coreboot-kgpe-d16/payloads/libpayload
Nico Huber 425973cf42 libpayload: Always use virtual pointers in struct sysinfo_t
We had mixed virtual and physical pointers in struct sysinfo_t. Some
being virtual by accident which led to problems when we tried to
reinitialize lib_sysinfo after relocating FILO (to get intentionally
virtual pointers valid again). I guess this didn't cause much trouble
before, as lib_get_sysinfo() was always called with physical addresses
being equal to their virtual counterparts.

For FILO, two possibilities seem practical: Either, have all pointers in
struct sysinfo_t physical, so relocation doesn't hurt. Or, have all
pointers virtual and call lib_get_sysinfo() again after relocation.

This patch goes the latter way, changing the following pointers for
situations where virtual pointers differ from physical:
  .extra_version
  .build
  .compile_time
  .compile_by
  .compile_host
  .compile_domain
  .compiler
  .linker
  .assembler
  .cb_version
  .vdat_addr
  .tstamp_table
  .cbmem_cons
  .mrc_cache
We could also just correct the accidentally virtual pointers. But, IMO,
this would lower the risk of future confusion.

Note 1: Looks like .version gets never set.

Note 2: .option_table and .framebuffer were virtual pointers but treated
        like physical ones. Even in FILO, this led to no problems as
        they were set before relocation.

Change-Id: I4c456f56f049d9f8fc40e62520b1d8ec3dad48f8
Signed-off-by: Nico Huber <nico.huber@secunet.com>
Reviewed-on: http://review.coreboot.org/1855
Tested-by: build bot (Jenkins)
Reviewed-by: Stefan Reinauer <stefan.reinauer@coreboot.org>
2012-11-15 18:51:37 +01:00
..
arch libpayload: Always use virtual pointers in struct sysinfo_t 2012-11-15 18:51:37 +01:00
bin libpayload: Don't leave temporary files behind 2012-09-28 13:43:31 +02:00
configs libpayload: Add support for the CBMEM in memory console. 2012-11-09 19:01:15 +01:00
crypto Use coreboot build system for libpayload, too. 2011-06-30 20:40:10 +02:00
curses libpayload: Enable colors in PDcurses 2011-11-11 18:24:48 +01:00
drivers libpayload: Always use virtual pointers in struct sysinfo_t 2012-11-15 18:51:37 +01:00
include libpayload: Use #ifdef for CONFIG_* checks 2012-11-15 18:51:17 +01:00
lib Discard .note sections when linking. 2012-11-07 18:30:11 +01:00
libc libpayload: Add support for the CBMEM in memory console. 2012-11-09 19:01:15 +01:00
libcbfs Refactor the endianness conversion functions and header files. 2012-11-08 19:49:51 +01:00
liblzma libpayload: Add liblzma, libcbfs 2011-08-04 08:11:21 +02:00
libpci libpayload: minor cleanups 2012-04-04 00:40:31 +02:00
sample fix compilation of hello.elf example payload. 2010-08-28 23:23:47 +00:00
util Respect linker order 2011-12-21 16:27:01 +01:00
Config.in libpayload: Add an option to skip console initialization on startup. 2012-11-09 22:55:38 +01:00
Doxyfile Run doxygen -u on doxygen configuration files 2010-06-28 10:40:38 +00:00
LICENSES Since some people disapprove of white space cleanups mixed in regular commits 2010-04-27 06:56:47 +00:00
Makefile Fixes to the libpayload build system 2011-07-03 14:47:48 +02:00
Makefile.inc libpayload: Use EXTRA_CFLAGS for additional GCC options 2012-11-12 19:14:58 +01:00
README Update repo path in libpayload readme. 2011-03-29 19:29:01 +00:00

README

-------------------------------------------------------------------------------
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
------------

 $ svn co svn://coreboot.org/coreboot/trunk/payloads/libpayload

 $ cd 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.