coreboot-kgpe-d16/payloads/libpayload
Julius Werner e44a4e8787 libpayload: usb: xhci: Prevent address reuse
We have been trying to avoid reassigning previously used USB addresses
to different devices since CL:197420, because some devices seem to take
issue with that. Unfortunately, that patch doesn't affect XHCI: those
controllers insist on chosing addresses on their own. The only way to
prevent them from reusing a previously assigned address is to not
disable that slot at all.

This patch implements address reuse avoidance on XHCI by not disabling
slots when a device is detatched (which may occur both on physical
detachment or if we simply couldn't find a driver for that device).
Instead, we just release as many resources as we can for detached
devices (by dropping all endpoint contexts) and defer the final cleanup
until the point where the controller actually runs out of resources (a
point that we probably don't often reach in most firmware scenarios).

BRANCH=none
BUG=chrome-os-partner:42181
TEST=Booted an Oak plugged into a Servo without having a driver for the
SMSC network chip, observed that it could still enumerate the next
device afterwards. Kept unplugging/replugging stuff until the cleanup
triggered and made sure the controller still worked after that. Also
played around a bit on a Falco without issues.

Change-Id: Idfbab39abbc5bc5eff822bedf9c8d5bd4cad8cd2
Signed-off-by: Patrick Georgi <pgeorgi@chromium.org>
Original-Commit-Id: 88c6bcbc41156729c3c38937c8a4adebc66f1ccb
Original-Change-Id: I0653a4f6a02c02498210a70ffdda9d986592813b
Original-Signed-off-by: Julius Werner <jwerner@chromium.org>
Original-Reviewed-on: https://chromium-review.googlesource.com/284175
Original-Tested-by: Nicolas Boichat <drinkcat@chromium.org>
Original-Reviewed-by: Patrick Georgi <pgeorgi@chromium.org>
Reviewed-on: http://review.coreboot.org/10957
Tested-by: build bot (Jenkins)
Reviewed-by: Stefan Reinauer <stefan.reinauer@coreboot.org>
2015-07-18 09:40:32 +02:00
..
arch cbfs: define libpayload_init_default_cbfs_media weakly 2015-07-06 09:42:12 +02:00
bin
configs libpayload: update defconfigs 2015-07-08 10:25:11 +02:00
crypto libpayload: Make Kconfig bools use IS_ENABLED() 2015-06-30 18:55:15 +02:00
curses libpayload: Make Kconfig bools use IS_ENABLED() 2015-06-30 18:55:15 +02:00
drivers libpayload: usb: xhci: Prevent address reuse 2015-07-18 09:40:32 +02:00
gdb Remove address from GPLv2 headers 2015-05-21 20:50:25 +02:00
include libpayload: usb: dwc2: support split transaction 2015-07-16 22:39:59 +02:00
libc libpayload: store boot media information in sysinfo 2015-07-14 22:37:10 +02:00
libcbfs libpayload: assume cbfs file alignment is 64 byte 2015-07-15 16:34:50 +02:00
liblz4 libpayload: Add LZ4 decompression algorithm 2015-07-09 00:10:16 +02:00
liblzma lzma: Return correct amount of decompressed bytes 2015-07-06 09:40:37 +02:00
libpci Remove empty lines at end of file 2015-06-08 00:55:07 +02:00
sample Remove empty lines at end of file 2015-06-08 00:55:07 +02:00
tests Remove empty lines at end of file 2015-06-08 00:55:07 +02:00
Doxyfile
Kconfig libpayload: Add LZ4 decompression algorithm 2015-07-09 00:10:16 +02:00
LICENSES libpayload: Add LZ4 decompression algorithm 2015-07-09 00:10:16 +02:00
LICENSE_GPL
Makefile libpayload: Use top level xcompile 2015-07-09 08:47:16 +02:00
Makefile.inc libpayload: Have make install save .xcompile file 2015-07-09 08:47:41 +02:00
README Remove empty lines at end of file 2015-06-08 00:55:07 +02:00

README

-------------------------------------------------------------------------------
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.