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Konstantin Aladyshev 7fcbbb09fd AGESA: Fix bug in AMD_DISABLE_STACK_FAMILY_HOOK_F15
_RDMSR instruction loads the contents of a 64-bit model specific register (MSR)
specified in the ECX register into registers EDX:EAX.
The EDX register is loaded with the high-order 32 bits of the MSR
and the EAX register is loaded with the low-order 32 bits.

EDX:EAX = MSR[ECX]

So bit 49 will be contained in EDX register.

Buggy code instead of bit 49 (CombineCr0Cd) sets bit [49-32=17] (PfcStrideDis).
PfcStrideDis bit disables stride prefetch generation. This leads to memory
bandwidth loss.

_________

Supermicro H8QGI board

After applying this change i observed huge memory bandwidth increase in tests
that runs on small amount of cores. But unfortunately it doesn't affect
overall bandwidth results on 4P system with 48 cores.
So i think that in this system leading limiting factor is
AMD HT-ASSIST feature (Probe filter).

But right now it is not working. System stucks in Linux boot. I have done
some experiments and figured out that stuck happens when system have cores in
compute unit (CU) other than CU with BSC (boot strap core).
CU is two cores (primary and seconary) that shares some things (L2 cache, FPU ...)
So with probe filter i can boot Linux with one (BSC)
or two (BSC + secondary core in its CU) cores.
And with this configuration i can see memory bandwidth on 1 core (or two cores)
close to original bios.

Change-Id: I5a95f5b753d600c70d3c93d36fecc687610c61cd
Signed-off-by: Konstantin Aladyshev <aladyshev@nicevt.ru>
Reviewed-on: http://review.coreboot.org/2588
Tested-by: build bot (Jenkins)
Reviewed-by: Marc Jones <marc.jones@se-eng.com>
2013-03-08 07:25:15 +01:00
3rdparty@dac1a18d18 Update 3rdparty mark to latest repository 2013-02-22 09:22:41 +01:00
documentation sconfig: rename lapic_cluster -> cpu_cluster 2013-02-14 07:07:20 +01:00
payloads libpayload: Turn on thumb interworking in libpayload. 2013-03-04 22:47:49 +01:00
src AGESA: Fix bug in AMD_DISABLE_STACK_FAMILY_HOOK_F15 2013-03-08 07:25:15 +01:00
util GPLv2 notice: Unify all files to just use one space in »MA 02110-1301« 2013-03-01 10:16:08 +01:00
.gitignore add a few entries to .gitignore 2013-01-10 22:51:20 +01:00
.gitmodules Add 3rdparty as submodule 2012-05-01 00:08:37 +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: Retire REQUIRES_BLOB 2013-02-19 11:00:41 +01:00
Makefile.inc build system: Retire REQUIRES_BLOB 2013-02-19 11:00:41 +01:00
README Update README with newer version of the text from the web page 2011-06-15 10:16:33 +02:00

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.