efcee767de
Non-x86 boards currently need to hardcode the position of their CBFS master header in a Kconfig. This is very brittle because it is usually put in between the bootblock and the first CBFS entry, without any checks to guarantee that it won't overlap either of those. It is not fun to debug random failures that move and disappear with tiny alignment changes because someone decided to write "ORBC1112" over some part of your data section (in a way that is not visible in the symbolized .elf binaries, only in the final image). This patch seeks to prevent those issues and reduce the need for manual configuration by making the image layout a completely automated part of cbfstool. Since automated placement of the CBFS header means we can no longer hardcode its position into coreboot, this patch takes the existing x86 solution of placing a pointer to the header at the very end of the CBFS-managed section of the ROM and generalizes it to all architectures. This is now even possible with the read-only/read-write split in ChromeOS, since coreboot knows how large that section is from the CBFS_SIZE Kconfig (which is by default equal to ROM_SIZE, but can be changed on systems that place other data next to coreboot/CBFS in ROM). Also adds a feature to cbfstool that makes the -B (bootblock file name) argument on image creation optional, since we have recently found valid use cases for CBFS images that are not the first boot medium of the device (instead opened by an earlier bootloader that can already interpret CBFS) and therefore don't really need a bootblock. BRANCH=None BUG=None TEST=Built and booted on Veyron_Pinky, Nyan_Blaze and Falco. Change-Id: Ib715bb8db258e602991b34f994750a2d3e2d5adf Signed-off-by: Patrick Georgi <pgeorgi@chromium.org> Original-Commit-Id: e9879c0fbd57f105254c54bacb3e592acdcad35c Original-Change-Id: Ifcc755326832755cfbccd6f0a12104cba28a20af Original-Signed-off-by: Julius Werner <jwerner@chromium.org> Original-Reviewed-on: https://chromium-review.googlesource.com/229975 Reviewed-on: http://review.coreboot.org/9620 Tested-by: build bot (Jenkins) Reviewed-by: Stefan Reinauer <stefan.reinauer@coreboot.org> |
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.. | ||
arch | ||
bin | ||
configs | ||
crypto | ||
curses | ||
drivers | ||
gdb | ||
include | ||
libc | ||
libcbfs | ||
liblzma | ||
libpci | ||
sample | ||
tests | ||
util | ||
Config.in | ||
Doxyfile | ||
LICENSES | ||
LICENSE_GPL | ||
Makefile | ||
Makefile.inc | ||
README |
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 ------------ $ 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.