Re: [POC Seabios PATCH] seabios: use isolated SMM address space for relocation


Boris Ostrovsky <boris.ostrovsky@...>
 

On 8/16/19 7:24 AM, Igor Mammedov wrote:
for purpose of demo SMRAM (at 0x30000) is aliased at a0000 in system address space
for easy initialization of SMI entry point.
Here is resulting debug output showing that RAM at 0x30000 is not affected
by SMM and only RAM in SMM adderss space is modified:

init smm
smm_relocate: before relocaten
smm_relocate: RAM codeentry 0
smm_relocate: RAM cpu.i64.smm_base 0
smm_relocate: SMRAM codeentry f000c831eac88c
smm_relocate: SMRAM cpu.i64.smm_base 0
handle_smi cmd=0 smbase=0x00030000
smm_relocate: after relocaten
smm_relocate: RAM codeentry 0
smm_relocate: RAM cpu.i64.smm_base 0
smm_relocate: SMRAM codeentry f000c831eac88c
smm_relocate: SMRAM cpu.i64.smm_base a0000

I most likely don't understand how this is supposed to work but aren't
we here successfully reading SMRAM from non-SMM context, something we
are not supposed to be able to do?


-boris

Join rfc@edk2.groups.io to automatically receive all group messages.