Go to file
Julius Werner 7f70ad610b rk3288: Add software I2C support
This patch adds the necessary platform glue to allow the use of
software-driven I2C bit banging on the RK3288. This is just a debugging
feature that can be used to reproduce certain I2C failure cases.

Also fix Makefile verstage linking for the feature and add some new
rk3288 IOMUX macros as needed.

BRANCH=None
BUG=None
TEST=Added "CONFIG_SOFTWARE_I2C=y" to configs/config.veyron_jerry,
wrapped Jerry's bootblock and verstage in software_i2c_attach/detach()
calls, confirmed that both PMIC and TPM could be driven correctly with
software I2C driver. Tried out different combinations of
software_i2c_wedge_ack() and software_i2c_wedge_read() on the PMIC and
observed transfer results with the hardware controller after reboot...
the worst that would happen is that the first register read-modify-write
(DCDC_ILMAX) would fail to read, but all later transfers would be fine.
Since that register is written twice (due to current BUCK1 ramp
implementation) and is not terribily important anyway, I think we don't
need to worry about wedging problems.

Change-Id: Iba801ee61d30fb1fd3aef8300612c67fa50c441b
Signed-off-by: Patrick Georgi <pgeorgi@chromium.org>
Original-Commit-Id: 24dfca9bab38a20c40ef0c2dd4c775b8d8f47487
Original-Change-Id: I96777300a57c85471bad20e23a455551e9970222
Original-Signed-off-by: Julius Werner <jwerner@chromium.org>
Original-Reviewed-on: https://chromium-review.googlesource.com/247890
Original-Reviewed-by: Aaron Durbin <adurbin@chromium.org>
Reviewed-on: http://review.coreboot.org/9757
Tested-by: build bot (Jenkins)
Reviewed-by: Stefan Reinauer <stefan.reinauer@coreboot.org>
2015-04-17 09:59:19 +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 purin: add basic set of files for libpayload 2015-04-17 09:58:25 +02:00
src rk3288: Add software I2C support 2015-04-17 09:59:19 +02:00
util timestamps: You can never have enough of them! 2015-04-14 09:03:40 +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: Fix dependency tracking for ramstage objects 2015-04-17 09:55:31 +02:00
Makefile.inc Makefile: Fix dependency tracking for ramstage objects 2015-04-17 09:55:31 +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.