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David Hendricks 1101a71219 spi: add Kconfig variable for dual-output read enable
Add a Kconfig variable so that driver code knows whether
or not to use dual-output reads.

Signed-off-by: David Hendricks <dhendrix@chromium.org>

Old-Change-Id: I31d23bfedd91521d719378ec573e33b381ebd2c5
Reviewed-on: https://chromium-review.googlesource.com/177834
Reviewed-by: David Hendricks <dhendrix@chromium.org>
Commit-Queue: David Hendricks <dhendrix@chromium.org>
Tested-by: David Hendricks <dhendrix@chromium.org>
(cherry picked from commit de6869a3350041c6823427787971efc9fcf469b8)

tegra124: implement x2 mode for SPI transfers on CBFS media

This implements x2 mode when reading CBFS media over SPI.

In theory this effectively doubles our throughput, though the initial
results were almost negligibly better. Using a logic analyzer we see
a pattern of 12 clocks, ~70ns delay, 4 clocks, ~310ns delay. So if we
want to see further gains here then we'll probably need to tune AHB
arbitration and utilization to eliminate bubbles/stalls when copying
from APB DMA.

Signed-off-by: David Hendricks <dhendrix@chromium.org>

Old-Change-Id: I33d6ae30923fc42b4dc7103d029085985472cf3e
Reviewed-on: https://chromium-review.googlesource.com/177835
Reviewed-by: Tom Warren <twarren@nvidia.com>
Reviewed-by: David Hendricks <dhendrix@chromium.org>
Commit-Queue: David Hendricks <dhendrix@chromium.org>
Tested-by: David Hendricks <dhendrix@chromium.org>
(cherry picked from commit 29289223362b12e84da5cbb130f285c6b9d314cc)

nyan: turn on dual-output reads for SPI flash

Nyan's SPI chip is capable of dual-output reads, so let's use it.

Signed-off-by: David Hendricks <dhendrix@chromium.org>

Old-Change-Id: I51a97c05aa25442d8ddcc4e3e35a2507d91a64df
Reviewed-on: https://chromium-review.googlesource.com/177836
Reviewed-by: David Hendricks <dhendrix@chromium.org>
Commit-Queue: David Hendricks <dhendrix@chromium.org>
Tested-by: David Hendricks <dhendrix@chromium.org>
(cherry picked from commit 62de0889a9cfc5686800645d05e21e272e4beb5c)

Squashed three commits to enable dual output spi reads for nyan.
Also fixed the spi_xfer interface that has been updated to use bytes
instead of bits.

Change-Id: I750a177576175b297f61e1b10eac6db15e75aa6e
Signed-off-by: Isaac Christensen <isaac.christensen@se-eng.com>
Reviewed-on: http://review.coreboot.org/6909
Tested-by: build bot (Jenkins)
Reviewed-by: David Hendricks <dhendrix@chromium.org>
2014-09-17 19:56:16 +02:00
3rdparty@f37e0e64ac AMD Steppe Eagle: Update reference to BLOBs repo (3rdparty) 2014-09-01 00:37:16 +02:00
documentation Documentation: Use correct file name for the build guide in the Makefile 2014-07-04 19:03:10 +02:00
payloads libpayload: x86: Add support for catching processor exceptions. 2014-09-15 19:02:05 +02:00
src spi: add Kconfig variable for dual-output read enable 2014-09-17 19:56:16 +02:00
util cbfstool: add aarch64 as a name 2014-09-15 19:00:12 +02:00
.gitignore .gitignore: add 3 executables that can be built in util/ 2014-08-11 06:26:01 +02:00
.gitmodules nvidia-cbootimage: add submodule 2014-09-08 18:58:40 +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 ARM: Generalize armv7 as arm. 2014-09-08 18:59:23 +02:00
Makefile.inc nvidia-cbootimage: integrate into coreboot make 2014-09-10 19:34:43 +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: Generalize armv7 as arm. 2014-09-08 18:59:23 +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.