6af43804c5
We recently changed the USB stack to detach devices aggressively that we don't intend to use. This alone is not really a problem, but it exarcerbates the fact that our device detachment itself is not very good. We destroy any local info about the device, but we don't properly disable the offending port. The device keeps thinking that it's active, and if we later try to reuse that device address for another device things become confused. The real fix would be to properly disable all ports that we don't intend to use. Unfortunately, this isn't really possible in our current device/hub polymorphism structure, and I don't want to hack a new disable_port() callback into usbdev_t that really doesn't belong there. We will only be able to fix this cleanly after we ported all root hubs to the generic_hub interface. Until then, an easy workaround is to just avoid reusing addresses as long as possible. This is firmware, so the chance that we'll ever run through 127 devices is really small in practice. Even if we ever fix the underlying issue, it's probably a smart precaution to keep. BRANCH=nyan,rambi BUG=chrome-os-partner:28328 TEST=Boot from a hub that has an "unknown" device in an earlier port than the stick you want to boot from, make sure you can still boot. Original-Change-Id: I9b522dd8cbcd441e8c3b8781fcecd2effa0f23ee Original-Signed-off-by: Julius Werner <jwerner@chromium.org> Original-Reviewed-on: https://chromium-review.googlesource.com/197420 Original-Reviewed-by: Shawn Nematbakhsh <shawnn@chromium.org> Original-Reviewed-by: David Hendricks <dhendrix@chromium.org> (cherry picked from commit 28b48aa69b55a983226edf2ea616f33cd4b959e2) Signed-off-by: Marc Jones <marc.jones@se-eng.com> Change-Id: Id4c5c92e75d6b5a7e8f0ee3e396c69c4efd13176 Reviewed-on: http://review.coreboot.org/7881 Tested-by: build bot (Jenkins) Reviewed-by: Patrick Georgi <pgeorgi@google.com> |
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.. | ||
arch | ||
bin | ||
configs | ||
crypto | ||
curses | ||
drivers | ||
include | ||
libc | ||
libcbfs | ||
liblzma | ||
libpci | ||
sample | ||
tests | ||
util | ||
Config.in | ||
Doxyfile | ||
LICENSES | ||
Makefile | ||
Makefile.inc | ||
README |
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.