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Aaron Durbin 0dff57dd7a cbmem: switch over to imd-based cbmem
By design, the imd library still provdes dynamic growth so that
feature is consistent.  The imd-based cbmem packs small allocations
into a larger entry using a tiered imd. The following examples show
the reduced fragmentation and reduced memory usage.

Before with dynamic cbmem:
CBMEM ROOT  0. 023ff000 00001000
aaaabbbb    1. 023fe000 00001000
aaaabbbc    2. 023fd000 00001000
aaaabbbe    3. 023fc000 00001000
aaaacccc    4. 023fa000 00002000
aaaacccd    5. 023f9000 00001000
ROMSTAGE    6. 023f8000 00001000
CONSOLE     7. 023d8000 00020000
COREBOOT    8. 023d6000 00002000

After with tiered imd:
IMD ROOT    0. 023ff000 00001000
IMD SMALL   1. 023fe000 00001000
aaaacccc    2. 023fc000 00001060
aaaacccd    3. 023fb000 000007cf
CONSOLE     4. 023db000 00020000
COREBOOT    5. 023d9000 00002000
IMD small region:
  IMD ROOT    0. 023fec00 00000400
  aaaabbbb    1. 023febe0 00000020
  aaaabbbc    2. 023feba0 00000040
  aaaabbbe    3. 023feb20 00000080
  ROMSTAGE    4. 023feb00 00000004

Side note: this CL provides a basis for what hoops one needs to
jump through when there are not writeable global variables on
a particular platform in the early stages.

Change-Id: If770246caa64b274819e45a26e100b62b9f8d2db
Signed-off-by: Aaron Durbin <adurbin@chromium.org>
Reviewed-on: http://review.coreboot.org/9169
Tested-by: build bot (Jenkins)
Reviewed-by: Marc Jones <marc.jones@se-eng.com>
2015-04-22 22:56:31 +02:00
3rdparty@892a6976ba 3rdparty: move checkout marker forward 2015-04-14 01:09:51 +02:00
documentation documentation: define downstream data consumption rules 2015-04-07 00:20:13 +02:00
payloads arm64: Add arch_program_segment_loaded call to arm64 2015-04-22 08:56:36 +02:00
src cbmem: switch over to imd-based cbmem 2015-04-22 22:56:31 +02:00
util cbmem: switch over to imd-based cbmem 2015-04-22 22:56:31 +02:00
.gitignore .gitignore: add the doxygen directory. 2014-12-14 23:30:45 +01:00
.gitmodules nvidia/cbootimage: avoid upstream's build system 2014-10-02 10:26:58 +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 Makefile: Disable implicit rules 2015-04-22 08:41:54 +02:00
Makefile.inc broadcom/cygnus: add secimage and sign bootblock 2015-04-22 08:59:18 +02:00
README Update README with newer version of the text from the web page 2011-06-15 10:16:33 +02:00
toolchain.inc ARM: Remove -mno-unaligned-access 2015-04-17 09:21:16 +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.