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Ronald G. Minnich d6b16f54b9 Set armv7 up for cpu_info to work as on x86 (so threads can work)
On x86, cpu_info lives at the top of stack. Make the arm do that as
well, as the threading model needs that and so will multicore support.

As part of this change, make the stack size a power of 2.
Also make it much smaller -- 2048 bytes is PLENTY for ram stage.

Note that the small stack size is counterintuitive for rom stage.  How
can this work in rom stage, which needs a HUGE stack for lzma? The
main use of STACK_SIZE has always been in ram stage; since 2002 or so
it was to size per-core stacks (see, e.g.,

src/arch/x86/lib/c_start.S:.space CONFIG_MAX_CPUS*CONFIG_STACK_SIZE

and, more recently, thread stacks. So, we define the STACK_TOP for rom
and ram stage, but the STACK_SIZE has no real effect on the ROM stage
(no hardware red zones on the stack) and hence we're ok with actually
defining the "wrong" stack size. In fact, the coreboot_ram ldscript
for armv7 sizes the stack by subtracting CONFIG_STACK_BOTTOM from
CONFIG_STACK_TOP, so we replicate that arithmetic in bootblock.inc

Observed stack usage in ramstage:
BS: BS_PAYLOAD_LOAD times (us): entry 1 run 153887 exit 1
Jumping to boot code at 23104044
CPU0: stack: 02072800 - 02073000, lowest used address 020728d4, stack used: 1836 bytes
entry    = 23104044

Which means we do need 2K, not 1K.

Change-Id: I1a21db87081597efe463095bfd33c89eba1d569f
Signed-off-by: Ronald G. Minnich <rminnich@gmail.com>
Reviewed-on: https://gerrit.chromium.org/gerrit/66135
Reviewed-by: Ronald G. Minnich <rminnich@chromium.org>
Tested-by: Ronald G. Minnich <rminnich@chromium.org>
Commit-Queue: Ronald G. Minnich <rminnich@chromium.org>
(cherry picked from commit f011097e9f2bfb2f4c1109d465be89a79a65ba3e)
Signed-off-by: Isaac Christensen <isaac.christensen@se-eng.com>
Reviewed-on: http://review.coreboot.org/6501
Tested-by: build bot (Jenkins)
Reviewed-by: David Hendricks <dhendrix@chromium.org>
Reviewed-by: Edward O'Callaghan <eocallaghan@alterapraxis.com>
Reviewed-by: Paul Menzel <paulepanter@users.sourceforge.net>
2014-08-06 22:07:06 +02:00
3rdparty@45f0c04fd7 acpigen: Add acpigen_emit_eisaid. 2014-06-01 01:24:53 +02:00
documentation Documentation: Use correct file name for the build guide in the Makefile 2014-07-04 19:03:10 +02:00
payloads libpayload: Change CONFIG_* to CONFIG_LP_* in the kconfig. 2014-08-05 18:44:08 +02:00
src Set armv7 up for cpu_info to work as on x86 (so threads can work) 2014-08-06 22:07:06 +02:00
util sconfig: improve argument parsing 2014-08-04 20:57:12 +02:00
.gitignore git-ignore site-local 2014-04-01 08:55:02 +02:00
.gitmodules gitmodules: Fix 3rdparty updates 2013-06-28 00:56:43 +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 build system: avoid warning about missing .xcompile 2014-07-20 19:51:10 +02:00
Makefile.inc build system: avoid more race conditions 2014-07-10 20:56:35 +02:00
README Update README with newer version of the text from the web page 2011-06-15 10:16:33 +02:00
toolchain.inc build system: remove duplicate architecture list 2014-07-30 21:06:43 +02:00

-------------------------------------------------------------------------------
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.