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Ionela Voinescu 1c0d0c0159 pistachio: spi: use same clock edge for RX and TX
When using this mode data is received and transmitted on the same
edge of the SPFI clock, which allows for higher frequencies of
operation. In this mode the maximum supported frequency is 50Mhz.
If this mode is not enabled the maximum supported frequency is
25Mhz.

BUG=chrome-os-partner:31438
TEST=tested on Pistachio bring up board; the SPFI hardware block is
fed by the system clock (with a fixed freqency of 400 MHz).
To achieve the SPFI frequency of 50MHz the internal divider of
SPFI must be set to 64. To achieve a frequency of 25 Mhz the
internal divider must be set to 32.
A value of 64 = division by 8
A value of 32 = division by 16
BRANCH=none

Change-Id: Ifd5f739b6157b99e4c1f92b5bb72615ee610ae6c
Signed-off-by: Stefan Reinauer <reinauer@chromium.org>
Original-Commit-Id: 8b6cce616ec7926682d4eff096563acf1dfd6c65
Original-Change-Id: I337b6fcf462bcf6021ca77a8b1133cf49140ba76
Original-Signed-off-by: Ionela Voinescu <ionela.voinescu@imgtec.com>
Original-Reviewed-on: https://chromium-review.googlesource.com/241425
Original-Reviewed-by: David Hendricks <dhendrix@chromium.org>
Reviewed-on: http://review.coreboot.org/9663
Tested-by: build bot (Jenkins)
Reviewed-by: Patrick Georgi <pgeorgi@google.com>
2015-04-14 12:07:52 +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: Increase dma region size to 32MiB 2015-04-14 12:07:42 +02:00
src pistachio: spi: use same clock edge for RX and TX 2015-04-14 12:07:52 +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
Makefile build system: run linker scripts through the preprocessor 2015-04-06 19:14:00 +02:00
Makefile.inc CBFS: Correct ROM_SIZE for ARM boards, use CBFS_SIZE for cbfstool 2015-04-14 09:01:23 +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 mips: mips, not mipsel 2015-03-29 22:38:57 +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.