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Aaron Durbin bb4e79a332 x86: add new mtrr implementation
The old MTRR code had issues using too many variable
MTRRs depending on the physical address space layout dictated
by the device resources. This new implementation calculates
the default MTRR type by comparing the number of variable MTRRs
used for each type. This avoids the need for IORESOURE_UMA_FB
because in many of those situations setting the default type to WB
frees up the variable MTTRs to set that space to UC.

Additionally, it removes the need for IORESOURCE_IGNORE_MTRR
becuase the new mtrr uses the memrange library which does merging
of resources.

Lastly, the sandybridge gma has its speedup optimization removed
for the graphics memory by writing a pre-determined MTRR index.
That will be fixed in an upcoming patch once write-combining support
is added to the resources.

Slight differences from previous MTRR code:
- The number of reserved OS MTRRs is not a hard limit. It's now advisory
  as PAT can be used by the OS to setup the regions to the caching
  policy desired.
- The memory types are calculated once by the first CPU to run the code.
  After that all other CPUs use that value.
- CONFIG_CACHE_ROM support was dropped. It will be added back in its own
  change.

A pathological case that was previously fixed by changing vendor code
to adjust the IO hole location looked like the following:

MTRR: Physical address space:
0x0000000000000000 - 0x00000000000a0000 size 0x000a0000 type 6
0x00000000000a0000 - 0x00000000000c0000 size 0x00020000 type 0
0x00000000000c0000 - 0x00000000ad800000 size 0xad740000 type 6
0x00000000ad800000 - 0x00000000d0000000 size 0x22800000 type 0
0x00000000d0000000 - 0x00000000e0000000 size 0x10000000 type 1
0x00000000e0000000 - 0x0000000100000000 size 0x20000000 type 0
0x0000000100000000 - 0x000000014f600000 size 0x4f600000 type 6

As noted by the output below it's impossible to accomodate those
ranges even with 10 variable MTRRS. However, because the code
can select WB as the default MTRR type it can be done in 6 MTRRs:

MTRR: default type WB/UC MTRR counts: 6/14.
MTRR: WB selected as default type.
MTRR: 0 base 0x00000000ad800000 mask 0x0000007fff800000 type 0
MTRR: 1 base 0x00000000ae000000 mask 0x0000007ffe000000 type 0
MTRR: 2 base 0x00000000b0000000 mask 0x0000007ff0000000 type 0
MTRR: 3 base 0x00000000c0000000 mask 0x0000007ff0000000 type 0
MTRR: 4 base 0x00000000d0000000 mask 0x0000007ff0000000 type 1
MTRR: 5 base 0x00000000e0000000 mask 0x0000007fe0000000 type 0

Change-Id: Idfcc78d9afef9d44c769a676716aae3ff2bd79de
Signed-off-by: Aaron Durbin <adurbin@chromium.org>
Reviewed-on: http://review.coreboot.org/2889
Tested-by: build bot (Jenkins)
Reviewed-by: Stefan Reinauer <stefan.reinauer@coreboot.org>
2013-03-29 19:53:43 +01:00
3rdparty@ba8caa30bd Update 3rdparty mark to latest repository 2013-03-15 19:09:08 +01:00
documentation sconfig: rename lapic_cluster -> cpu_cluster 2013-02-14 07:07:20 +01:00
payloads libpayload: Fix prototype warnings in PDCurses 2013-03-26 19:37:33 +01:00
src x86: add new mtrr implementation 2013-03-29 19:53:43 +01:00
util crossgcc: Fix building with texinfo-5.x 2013-03-28 21:14:50 +01:00
.gitignore add a few entries to .gitignore 2013-01-10 22:51:20 +01:00
.gitmodules gitmodules: Ignore 3rdparty in "diff family" 2013-03-16 04:07:14 +01:00
.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 rmodule: add rmodules class and new type 2013-03-18 20:46:40 +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.