For arch/x86 the realmode part has to be located within the same 64
KiB as the reset vector. Some older intel platforms also require 4 KiB
alignment for _start16bit.
To enforce the above, and to separate required parts of .text without
matching *(.text.*) rules in linker scripts, tag the pre-C environment
assembly code with section .init directive.
Description of .init section for ELF:
This section holds executable instructions that contribute to the
process initialization code. When a program starts to run, the
system arranges to execute the code in this section before calling the
main program entry point (called main for C programs).
Change-Id: If32518b1c19d08935727330314904b52a246af3c
Signed-off-by: Kyösti Mälkki <kyosti.malkki@gmail.com>
Reviewed-on: https://review.coreboot.org/c/coreboot/+/47599
Reviewed-by: Angel Pons <th3fanbus@gmail.com>
Reviewed-by: Arthur Heymans <arthur@aheymans.xyz>
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
The min86 example SoC code along with the example mainboard
should serve as a minimal example how a buildable x86 SoC code
base can look like.
This can serve, for instance, as a basis to add new SoCs to
coreboot. Starting with a buildable commit should help with
the review of the actual code, and also avoid any regressions
when common coreboot code changes.
As the example code itself is build-tested, it should advance
with coreboot and can't rot like documentation might. It also
serves as a check what APIs need to be implemented with the
default Kconfig settings.
Change-Id: Id76ab15fe77ae3e405c43f9c8677694f178be112
Signed-off-by: Nico Huber <nico.h@gmx.de>
Reviewed-on: https://review.coreboot.org/c/coreboot/+/45710
Reviewed-by: Tim Wawrzynczak <twawrzynczak@chromium.org>
Reviewed-by: Angel Pons <th3fanbus@gmail.com>
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
