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Aaron Durbin f24262d018 haswell: calibrate 24MHz clock against BCLK
On haswell ULT systems there is a 24MHz clock that continuously runs
when deep package c-states are entered. The 100MHz BCLK is shut down
in the lower c-states. When the package wakes back up a conversion
formula needs to be applied. The 24MHz calibration is done using the
internal PCODE unit.

Change-Id: I6be7702fb1de1429273724536f5af9125b98da64
Signed-off-by: Aaron Durbin <adurbin@chromium.org>
Reviewed-on: https://gerrit.chromium.org/gerrit/48292
Tested-by: Stefan Reinauer <reinauer@google.com>
Commit-Queue: Stefan Reinauer <reinauer@google.com>
Reviewed-on: http://review.coreboot.org/4136
Tested-by: build bot (Jenkins)
Reviewed-by: Alexandru Gagniuc <mr.nuke.me@gmail.com>
2013-11-24 16:03:18 +01:00
3rdparty@aebd21811d AMD Yangtze: Update 3rdparty hash for new blobs 2013-07-18 20:06:55 +02:00
documentation Remove NRV2B compression support 2013-08-31 08:58:37 +02:00
payloads libpayload: fix wrong endian assumption in sha1.c 2013-11-24 05:40:19 +01:00
src haswell: calibrate 24MHz clock against BCLK 2013-11-24 16:03:18 +01:00
util nvramtool: write size field more obviously 2013-11-19 00:59:55 +01:00
.gitignore Add GRUB2 payload to build system 2013-11-19 01:07:25 +01:00
.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
Makefile arch/x86/Makefile.inc: Pass $(AS) and $(CPP) to SeaBIOS 2013-10-17 01:59:50 +02:00
Makefile.inc sandybridge: Make build possible without descriptor.bin 2013-06-24 17:42:48 +02:00
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.