Patrick Rudolph uploaded patch set #13 to this change.

View Change

cpu/x86/smm: Add support for long mode

Enable long mode in SMM handler.
x86_32 isn't affected from this change.

As the rsm instruction used to leave SMM doesn't restore MSR registers,
drop back to protected mode after running the smi_handler and restore
IA32_EFER MSR (which enables long mode support) to previous value.

For now the same page tables as for all other stages are used.
If there's enough space in SMM, one could install additional page tables in
SMRAM to enable additional features.

Tested on Qemu Q35.

Change-Id: I8bba4af4688c723fc079ae905dac95f57ea956f8
Signed-off-by: Patrick Rudolph <siro@das-labor.org>
---
M Documentation/arch/x86/index.md
A src/cpu/x86/64bit/exit32.inc
M src/cpu/x86/smm/smmhandler.S
3 files changed, 140 insertions(+), 1 deletion(-)

git pull ssh://review.coreboot.org:29418/coreboot refs/changes/81/35681/13

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