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This patch switches every last part of Coreboot on ARM over to Thumb mode: libpayload, the internal libgcc, and assorted assembly files. In combination with the respective depthcharge patch, this will switch to Thumb mode right after the entry point of the bootblock and not switch back to ARM until the final assembly stub that jumps to the kernel. The required changes to make this work include some new headers and Makefile flags to handle assembly files (using the unified syntax and the same helper macros as Linux), modifying our custom-written libgcc code for 64-bit division to support Thumb (removing some stale old files that were never really used for clarity), and flipping the general CFLAGS to Thumb (some more cleanup there as well while I'm at it). BUG=None TEST=Snow and Nyan still boot. Original-Change-Id: I80c04281e3adbf74f9f477486a96b9fafeb455b3 Original-Signed-off-by: Julius Werner <jwerner@chromium.org> Original-Reviewed-on: https://chromium-review.googlesource.com/182212 Original-Reviewed-by: Gabe Black <gabeblack@chromium.org> (cherry picked from commit 5f65c17cbfae165a95354146ae79e06c512c2c5a) Conflicts: payloads/libpayload/include/arm/arch/asm.h src/arch/arm/Makefile.inc src/arch/arm/armv7/Makefile.inc *** There is an issue with what to do with ramstage-S-ccopts, and *** will need to be covered in additional ARM cleanup patches. Change-Id: I80c04281e3adbf74f9f477486a96b9fafeb455b3 Signed-off-by: Marc Jones <marc.jones@se-eng.com> Reviewed-on: http://review.coreboot.org/6930 Tested-by: build bot (Jenkins) Reviewed-by: Stefan Reinauer <stefan.reinauer@coreboot.org> |
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.. | ||
arch | ||
bin | ||
configs | ||
crypto | ||
curses | ||
drivers | ||
include | ||
libc | ||
libcbfs | ||
liblzma | ||
libpci | ||
sample | ||
tests | ||
util | ||
Config.in | ||
Doxyfile | ||
LICENSES | ||
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.