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Alexandru Gagniuc 87c6097c8f arch/x86: Include timestamp.c in all stages
timestamp.c was not included in bootblock and postcar. This means that
these two stages would use the weak implementation in lib/timestamp.c
instead of the arch-specific implementation based on rdtsc.

This resulted in using timer_monotonic_get() which resets the
timestamps from 0. timer_monotonic_get() only provides per-stage
incrementing semantics on x86 because lapic implementation has
counting down values. A globally incrementing counter like rdtsc
provides the semantics like every other non-x86.

On the test configuration, the weak implementation of timestamp_get()
returned zero, resulting in wrong timestamps coming from the bootblock,
while romstage and ramstage used the arch implementation and returned
correct timestamps.

This is a great example of why weak functions are dangerous, and how
easy it is to miss subtle yet strong interactions between subsystems
and the coreboot buildsystem.

Change-Id: I656f9bd58a6fc179d9dbbc496c5b684ea9288eb5
Signed-off-by: Alexandru Gagniuc <alexandrux.gagniuc@intel.com>
Reviewed-on: https://review.coreboot.org/14860
Tested-by: build bot (Jenkins)
Reviewed-by: Aaron Durbin <adurbin@chromium.org>
2016-05-19 18:25:59 +02:00
3rdparty 3rdparty/blobs: add more Qualcomm stubs 2016-05-10 21:22:28 +02:00
Documentation Documentation/Intel: Update the documentation 2016-05-18 19:47:16 +02:00
payloads libpayload: cbfs: Add cbfs_handle API for more fine-grained accesses 2016-05-17 22:48:28 +02:00
src arch/x86: Include timestamp.c in all stages 2016-05-19 18:25:59 +02:00
util util/cbfstool: allow option to honor FSP modules' linked address 2016-05-18 03:19:12 +02:00
.clang-format Provide coreboot coding style formalisation file for clang-format 2015-11-10 00:49:03 +01:00
.gitignore .gitignore: add build and libpayload dirs for nvramcui payload 2016-05-03 04:16:45 +02:00
.gitmodules git modules: rename git submodules to avoid hierarchies 2016-02-11 20:55:55 +01:00
.gitreview
COPYING update license template. 2006-08-12 22:03:36 +00:00
MAINTAINERS MAINTAINERS: Add maintainer for Pineview & x4x chipsets & boards 2016-04-19 19:25:59 +02:00
Makefile Makefile: Update payload clean targets 2016-03-09 17:01:56 +01:00
Makefile.inc jenkins: Run the romcc test suite 2016-05-19 00:14:15 +02:00
README
toolchain.inc toolchain.inc: test IASL by version string instead of number 2016-03-04 16:36:25 +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
------------------

 * 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)

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 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.