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Julius Werner 6af43804c5 libpayload: usb: Try to avoid reusing device addresses
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>
2014-12-22 21:44:43 +01:00
3rdparty@a8b0c52850 3dparty: Update to latest commit in blobs repository 2014-12-22 06:19:28 +01:00
documentation mkelfimage: remove 2014-10-08 14:27:24 +02:00
payloads libpayload: usb: Try to avoid reusing device addresses 2014-12-22 21:44:43 +01:00
src hp/pavilion_m6_1035dx: Enable IOMMU 2014-12-22 16:33:29 +01:00
util util: Remove 'getpir' and 'mptable' tools 2014-12-19 21:15:18 +01:00
.gitignore .gitignore: add the doxygen directory. 2014-12-14 23:30:45 +01:00
.gitmodules nvidia/cbootimage: avoid upstream's build system 2014-10-02 10:26:58 +02:00
.gitreview
COPYING
Makefile Makefile: Tone down some clang warnings, some are unproductive 2014-12-12 13:29:47 +01:00
Makefile.inc build system: allow defining alignment for cbfs-files 2014-12-19 19:02:57 +01:00
README
toolchain.inc Add UCB RISCV support for architecture, soc, and emulation mainboard.. 2014-12-01 19:06:43 +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
------------------

 * gcc / g++
 * make

Optional:

 * doxygen (for generating/viewing documentation)
 * iasl (for targets with ACPI support)
 * gdb (for better debugging facilities on some targets)
 * ncurses (for 'make menuconfig')
 * 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.