Bank #0: 80000000 256 MiB | |
339 | relocation Offset is: eff08000 | |
340 | mon: 00058BAC gd->monLen: 00061F10 | |
341 | Now running in RAM - U-Boot at: 8ff08000 | |
342 | ^^^^^^^^ | |
343 | ||
344 | Now you can use gdb as usual :-) |