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Gabe Black 169c0df6b8 ARM: Use local versions of libgcc functions instead of linking against libgcc.
The flags used to compile libgcc may make it incompatible with the code it's
linked against, and/or the hardware it's going to run on. Rather than try to
tease the right libgcc from the compiler, lets just leave it out and use our
own implementations of the necessary functions.

Most of these implementations were taken from the Linux kernel, except for
uldivmod.S which was taken from a CL originally written for U-Boot by
Che-Liang Chiou in December of 2010. It was modified to not use the CLZ
instruction on machines that don't have it, anything earlier than ARMv5. The
top block was taken from an earlier version of the same CL which didn't use
CLZ in that spot. The later block was written from scratch.

BUG=None
TEST=Built and booted into the bootblock on nyan. Ran a series of tests which
divided and modded a 64 bit value by various 32 bit values which were powers
of 2. Confirmed that this function was used and that the returned value was
correct. Printed decimal and hex versions of some values and verified that
they equaled each other. Built and booted on pit with serial enabled.
BRANCH=None

Original-Change-Id: I7527e28af411b7aa7f94579be95a6b352a91a224
Original-Signed-off-by: Gabe Black <gabeblack@google.com>
Original-Reviewed-on: https://chromium-review.googlesource.com/172401
Original-Reviewed-by: David Hendricks <dhendrix@chromium.org>
Original-Commit-Queue: Gabe Black <gabeblack@chromium.org>
Original-Tested-by: Gabe Black <gabeblack@chromium.org>
(cherry picked from commit be8c7a8f3292a7d7651b7c6dafc9a2c53afbd402)

*** This second patch is cherry-picked and squashed again to
*** pick up the libgcc changes that were skipped previously.

arm: Move libgcc assembly macros to arch/asm.h

libgcc/macros.h contains some useful assembly macros that are common in
Linux kernel code and facilitate things such as unified ARM/THUMB
assembly. This patch moves it to a more general place where it can be
used by other code as well.

BUG=None
TEST=Snow still boots.

Original-Change-Id: If68e8930aaafa706c54cf9a156fac826b31bb193
Original-Signed-off-by: Julius Werner <jwerner@chromium.org>
Original-Reviewed-on: https://chromium-review.googlesource.com/182178
Original-Reviewed-by: Vincent Palatin <vpalatin@chromium.org>
(cherry picked from commit a780670def94a969829811fa8cf257f12b88f085)

*** Additional changes for stage specific builds

Signed-off-by: Marc Jones <marc.jones@se-eng.com>
Change-Id: Ie3e48f34ebf6fbe20c3dd76ecbcbea7844e9466e
Reviewed-on: http://review.coreboot.org/7322
Tested-by: build bot (Jenkins)
Reviewed-by: Stefan Reinauer <stefan.reinauer@coreboot.org>
2014-11-05 01:49:06 +01:00
3rdparty@f37e0e64ac AMD Steppe Eagle: Update reference to BLOBs repo (3rdparty) 2014-09-01 00:37:16 +02:00
documentation mkelfimage: remove 2014-10-08 14:27:24 +02:00
payloads SeaBIOS Makefile.inc: Remove build dir for uppermem option 2014-11-02 08:15:35 +01:00
src ARM: Use local versions of libgcc functions instead of linking against libgcc. 2014-11-05 01:49:06 +01:00
util inteltool: Show more info on sandy/ivy. 2014-11-05 00:02:25 +01:00
.gitignore .gitignore: add 3 executables that can be built in util/ 2014-08-11 06:26:01 +02:00
.gitmodules nvidia/cbootimage: avoid upstream's build system 2014-10-02 10:26:58 +02:00
.gitreview add .gitreview 2012-11-01 23:13:39 +01:00
COPYING update license template. 2006-08-12 22:03:36 +00:00
Makefile Makefile: Fix HOSTCC for clang 2014-10-30 07:46:05 +01:00
Makefile.inc build: fetch submodules as required 2014-11-04 08:59:04 +01:00
README Update README with newer version of the text from the web page 2011-06-15 10:16:33 +02:00
toolchain.inc Pipe stderr to /dev/null when getting LIBCLANG_RT_FILE_NAME 2014-10-29 16:19:12 +01:00

README

-------------------------------------------------------------------------------
coreboot README
-------------------------------------------------------------------------------

coreboot is a Free Software project aimed at replacing the proprietary BIOS
(firmware) found in most computers.  coreboot performs a little bit of
hardware initialization and then executes additional boot logic, called a
payload.

With the separation of hardware initialization and later boot logic,
coreboot can scale from specialized applications that run directly
firmware, run operating systems in flash, load custom
bootloaders, or implement firmware standards, like PC BIOS services or
UEFI. This allows for systems to only include the features necessary
in the target application, reducing the amount of code and flash space
required.

coreboot was formerly known as LinuxBIOS.


Payloads
--------

After the basic initialization of the hardware has been performed, any
desired "payload" can be started by coreboot.

See http://www.coreboot.org/Payloads for a list of supported payloads.


Supported Hardware
------------------

coreboot supports a wide range of chipsets, devices, and mainboards.

For details please consult:

 * http://www.coreboot.org/Supported_Motherboards
 * http://www.coreboot.org/Supported_Chipsets_and_Devices


Build Requirements
------------------

 * gcc / g++
 * make

Optional:

 * doxygen (for generating/viewing documentation)
 * iasl (for targets with ACPI support)
 * gdb (for better debugging facilities on some targets)
 * ncurses (for 'make menuconfig')
 * flex and bison (for regenerating parsers)


Building coreboot
-----------------

Please consult http://www.coreboot.org/Build_HOWTO for details.


Testing coreboot Without Modifying Your Hardware
------------------------------------------------

If you want to test coreboot without any risks before you really decide
to use it on your hardware, you can use the QEMU system emulator to run
coreboot virtually in QEMU.

Please see http://www.coreboot.org/QEMU for details.


Website and Mailing List
------------------------

Further details on the project, a FAQ, many HOWTOs, news, development
guidelines and more can be found on the coreboot website:

  http://www.coreboot.org

You can contact us directly on the coreboot mailing list:

  http://www.coreboot.org/Mailinglist


Copyright and License
---------------------

The copyright on coreboot is owned by quite a large number of individual
developers and companies. Please check the individual source files for details.

coreboot is licensed under the terms of the GNU General Public License (GPL).
Some files are licensed under the "GPL (version 2, or any later version)",
and some files are licensed under the "GPL, version 2". For some parts, which
were derived from other projects, other (GPL-compatible) licenses may apply.
Please check the individual source files for details.

This makes the resulting coreboot images licensed under the GPL, version 2.