d13e2c4ab7
This patch represents a major overhaul of the USB enumeration code in order to make it cleaner and much more robust to weird or malicious devices. The main improvement is that it correctly parses the USB descriptors even if there are unknown descriptors interspersed within, which is perfectly legal and in particular present on all SuperSpeed devices (due to the SuperSpeed Endpoint Companion Descriptor). In addition, it gets rid of the really whacky and special cased get_descriptor() function, which would read every descriptor twice whether it made sense or not. The new code makes the callers allocate descriptor memory and only read stuff twice when it's really necessary (i.e. the device and configuration descriptors). Finally, it also moves some more responsibilities into the controller-specific set_address() function in order to make sure things are initialized at the same stage for all controllers. In the new model it initializes the device entry (which zeroes the endpoint array), sets up endpoint 0 (including MPS), sets the device address and finally returns the whole usbdev_t structure with that address correctly set. Note that this should make SuperSpeed devices work, but SuperSpeed hubs are a wholly different story and would require a custom hub driver (since the hub descriptor and port status formats are different for USB 3.0 ports, and the whole issue about the same hub showing up as two different devices on two different ports might present additional challenges). The stack currently just issues a warning and refuses to initialize this part of the hub, which means that 3.0 devices connected through a 3.0 hub may not work correctly. Change-Id: Ie0b82dca23b7a750658ccc1a85f9daae5fbc20e1 Signed-off-by: Julius Werner <jwerner@chromium.org> Reviewed-on: https://chromium-review.googlesource.com/170666 Reviewed-by: Kees Cook <keescook@chromium.org> (cherry picked from commit ecec80e062f7efe32a9a17479dcf8cb678a4a98b) Signed-off-by: Isaac Christensen <isaac.christensen@se-eng.com> Reviewed-on: http://review.coreboot.org/6780 Tested-by: build bot (Jenkins)
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libpayload README
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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
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$ 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
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See LICENSES.