Go to file
Julius Werner ae05d095b3 bootmem: Keep OS memory map separate from the start
The patch series ending in 64049be (lib/bootmem: Add method to walk OS
POV memory tables) expanded the bootmem framework to also keep track of
memory regions that are only relevant while coreboot is still executing,
such as the ramstage code and data. Mixing this into the exsting bootmem
ranges has already caused an issue on CONFIG_RELOCATEABLE_RAMSTAGE
boards, because the ramstage code in CBMEM is marked as BM_RAMSTAGE
which ends up getting translated back to LB_RAM in the OS tables. This
was fixed in 1ecec5f (lib/bootmem: ensure ramstage memory isn't given to
OS) for this specific case, but unfortunately Arm boards can have a
similar problem where their stack space is sometimes located in an SRAM
region that should not be made available as RAM to the OS.

Since both the resources made available to the OS and the regions
reserved for coreboot can be different for each platform, we should find
a generic solution to this rather than trying to deal with each issue
individually. This patch solves the problem by keeping the OS point of
view and the coreboot-specific ranges separate from the start, rather
than cloning it out later. Ranges only relevant to the coreboot view
will never touch the OS-specific layout, to avoid the problem of losing
information about the original memory type of the underlying region that
needs to be restored for the OS view. This both supersedes the
RELOCATABLE_RAMSTAGE fix and resolves the problems on Arm boards.

Change-Id: I7bb018456b58ad9b0cfb0b8da8c26b791b487fbb
Signed-off-by: Julius Werner <jwerner@chromium.org>
Reviewed-on: https://review.coreboot.org/26182
Reviewed-by: Aaron Durbin <adurbin@chromium.org>
Reviewed-by: Nico Huber <nico.h@gmx.de>
Reviewed-by: Patrick Rudolph <patrick.rudolph@9elements.com>
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
2018-05-10 01:24:40 +00:00
3rdparty Update vboot submodule to upstream master 2018-04-26 16:35:16 +00:00
Documentation Documentation: Add HiFive Unleashed documentation 2018-05-08 03:07:36 +00:00
configs configs: Add intel/harcuvar FSP 2.0 sample configuration 2017-10-04 02:56:33 +00:00
payloads cbfs: Rename CBFS_TYPE_PAYLOAD to CBFS_TYPE_SELF 2018-05-04 10:30:24 +00:00
src bootmem: Keep OS memory map separate from the start 2018-05-10 01:24:40 +00:00
util util/lint: Ignore whitespace, newlines, and licenses in vbt files 2018-05-09 16:19:36 +00:00
.checkpatch.conf .checkpatch.conf: Ignore CORRUPTED_PATCH lint 2017-10-29 10:11:58 +00:00
.clang-format clang-format: Update .clang-format to be compliant with linux kernel coding style 2018-04-23 09:26:08 +00:00
.gitignore Documentation: Add support for building with Sphinx 2018-04-26 12:25:03 +00:00
.gitmodules
.gitreview
COPYING
MAINTAINERS MAINTAINERS: change second PC Engines maintainer 2018-03-21 18:25:49 +00:00
Makefile Makefile: Add filelist to help 2018-01-29 15:35:11 +00:00
Makefile.inc device: Include devicetree in SMM stage 2018-02-22 09:55:19 +00:00
README README: Update requirements 2017-06-27 17:04:32 +00:00
gnat.adc
toolchain.inc toolchain: Always use GCC for Ada sources 2017-09-23 10:57:40 +00:00

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 https://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:

 * https://www.coreboot.org/Supported_Motherboards
 * https://www.coreboot.org/Supported_Chipsets_and_Devices


Build Requirements
------------------

 * make
 * gcc / g++
   Because Linux distribution compilers tend to use lots of patches. coreboot
   does lots of "unusual" things in its build system, some of which break due
   to those patches, sometimes by gcc aborting, sometimes - and that's worse -
   by generating broken object code.
   Two options: use our toolchain (eg. make crosstools-i386) or enable the
   ANY_TOOLCHAIN Kconfig option if you're feeling lucky (no support in this
   case).
 * iasl (for targets with ACPI support)
 * pkg-config
 * libssl-dev (openssl)

Optional:

 * doxygen (for generating/viewing documentation)
 * gdb (for better debugging facilities on some targets)
 * ncurses (for 'make menuconfig' and 'make nconfig')
 * flex and bison (for regenerating parsers)


Building coreboot
-----------------

Please consult https://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 https://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:

  https://www.coreboot.org

You can contact us directly on the coreboot mailing list:

  https://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.