Makefile have been tested to some extent and can be considered
"working". In fact, many of them are used in production systems.
-In case of problems see the CHANGELOG and CREDITS files to find out
-who contributed the specific port. The boards.cfg file lists board
-maintainers.
+In case of problems see the CHANGELOG file to find out who contributed
+the specific port. In addition, there are various MAINTAINERS files
+scattered throughout the U-Boot source identifying the people or
+companies responsible for various boards and subsystems.
-Note: There is no CHANGELOG file in the actual U-Boot source tree;
-it can be created dynamically from the Git log using:
+Note: As of August, 2010, there is no longer a CHANGELOG file in the
+actual U-Boot source tree; however, it can be created dynamically
+from the Git log using:
make CHANGELOG
==================
In case you have questions about, problems with or contributions for
-U-Boot you should send a message to the U-Boot mailing list at
+U-Boot, you should send a message to the U-Boot mailing list at
<u-boot@lists.denx.de>. There is also an archive of previous traffic
on the mailing list - please search the archive before asking FAQ's.
Please see http://lists.denx.de/pipermail/u-boot and
Where to get source code:
=========================
-The U-Boot source code is maintained in the git repository at
+The U-Boot source code is maintained in the Git repository at
git://www.denx.de/git/u-boot.git ; you can browse it online at
http://www.denx.de/cgi-bin/gitweb.cgi?p=u-boot.git;a=summary
/arch Architecture specific files
/arc Files generic to ARC architecture
- /cpu CPU specific files
- /arc700 Files specific to ARC 700 CPUs
- /lib Architecture specific library files
/arm Files generic to ARM architecture
- /cpu CPU specific files
- /arm720t Files specific to ARM 720 CPUs
- /arm920t Files specific to ARM 920 CPUs
- /at91 Files specific to Atmel AT91RM9200 CPU
- /imx Files specific to Freescale MC9328 i.MX CPUs
- /s3c24x0 Files specific to Samsung S3C24X0 CPUs
- /arm926ejs Files specific to ARM 926 CPUs
- /arm1136 Files specific to ARM 1136 CPUs
- /pxa Files specific to Intel XScale PXA CPUs
- /sa1100 Files specific to Intel StrongARM SA1100 CPUs
- /lib Architecture specific library files
/avr32 Files generic to AVR32 architecture
- /cpu CPU specific files
- /lib Architecture specific library files
/blackfin Files generic to Analog Devices Blackfin architecture
- /cpu CPU specific files
- /lib Architecture specific library files
/m68k Files generic to m68k architecture
- /cpu CPU specific files
- /mcf52x2 Files specific to Freescale ColdFire MCF52x2 CPUs
- /mcf5227x Files specific to Freescale ColdFire MCF5227x CPUs
- /mcf532x Files specific to Freescale ColdFire MCF5329 CPUs
- /mcf5445x Files specific to Freescale ColdFire MCF5445x CPUs
- /mcf547x_8x Files specific to Freescale ColdFire MCF547x_8x CPUs
- /lib Architecture specific library files
/microblaze Files generic to microblaze architecture
- /cpu CPU specific files
- /lib Architecture specific library files
/mips Files generic to MIPS architecture
- /cpu CPU specific files
- /mips32 Files specific to MIPS32 CPUs
- /mips64 Files specific to MIPS64 CPUs
- /lib Architecture specific library files
/nds32 Files generic to NDS32 architecture
- /cpu CPU specific files
- /n1213 Files specific to Andes Technology N1213 CPUs
- /lib Architecture specific library files
/nios2 Files generic to Altera NIOS2 architecture
- /cpu CPU specific files
- /lib Architecture specific library files
/openrisc Files generic to OpenRISC architecture
- /cpu CPU specific files
- /lib Architecture specific library files
/powerpc Files generic to PowerPC architecture
- /cpu CPU specific files
- /mpc5xx Files specific to Freescale MPC5xx CPUs
- /mpc5xxx Files specific to Freescale MPC5xxx CPUs
- /mpc8xx Files specific to Freescale MPC8xx CPUs
- /mpc8260 Files specific to Freescale MPC8260 CPUs
- /mpc85xx Files specific to Freescale MPC85xx CPUs
- /ppc4xx Files specific to AMCC PowerPC 4xx CPUs
- /lib Architecture specific library files
+ /sandbox Files generic to HW-independent "sandbox"
/sh Files generic to SH architecture
- /cpu CPU specific files
- /sh2 Files specific to sh2 CPUs
- /sh3 Files specific to sh3 CPUs
- /sh4 Files specific to sh4 CPUs
- /lib Architecture specific library files
/sparc Files generic to SPARC architecture
- /cpu CPU specific files
- /leon2 Files specific to Gaisler LEON2 SPARC CPU
- /leon3 Files specific to Gaisler LEON3 SPARC CPU
- /lib Architecture specific library files
/x86 Files generic to x86 architecture
- /cpu CPU specific files
- /lib Architecture specific library files
/api Machine/arch independent API for external apps
/board Board dependent files
/common Misc architecture independent functions
+/configs Board default configuration files
/disk Code for disk drive partition handling
/doc Documentation (don't expect too much)
/drivers Commonly used device drivers
/examples Example code for standalone applications, etc.
/fs Filesystem code (cramfs, ext2, jffs2, etc.)
/include Header Files
-/lib Files generic to all architectures
- /libfdt Library files to support flattened device trees
- /lzma Library files to support LZMA decompression
- /lzo Library files to support LZO decompression
+/lib Library routines generic to all architectures
+/Licenses Various license files
/net Networking code
/post Power On Self Test
-/spl Secondary Program Loader framework
+/scripts Various build scripts and Makefiles
+/test Various unit test files
/tools Tools to build S-Record or U-Boot images, etc.
Software Configuration:
you don't know what you're doing; they have names beginning with
"CONFIG_SYS_".
-Later we will add a configuration tool - probably similar to or even
-identical to what's used for the Linux kernel. Right now, we have to
-do the configuration by hand, which means creating some symbolic
-links and editing some configuration files. We use the TQM8xxL boards
-as an example here.
+Previously, all configuration was done by hand, which involved creating
+symbolic links and editing configuration files manually. More recently,
+U-Boot has added the Kbuild infrastructure used by the Linux kernel,
+allowing you to use the "make menuconfig" command to configure your
+build.
Selection of Processor Architecture and Board Type:
cd u-boot
make TQM823L_defconfig
-For the Cogent platform, you need to specify the CPU type as well;
-e.g. "make cogent_mpc8xx_defconfig". And also configure the cogent
-directory according to the instructions in cogent/README.
-
+Note: If you're looking for the default configuration file for a board
+you're sure used to be there but is now missing, check the file
+doc/README.scrapyard for a list of no longer supported boards.
Sandbox Environment:
--------------------
--------------------------
This is the intended start-up flow for boards. This should apply for both
-SPL and U-Boot proper (i.e. they both follow the same rules). At present SPL
-mostly uses a separate code path, but the funtion names and roles of each
-function are the same. Some boards or architectures may not conform to this.
-At least most ARM boards which use CONFIG_SPL_FRAMEWORK conform to this.
+SPL and U-Boot proper (i.e. they both follow the same rules).
+
+Note: "SPL" stands for "Secondary Program Loader," which is explained in
+more detail later in this file.
+
+At present, SPL mostly uses a separate code path, but the function names
+and roles of each function are the same. Some boards or architectures
+may not conform to this. At least most ARM boards which use
+CONFIG_SPL_FRAMEWORK conform to this.
-Execution starts with start.S with three functions called during init after
-that. The purpose and limitations of each is described below.
+Execution typically starts with an architecture-specific (and possibly
+CPU-specific) start.S file, such as:
+
+ - arch/arm/cpu/armv7/start.S
+ - arch/powerpc/cpu/mpc83xx/start.S
+ - arch/mips/cpu/start.S
+
+and so on. From there, three functions are called; the purpose and
+limitations of each of these functions are described below.
lowlevel_init():
- purpose: essential init to permit execution to reach board_init_f()
'Sane' compilers will generate smaller code if
CONFIG_PRE_CON_BUF_SZ is a power of 2
-- Safe printf() functions
- Define CONFIG_SYS_VSNPRINTF to compile in safe versions of
- the printf() functions. These are defined in
- include/vsprintf.h and include snprintf(), vsnprintf() and
- so on. Code size increase is approximately 300-500 bytes.
- If this option is not given then these functions will
- silently discard their buffer size argument - this means
- you are not getting any overflow checking in this case.
-
- Boot Delay: CONFIG_BOOTDELAY - in seconds
Delay before automatically booting the default image;
set to -1 to disable autoboot.
CONFIG_TPM_TIS_I2C_BURST_LIMITATION
Define the burst count bytes upper limit
+ CONFIG_TPM_ST33ZP24
+ Support for STMicroelectronics TPM devices. Requires DM_TPM support.
+
+ CONFIG_TPM_ST33ZP24_I2C
+ Support for STMicroelectronics ST33ZP24 I2C devices.
+ Requires TPM_ST33ZP24 and I2C.
+
+ CONFIG_TPM_ST33ZP24_SPI
+ Support for STMicroelectronics ST33ZP24 SPI devices.
+ Requires TPM_ST33ZP24 and SPI.
+
CONFIG_TPM_ATMEL_TWI
Support for Atmel TWI TPM device. Requires I2C support.
- RTS/CTS Flow control enable:
CONFIG_HWFLOW
-- Modem debug support:
- CONFIG_MODEM_SUPPORT_DEBUG
-
- Enables debugging stuff (char screen[1024], dbg())
- for modem support. Useful only with BDI2000.
-
- Interrupt support (PPC):
There are common interrupt_init() and timer_interrupt()
Scratch address used by the alternate memory test
You only need to set this if address zero isn't writeable
-- CONFIG_SYS_MEM_TOP_HIDE (PPC only):
+- CONFIG_SYS_MEM_RESERVE_SECURE
+ If defined, the size of CONFIG_SYS_MEM_RESERVE_SECURE memory
+ is substracted from total RAM and won't be reported to OS.
+ This memory can be used as secure memory. A variable
+ gd->secure_ram is used to track the location. In systems
+ the RAM base is not zero, or RAM is divided into banks,
+ this variable needs to be recalcuated to get the address.
+
+- CONFIG_SYS_MEM_TOP_HIDE:
If CONFIG_SYS_MEM_TOP_HIDE is defined in the board config header,
this specified memory area will get subtracted from the top
(end) of RAM and won't get "touched" at all by U-Boot. By
- CONFIG_SYS_DEBUG_SERVER_DRAM_BLOCK_MIN_SIZE
Define minimum DDR size required for debug server image
-- CONFIG_SYS_MEM_TOP_HIDE_MIN
- Define minimum DDR size to be hided from top of the DDR memory
+- CONFIG_SYS_MC_RSV_MEM_ALIGN
+ Define alignment of reserved memory MC requires
Reproducible builds
-------------------
to port U-Boot to your hardware platform. To do this, follow these
steps:
-1. Add a new configuration option for your board to the toplevel
- "boards.cfg" file, using the existing entries as examples.
- Follow the instructions there to keep the boards in order.
-2. Create a new directory to hold your board specific code. Add any
+1. Create a new directory to hold your board specific code. Add any
files you need. In your board directory, you will need at least
- the "Makefile", a "<board>.c", "flash.c" and "u-boot.lds".
-3. Create a new configuration file "include/configs/<board>.h" for
- your board
+ the "Makefile" and a "<board>.c".
+2. Create a new configuration file "include/configs/<board>.h" for
+ your board.
3. If you're porting U-Boot to a new CPU, then also create a new
directory to hold your CPU specific code. Add any files you need.
4. Run "make <board>_defconfig" with your new name.
* A CHANGELOG entry as plaintext (separate from the patch)
-* For major contributions, your entry to the CREDITS file
+* For major contributions, add a MAINTAINERS file with your
+ information and associated file and directory references.
* When you add support for a new board, don't forget to add a
maintainer e-mail address to the boards.cfg file, too.