Matt Delco a20e59da15 libpayload: classify all keyboards
Depthcharge uses the keyboard type to help determine whether
it can trust the keyboard for security-sensitive confirmations.
Currently it trusts anything except usb, but now there's a need
to distrust ec-based ps/2 keyboards that are associated with untrusted
ECs.  To help facilitate this, coreboot needs to report more
details about non-usb keyboards, so this change replaces the current
instances of unknown with enum values that distinguish uart and gpio
from ec-based keyboards.

BUG=b:129471321
BRANCH=None
TEST=Local compile and flash to systems with trusted and non-trusted
ECs.  Confirmed that security confirmation can't be performed via
keyboard on a system with an untrusted EC but can still be performed
on a system with a trusted EC.

Change-Id: Iee6295dafadf7cb3da98b62f43b0e184b2b69b1e
Signed-off-by: Matt Delco <delco@chromium.org>
Reviewed-on: https://review.coreboot.org/c/coreboot/+/32717
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
Reviewed-by: Julius Werner <jwerner@chromium.org>
2019-05-13 09:20:25 +00:00
..
2019-04-05 22:37:19 +00:00
2015-06-08 00:55:07 +02:00
2015-06-08 00:55:07 +02:00
2018-04-17 10:38:06 +00:00

-------------------------------------------------------------------------------
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 https://www.coreboot.org for details on coreboot.


Installation
------------

 $ git clone https://review.coreboot.org/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 https://www.coreboot.org/Libpayload.

For additional information, patches, and discussions, please join the
coreboot mailing list at https://www.coreboot.org/Mailinglist, where most
libpayload developers are subscribed.


Copyright and License
---------------------

See LICENSES.