summaryrefslogtreecommitdiffstats
path: root/README
diff options
context:
space:
mode:
authorRobert P. J. Day <rpjday@crashcourse.ca>2015-12-19 07:16:10 -0500
committerTom Rini <trini@konsulko.com>2016-01-08 10:15:43 -0500
commit7207b366d580b256dc0951bdb0c5eb453929e5d2 (patch)
treea4d87e16ba2152f56d0f3de83c04d2729378fcf2 /README
parentd7b4ca2b6f551c9de89292862216e365f7156ee0 (diff)
downloadtalos-obmc-uboot-7207b366d580b256dc0951bdb0c5eb453929e5d2.zip
talos-obmc-uboot-7207b366d580b256dc0951bdb0c5eb453929e5d2.tar.gz
doc: Tidy up first part of top-level README file
First (small) pass at tidying up the README file, including: * remove references to obsolete CREDITS file * remove (some) references to obsolete boards.cfg file * remove at least one reference to a "scrapped" board * cut down unnecessarily detailed directory hierarchy * bunch of grammar and spelling tweaks Signed-off-by: Robert P. J. Day <rpjday@crashcourse.ca>
Diffstat (limited to 'README')
-rw-r--r--README128
1 files changed, 43 insertions, 85 deletions
diff --git a/README b/README
index 43f307f..5ac2d44 100644
--- a/README
+++ b/README
@@ -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 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
@@ -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 functions 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.
OpenPOWER on IntegriCloud