coreboot-kgpe-d16

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Peter Stuge 751508ab01 northbridge/intel/i945: CHECK_SLFRCS_ON_RESUME Kconfig option Originally brought up by Sven Schnelle in March 2011 http://patchwork.coreboot.org/patch/2801/ http://www.coreboot.org/pipermail/coreboot/2011-March/064277.html On some mainboards it may be neccessary to reset early during resume from S3 if the SLFRCS register indicates that a memory channel is not guaranteed to be in self-refresh. On other mainboards, such as Lenovo X60 and T60, the check always creates false positives, effectively making it impossible to resume. The SLFRCS register is documented on page 197 of Mobile Intel® 945 Express Chipset Family Datasheet Document Number: 309219-006 which is publically available, and the register indicates if a memory channel is guaranteed to be in self-refresh mode (if bit = 1), or that a memory channel may or may not be in self-refresh mode (if bit = 0). The register can thus only be used to positively learn that memory is in self-refresh. It is not known for sure that memory is not in self-refresh. The register is reset by the PWROK signal, which should go low during S3, and go high again when resuming, so it is unsurprising that SLFRCS has already been cleared when we read the register. Sven's measurements of the CKE signal on a ThinkPad shows that memory remains in self-refresh indefinitely, until coreboot re-initializes the memory controller, even when SLFRCS bits were = 0. Boards which require a warm reset when SLFRCS bits are cleared must now explicitly enable the check in the mainboard Kconfig file. This commit selects the new option in all existing i945 mainboards. A follow-up commit will remove the option for ThinkPads. Change-Id: I02320675efb8fde05c371ef243ba5093a4da6d11 Signed-off-by: Peter Stuge <peter@stuge.se> Reviewed-on: http://review.coreboot.org/590 Tested-by: build bot (Jenkins) Reviewed-by: Sven Schnelle <svens@stackframe.org>		2012-01-31 14:52:22 +01:00
documentation	Whitespace/typo/cosmetic fixes (trivial).	2010-09-23 18:48:27 +00:00
payloads	libpayload: Allow using CBFS functions on images in RAM	2012-01-26 12:27:24 +01:00
src	northbridge/intel/i945: CHECK_SLFRCS_ON_RESUME Kconfig option	2012-01-31 14:52:22 +01:00
util	dumpmmcr: Fix compilation warnings in printf	2012-01-26 09:57:56 +01:00
.gitignore	.gitignore ectool, inteltool, msrtool, nvramtool and superiotool	2012-01-07 15:19:30 +01:00
COPYING	update license template.	2006-08-12 22:03:36 +00:00
Makefile	Prevent multiple inclusions of object files and rules	2011-10-28 21:48:55 +02:00
Makefile.inc	Change AMD vendorcode build	2011-12-02 08:59:26 +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.