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Duncan Laurie ddf68901f7 peppy: Enable power limiting for thermal control
Limit power to 12W at 73C and remove limit at 68C.

To have the CPU consume maximum power it is necessary to stress
both the CPU and the GPU.  Bastion (chrome.supergiantgames.com)
and/or webglsamples.googlecode.com can be useful for this.

Testing this properly requires a script to report the running
average power readings.  The watch_power.sh script is attached
to this issue in the partner tracker.

1) Run watch_power.sh continuously:
localhost ~ # watch -n 0 bash -e /tmp/watch_power.sh
2) Start Bastion (or other stress apps).  The power draw should
be close to 15W if under enough load.
3) Watch until temperature climbs above 73C and is caught by
the thermal zone 10 second poll, this can be sped up by blocking
or removing the fan.
4) The ACPI thermal zone states should change to reflect that
active[2] is now enabled and power consumption should drop to 12W.
5) Stop the stress apps and wait until the CPU cools off again,
enable the fan again if it was removed.
6) The ACPI thermal zone state should switch back to active[3].

Change-Id: Ie6714a8543d4f06edf8513086fc9c968273bdb23
Signed-off-by: Duncan Laurie <dlaurie@chromium.org>
Reviewed-on: https://gerrit.chromium.org/gerrit/60545
Reviewed-on: http://review.coreboot.org/4335
Tested-by: build bot (Jenkins)
Reviewed-by: Alexandru Gagniuc <mr.nuke.me@gmail.com>
2013-12-07 03:28:48 +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 Do not export variables to GRUB build 2013-12-06 16:38:51 +01:00
src peppy: Enable power limiting for thermal control 2013-12-07 03:28:48 +01:00
util abuild: fix and enable USE_XARGS configuration 2013-12-05 20:46:00 +01:00
.gitignore .gitignore: Properly ignore KDevelop files 2013-11-25 02:12:58 +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 update license template. 2006-08-12 22:03:36 +00:00
Makefile arch/x86/Makefile.inc: Pass $(AS) and $(CPP) to SeaBIOS 2013-10-17 01:59:50 +02:00
Makefile.inc Fix build with USE_OPTION_TABLE 2013-12-01 23:15:08 +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.