Change in coreboot[master]: arch/x86/boot: Jump to payload in protected mode

[Patrick Rudolph (Code Review)]

Hello build bot (Jenkins), Patrick Georgi, Martin Roth, Patrick Rudolph, Krystian Hebel,

I'd like you to reexamine a change. Please visit

https://review.coreboot.org/c/coreboot/+/30118

to look at the new patch set (#31).

Change subject: arch/x86/boot: Jump to payload in protected mode
......................................................................

arch/x86/boot: Jump to payload in protected mode

*   On ARCH_RAMSTAGE_X86_64 jump to the payload in protected mode.
*   Add a helper function to jump to arbitrary code in protected mode,
    similar to the real mode call handler.
*   Doesn't affect existing x86_32 code.
*   Add a macro to cast pointer to uint32_t that dies if it would overflow
    on conversion

Tested on QEMU Q35 using SeaBIOS as payload.
Tested on Lenovo T410 with additional x86_64 patches.

Change-Id: I6552ac30f1b6205e08e16d251328e01ce3fbfd14
Signed-off-by: Patrick Rudolph 
---
M Documentation/arch/x86/index.md
M src/arch/x86/Makefile.inc
M src/arch/x86/boot.c
A src/arch/x86/c_exit.S
M src/include/assert.h
M src/include/program_loading.h
6 files changed, 136 insertions(+), 1 deletion(-)

git pull ssh://review.coreboot.org:29418/coreboot refs/changes/18/30118/31