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Marc Jones 29922a5409 soc/amd/stoneyridge: Wait for UART to be ready
The Stoney Ridge UART and AMBA devices must be powered and report power
and clock OK prior to using the coreboot serial console. The code used
to have a delay to wait for the power and clock, but didn't check the
OK bits. This caused long delays on a reboot, as each byte would time out
until the console was reset again at romstage.

This change also removes the UART reset. The device has just been
powered and is in reset already. Testing indicates the reset isn't
needed.

BUG=b:65853981
TEST=Boot to Chrome OS, run the reboot command, verify that the long
delay is gone.

Change-Id: I410700df5df255d20b8e5d192c72241dd44cf676
Signed-off-by: Marc Jones <marcj303@gmail.com>
Reviewed-on: https://review.coreboot.org/21731
Reviewed-by: Aaron Durbin <adurbin@chromium.org>
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
2017-10-03 17:56:37 +00:00
3rdparty Update vboot submodule to upstream master 2017-09-13 02:24:37 +00:00
Documentation Documentation: Update Lesson2.md 2017-09-05 03:54:54 +00:00
configs configs: Add intel/galileo test configurations 2017-06-20 18:10:47 +02:00
payloads payloads/external: Clone GRUB2 over HTTPS 2017-09-16 22:33:29 +00:00
src soc/amd/stoneyridge: Wait for UART to be ready 2017-10-03 17:56:37 +00:00
util util/cbmem: fix feedback for 'be explicit about memory map sizes' 2017-10-02 17:16:14 +00:00
.checkpatch.conf Fix files with multiple newlines at the end. 2017-07-24 15:08:08 +00:00
.clang-format
.gitignore copy & update test routines from what-jenkins-does 2017-08-11 15:24:56 +00:00
.gitmodules Set up 3rdparty/libgfxinit 2016-10-29 01:35:03 +02:00
.gitreview
COPYING
MAINTAINERS MAINTAINERS: Remove extra unnecessary space 2017-09-15 04:29:29 +00:00
Makefile toolchain: Always use GCC for Ada sources 2017-09-23 10:57:40 +00:00
Makefile.inc Makefile.inc: Remove -gnatg from ADAFLAGS_common 2017-09-23 10:50:45 +00:00
README README: Update requirements 2017-06-27 17:04:32 +00:00
gnat.adc gnat.adc: Do not generate assertion code for Refined_Post 2016-10-29 01:33:31 +02:00
toolchain.inc toolchain: Always use GCC for Ada sources 2017-09-23 10:57:40 +00:00

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 https://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:

 * https://www.coreboot.org/Supported_Motherboards
 * https://www.coreboot.org/Supported_Chipsets_and_Devices


Build Requirements
------------------

 * make
 * gcc / g++
   Because Linux distribution compilers tend to use lots of patches. coreboot
   does lots of "unusual" things in its build system, some of which break due
   to those patches, sometimes by gcc aborting, sometimes - and that's worse -
   by generating broken object code.
   Two options: use our toolchain (eg. make crosstools-i386) or enable the
   ANY_TOOLCHAIN Kconfig option if you're feeling lucky (no support in this
   case).
 * iasl (for targets with ACPI support)
 * pkg-config
 * libssl-dev (openssl)

Optional:

 * doxygen (for generating/viewing documentation)
 * gdb (for better debugging facilities on some targets)
 * ncurses (for 'make menuconfig' and 'make nconfig')
 * flex and bison (for regenerating parsers)


Building coreboot
-----------------

Please consult https://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 https://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:

  https://www.coreboot.org

You can contact us directly on the coreboot mailing list:

  https://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.