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Ken Chang a859aa3df5 nyan*: Set GEN2 I2C pads to open-drain mode
The VDDIO to GEN2 I2C SCL/SDA pins is 1.8V and the external
pull-up voltage is 3.3V (the external 3.3V > I/O 1.8V) thus
the pinmux E_OD bit of these two pins needs to be set to
ensure GEN2 I2C pads work fine on 3.3V.

BRANCH=nyan
BUG=none
TEST=observed voltage drop from 3.3V to 2.36V on gen2 i2c
on blaze w/o this change. the waveform looks good on both
scl/sda pins w/ this change.

Original-Change-Id: I1b97f0c9c7580d1e532c3bdf7ac8690241ee7ee3
Original-Signed-off-by: Ken Chang <kenc@nvidia.com>
Original-Reviewed-on: https://chromium-review.googlesource.com/200996
Original-Reviewed-by: Julius Werner <jwerner@chromium.org>
(cherry picked from commit 2db39166ec525e56a19746f38a867305a2687365)
Signed-off-by: Marc Jones <marc.jones@se-eng.com>

Change-Id: I0c84eade89311baf0a6f180cb5cc9e2145f6b7ea
Reviewed-on: http://review.coreboot.org/7952
Tested-by: build bot (Jenkins)
Reviewed-by: Paul Menzel <paulepanter@users.sourceforge.net>
Reviewed-by: Kyösti Mälkki <kyosti.malkki@gmail.com>
2014-12-31 05:26:51 +01:00
3rdparty@a8b0c52850 3rdparty: Update to latest commit in blobs repository 2014-12-28 16:04:03 +01:00
documentation mkelfimage: remove 2014-10-08 14:27:24 +02:00
payloads libpayload: usb: xhci: Fix TD size if it overflows 5 bits 2014-12-31 04:45:43 +01:00
src nyan*: Set GEN2 I2C pads to open-drain mode 2014-12-31 05:26:51 +01:00
util cbmem: use a single id to name mapping table 2014-12-30 19:17:47 +01:00
.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
COPYING
Makefile Makefile: Tone down some clang warnings, some are unproductive 2014-12-12 13:29:47 +01:00
Makefile.inc intel: Fix UPDATE-FIT step in build 2014-12-28 19:58:59 +01:00
README
toolchain.inc Add UCB RISCV support for architecture, soc, and emulation mainboard.. 2014-12-01 19:06:43 +01:00

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.