Files
system76-coreboot/payloads/libpayload
Julius Werner b4fbee9a41 libpayload: video: Make cursor fixup independent of visibility
The video console runs a video_console_fixup_cursor() function after
every printed character to make sure the cursor is still in the output
window and avoid overflows. For some crazy reason, this function does
not run when cursor_enabled is false... however, that variable is only
about cursor *visibility*, and it's imperative that we still do proper
bounds checking for our output even if the cursor itself doesn't get
displayed (otherwise we can end up overwriting malloc cookies that cause
a panic on the next free() and other fun things like that).

In fact, there seems to be no reason at all to even keep track of the
cursor visibility state in the generic video console framework (the
specific backends already do it, too), so let's remove that code
entirely. Also set the default cursor visibilty in the corebootfb
backend to 0 since that's consistent with what the other backends do.

BUG=None
TEST=Turn on video console on Big, generate enough output to make it
scroll, make sure it does not crash.

Original-Change-Id: I1201a5bccb4711b6ecfc4cf47a8ace16331501b4
Original-Signed-off-by: Julius Werner <jwerner@chromium.org>
Original-Reviewed-on: https://chromium-review.googlesource.com/196323
Original-Reviewed-by: Gabe Black <gabeblack@chromium.org>
Original-Reviewed-by: Hung-Te Lin <hungte@chromium.org>
Original-Reviewed-by: Stefan Reinauer <reinauer@chromium.org>
(cherry picked from commit 1f880bca06ed0a3f2c75abab399d32a2e51ed10e)
Signed-off-by: Marc Jones <marc.jones@se-eng.com>

Change-Id: I6c67a9efb00d96fcd67f7bc1ab55a23e78fc479e
Reviewed-on: http://review.coreboot.org/7908
Tested-by: build bot (Jenkins)
Reviewed-by: Edward O'Callaghan <eocallaghan@alterapraxis.com>
2014-12-30 19:06:20 +01:00
..
2014-09-08 18:59:23 +02:00
2014-11-13 06:22:25 +01:00
2014-08-10 22:25:07 +02:00
2012-04-04 00:40:31 +02:00

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