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Duncan Laurie 55864eff92 ACPI: Add support for runtime config TDP down
The required power MSRs are mirrored in MCHBAR so
it is possible to configure TDP at runtime via ASL.

This adds the required fields and a set of methods to
configure "TDP down" and "TDP nominal".  It explicitly
does not support "TDP up" at the moment.

PSSS: method is added to assist in searching the _PSS
table for the appropriate entry that corresponds to the
desired max non-turbo ratio.

STND: Set TDP Down from Nominal.  This will limit CPU to
the TDP down configuration by sequencing the required
changes in the right order.

STDN: Set TDP Nominal from Down.  This will set the CPU
back to nominal configuration by sequencing the required
changes in the correct (reverse) order.

This does not introduce any functional changes and must
be paired with additional changes to be useful.

The current configured TDP can be checked to see that
the transition to/from a desired level is successful.

> mmio_read8 0xfed15f50
0x00  # TDP-Nominal

> mmio_read8 0xfed15f50
0x01  # TDP-Down

Change-Id: I31a2f30cc9d134cc5eee980ae9288ae45e71c6e6
Signed-off-by: Duncan Laurie <dlaurie@chromium.org>
Reviewed-on: http://review.coreboot.org/1344
Tested-by: build bot (Jenkins)
Reviewed-by: Ronald G. Minnich <rminnich@gmail.com>
2012-07-26 20:33:06 +02:00
3rdparty@f933fda790 Finally update 3rdparty 2012-07-19 13:58:02 +02:00
documentation Whitespace/typo/cosmetic fixes (trivial). 2010-09-23 18:48:27 +00:00
payloads libpayload: Add reset function for OHCI USB driver 2012-07-12 10:00:17 +02:00
src ACPI: Add support for runtime config TDP down 2012-07-26 20:33:06 +02:00
util ifdtool: Use perror for file write errors 2012-07-24 10:13:33 +02:00
.gitignore romcc: kill gcc warnings and .gitignore generated files 2012-02-07 22:34:42 +01:00
.gitmodules Add 3rdparty as submodule 2012-05-01 00:08:37 +02:00
COPYING update license template. 2006-08-12 22:03:36 +00:00
Makefile Keep cscope.out when distclean. 2012-03-31 12:06:10 +02:00
Makefile.inc abuild: Build boards in parallel if possible 2012-05-10 22:11:16 +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.