@ -34,12 +34,14 @@ In general, all boards for which a configuration option exists in the
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
@ -48,7 +50,7 @@ Where to get help:
==================
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
@ -58,7 +60,7 @@ http://dir.gmane.org/gmane.comp.boot-loaders.u-boot
Where to get source code:
=========================
The U-Boot source code is maintained in the g it repository at
The U-Boot source code is maintained in the G it 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
@ -133,79 +135,24 @@ Directory Hierarchy:
/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
@ -213,13 +160,12 @@ Directory Hierarchy:
/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:
@ -239,11 +185,11 @@ There are two classes of configuration variables:
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:
@ -257,10 +203,9 @@ Example: For a TQM823L module 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:
--------------------
@ -277,13 +222,25 @@ Board Initialisation Flow:
--------------------------
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 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
Execution starts with start.S with three functions called during init after
that. The purpose and limitations of each is described below.
and so on. From there, three functions are called; the purpose and
limitations of each of these funct ion s are described below.
lowlevel_init():
- purpose: essential init to permit execution to reach board_init_f()
@ -6630,7 +6587,8 @@ it:
* 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.
Robert P. J. Day
9 years ago
committed by
Tom Rini