Files
system76-coreboot/payloads/libpayload
Jacob Garber 768db4f5ca libpayload/libc: Correct strlcat return value
The documented return value for strlcat is horribly wrong, as is the
return value itself. It should not return the number of appended bytes,
but rather the length of the concatenated string. From the man page:

    The strlcpy() and strlcat() functions return the total length of the
    string they tried to create. For strlcpy() that means the length of
    src. For strlcat() that means the initial length of dst plus the
    length of src. While this may seem somewhat confusing, it was done
    to make truncation detection simple.

This change is more likely to fix existing code than break it, since
anyone who uses the return value of strlcat will almost certainly rely
on the standard behaviour rather than investigate coreboot's source code
to see that we have a quirky version.

Change-Id: I4421305af85bce88d12d6fdc2eea6807ccdcf449
Signed-off-by: Jacob Garber <jgarber1@ualberta.ca>
Reviewed-on: https://review.coreboot.org/c/coreboot/+/33787
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
Reviewed-by: Julius Werner <jwerner@chromium.org>
2019-07-23 09:09:32 +00:00
..
2019-04-05 22:37:19 +00:00
2019-07-09 13:05:53 +00:00
2015-06-08 00:55:07 +02:00
2019-06-04 14:14:58 +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

 $ make install (optional, will install into ./install per default)

On x86 systems, libpayload will always be 32-bit even if your host OS runs
in 64-bit, so you might have to install the 32-bit libgcc version.
On Debian systems you'd do 'apt-get install gcc-multilib' for example.

Run 'make distclean' before switching boards. This command will remove
your current .config file, so you need 'make menuconfig' again or
'make defconfig' in order to set up configuration. Default configuration
is based on 'configs/defconfig'. See the configs/ directory for examples
of configuration.


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.