coreboot/payloads/libpayload
Julius Werner f7f6f008f7 libpayload: usbhub: Don't clear PSC unless it was set
The current USB hub code always clears the port status change after
checking it, regardless of whether it was set in the first place. Since
this check runs on every poll, it might create a race condition where
the port status changes right between the GET_PORT_STATUS and the
CLEAR_FEATURE(C_PORT_CONNECT), thus clearing the statrus change flag
before it was ever read. Let's add one extra if() to avoid that possible
headache.

BUG=chrome-os-partner:21969
TEST=None

Change-Id: Idd46c2199dc6c240bd9ef068fbe70cccc88bac42
Signed-off-by: Julius Werner <jwerner@chromium.org>
Reviewed-on: https://chromium-review.googlesource.com/168098
2013-09-16 19:38:40 +00:00
..
arch arm: libpayload: Make cache invalidation take pointers instead of integers 2013-08-29 22:48:54 +00:00
bin libpayload: Change CONFIG_* to CONFIG_LP_* in the kconfig. 2013-08-14 17:05:33 -07:00
configs libpayload: Port usb hub driver to use the generic code 2013-09-16 19:38:33 +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: usbhub: Don't clear PSC unless it was set 2013-09-16 19:38:40 +00:00
include libpayload: usb: Add interval attribute to endpoints 2013-09-16 19:38:27 +00:00
libc libpayload: ehci: Cache management is hard, let's go copying... 2013-09-14 01:31:18 +00:00
libcbfs cbfs: Fix overwalk on file scan 2013-08-19 17:29:35 -07:00
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_* to CONFIG_LP_* in the kconfig. 2013-08-14 17:05:33 -07:00
util libpayload: Change CONFIG_* to CONFIG_LP_* in the kconfig. 2013-08-14 17:05:33 -07:00
Config.in libpayload: Fill gaps in the xHCI driver 2013-09-16 19:38:36 +00:00
Doxyfile Run doxygen -u on doxygen configuration files 2010-06-28 10:40:38 +00:00
LICENSES Since some people disapprove of white space cleanups mixed in regular commits 2010-04-27 06:56:47 +00:00
Makefile libpayload: Change CONFIG_* to CONFIG_LP_* in the kconfig. 2013-08-14 17:05:33 -07:00
Makefile.inc libpayload: Change CONFIG_* to CONFIG_LP_* in the kconfig. 2013-08-14 17:05:33 -07:00
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.