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Sol Boucher e3260a042f cbfstool: Restructure around support for reading/writing portions of files
The buffer API that cbfstool uses to read and write files only directly supports
one-shot operations on whole files. This adds an intermediate partitioned_file
module that sits on top of the buffer system and has an awareness of FMAP
entries. It provides an easy way to get a buffer for an individual region of a
larger image file based on FMAP section name, as well as incrementally write
those smaller buffers back to the backing file at the appropriate offset. The
module has two distinct modes of operation:
- For new images whose layout is described exclusively by an FMAP section, all
the aforementioned functionality will be available.
- For images in the current format, where the CBFS master header serves as the
root of knowledge of the image's size and layout, the module falls back to a
legacy operation mode, where it only allows manipulation of the entire image
as one unit, but exposes this support through the same interface by mapping
the region named SECTION_NAME_PRIMARY_CBFS ("COREBOOT") to the whole file.

The tool is presently only ported onto the new module running in legacy mode:
higher-level support for true "partitioned" images will be forthcoming. However,
as part of this change, the crusty cbfs_image_from_file() and
cbfs_image_write_file() abstractions are removed and replaced with a single
cbfs_image function, cbfs_image_from_buffer(), as well as centralized image
reading/writing directly in cbfstool's main() function. This reduces the
boilerplate required to implement each new action, makes the create action much
more similar to the others, and will make implementing additional actions and
adding in support for the new format much easier.

BUG=chromium:470407
TEST=Build panther and nyan_big coreboot.rom images with and without this patch
and diff their hexdumps. Ensure that no differences occur at different locations
from the diffs between subsequent builds of an identical source tree. Then flash
a full new build onto nyan_big and watch it boot normally.
BRANCH=None

Change-Id: I25578c7b223bc8434c3074cb0dd8894534f8c500
Signed-off-by: Sol Boucher <solb@chromium.org>
Original-Commit-Id: 7e1c96a48e7a27fc6b90289d35e6e169d5e7ad20
Original-Change-Id: Ia4a1a4c48df42b9ec2d6b9471b3a10eb7b24bb39
Original-Signed-off-by: Sol Boucher <solb@chromium.org>
Original-Reviewed-on: https://chromium-review.googlesource.com/265581
Original-Reviewed-by: Aaron Durbin <adurbin@chromium.org>
Reviewed-on: http://review.coreboot.org/10134
Tested-by: build bot (Jenkins)
Reviewed-by: Patrick Georgi <pgeorgi@google.com>
2015-05-08 20:25:20 +02:00
3rdparty 3rdparty/vboot: Add vboot 2015-05-05 22:49:34 +02:00
Documentation Rename documentation -> Documentation 2015-05-06 19:09:47 +02:00
payloads libpayload: Guard PCI using code appropriately in XHCI driver 2015-05-04 22:21:17 +02:00
src fmaptool: Introduce the fmd ("flashmap descriptor") language and compiler 2015-05-08 19:55:42 +02:00
util cbfstool: Restructure around support for reading/writing portions of files 2015-05-08 20:25:20 +02:00
.gitignore fmaptool: Introduce the fmd ("flashmap descriptor") language and compiler 2015-05-08 19:55:42 +02:00
.gitmodules 3rdparty/vboot: Add vboot 2015-05-05 22:49:34 +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
MAINTAINERS MAINTAINERS: Add lint scripts 2015-05-07 19:41:22 +02:00
Makefile make: support absolute and relative obj= specifications 2015-05-08 19:47:11 +02:00
Makefile.inc fmaptool: Introduce the fmd ("flashmap descriptor") language and compiler 2015-05-08 19:55:42 +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 vboot: split class in library and stage 2015-04-30 15:39:53 +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.