coreboot/payloads/libpayload
Furquan Shaikh 561bdd746c libpayload EHCI: Add memory barrier to EHCI driver
EHCI driver accesses mmio space using regular struct pointers. In order to avoid
any CPU re-ordering, memory barrier is required in async_set_schedule,
especially for arm64. Without the memory barrier, there seems to be re-ordering
taking place which leads to USB errors with some flash drives as well as
transfer errors in netboot.

BUG=chrome-os-partner:31533
BRANCH=None
TEST=With the memory barrier introduced, netboot for ryu completes transfer
without any error and finishes within 6-7 seconds.

Change-Id: Ic05d47422312a1cddbebe3180f4f159853604440
Signed-off-by: Furquan Shaikh <furquan@google.com>
Reviewed-on: https://chromium-review.googlesource.com/213917
Reviewed-by: Aaron Durbin <adurbin@chromium.org>
Tested-by: Furquan Shaikh <furquan@chromium.org>
Commit-Queue: Furquan Shaikh <furquan@chromium.org>
2014-08-26 03:06:01 +00:00
..
arch Consolidate coreboot table parsing 2014-08-06 08:01:28 +00:00
bin libpayload: Add support for arm64 in libpayload 2014-06-07 01:28:57 +00:00
configs auron: Enable XHCI mode by default 2014-08-26 03:05:53 +00:00
crypto libpayload: Change CONFIG_* to CONFIG_LP_* in the kconfig. 2013-08-14 17:05:33 -07:00
curses libpayload: Change CONFIG_* to CONFIG_LP_* in the kconfig. 2013-08-14 17:05:33 -07:00
drivers libpayload EHCI: Add memory barrier to EHCI driver 2014-08-26 03:06:01 +00:00
gdb libpayload: Let GDB stub read/write memory with aligned MMIO words 2014-07-22 01:24:00 +00:00
include libpayload: Add support for memory barriers 2014-08-26 03:05:57 +00:00
libc Consolidate coreboot table parsing 2014-08-06 08:01:28 +00:00
libcbfs libpayload: Fix pointer related casts 2014-05-14 00:25:48 +00:00
liblzma libpayload: Make lzma truncation non-fatal. 2013-08-19 19:04:35 -07:00
libpci libpayload: minor cleanups 2012-04-04 00:40:31 +02:00
sample fix compilation of hello.elf example payload. 2010-08-28 23:23:47 +00:00
tests libpayload: Change CONFIG_X86_SERIAL_CONSOLE to CONFIG_8250_SERIAL_CONSOLE 2013-09-27 14:05:53 +00:00
util libpayload: Add support for arm64 in libpayload 2014-06-07 01:28:57 +00:00
Config.in libpayload: Support board veyron 2014-07-02 00:47:36 +00:00
Doxyfile Run doxygen -u on doxygen configuration files 2010-06-28 10:40:38 +00:00
LICENSE_GPL libpayload: Introduce new Kconfig to explicitly allow GPL code 2014-06-13 20:37:29 +00:00
LICENSES libpayload: Introduce new Kconfig to explicitly allow GPL code 2014-06-13 20:37:29 +00:00
Makefile libpayload: Add support for arm64 in libpayload 2014-06-07 01:28:57 +00:00
Makefile.inc libpayload: Add remote GDB support 2014-06-11 03:33:56 +00:00
README libpayload, superiotool: README: Prepend coreboot/ to path of change directory line 2013-04-04 17:22:15 +02:00

-------------------------------------------------------------------------------
libpayload README
-------------------------------------------------------------------------------

libpayload is a minimal library to support standalone payloads
that can be booted with firmware like coreboot. It handles the setup
code, and provides common C library symbols such as malloc() and printf().

Note: This is _not_ a standard library for use with an operating system,
rather it's only useful for coreboot payload development!
See http://coreboot.org for details on coreboot.


Installation
------------

 $ git clone http://review.coreboot.org/p/coreboot.git

 $ cd coreboot/payloads/libpayload

 $ make menuconfig

 $ make

 $ sudo make install (optional, will install into /opt per default)

As libpayload is for 32bit x86 systems only, you might have to install the
32bit libgcc version, otherwise your payloads will fail to compile.
On Debian systems you'd do 'apt-get install gcc-multilib' for example.


Usage
-----

Here's an example of a very simple payload (hello.c) and how to build it:

 #include <libpayload.h>

 int main(void)
 {
     printf("Hello, world!\n");
     return 0;
 }

Building the payload using the 'lpgcc' compiler wrapper:

 $ lpgcc -o hello.elf hello.c

Please see the sample/ directory for details.


Website and Mailing List
------------------------

The main website is http://www.coreboot.org/Libpayload.

For additional information, patches, and discussions, please join the
coreboot mailing list at http://coreboot.org/Mailinglist, where most
libpayload developers are subscribed.


Copyright and License
---------------------

See LICENSES.