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author | Eugene Myers <edmyers@tycho.nsa.gov> | 2020-01-21 17:01:47 -0500 |
---|---|---|
committer | Patrick Georgi <pgeorgi@google.com> | 2020-02-05 18:49:27 +0000 |
commit | ae438be57856e994774ec0e2521d49f1ad09bd6f (patch) | |
tree | b174c6b496de3524bca2dd027c686fa5c9b5bd8b /src/cpu/x86/smm/smm_stub.S | |
parent | d498e52c3f024971f342da9029fd7f11668c0a3d (diff) | |
download | coreboot-ae438be57856e994774ec0e2521d49f1ad09bd6f.tar.xz |
security/intel/stm: Add STM support
This update is a combination of all four of the patches so that the
commit can be done without breaking parts of coreboot. This possible
breakage is because of the cross-dependencies between the original
separate patches would cause failure because of data structure changes.
security/intel/stm
This directory contains the functions that check and move the STM to the
MSEG, create its page tables, and create the BIOS resource list.
The STM page tables is a six page region located in the MSEG and are
pointed to by the CR3 Offset field in the MSEG header. The initial
page tables will identity map all memory between 0-4G. The STM starts
in IA32e mode, which requires page tables to exist at startup.
The BIOS resource list defines the resources that the SMI Handler is
allowed to access. This includes the SMM memory area where the SMI
handler resides and other resources such as I/O devices. The STM uses
the BIOS resource list to restrict the SMI handler's accesses.
The BIOS resource list is currently located in the same area as the
SMI handler. This location is shown in the comment section before
smm_load_module in smm_module_loader.c
Note: The files within security/intel/stm come directly from their
Tianocore counterparts. Unnecessary code has been removed and the
remaining code has been converted to meet coreboot coding requirements.
For more information see:
SMI Transfer Monitor (STM) User Guide, Intel Corp.,
August 2015, Rev 1.0, can be found at firmware.intel.com
include/cpu/x86:
Addtions to include/cpu/x86 for STM support.
cpu/x86:
STM Set up - The STM needs to be loaded into the MSEG during BIOS
initialization and the SMM Monitor Control MSR be set to indicate
that an STM is in the system.
cpu/x86/smm:
SMI module loader modifications needed to set up the
SMM descriptors used by the STM during its initialization
Change-Id: If4adcd92c341162630ce1ec357ffcf8a135785ec
Signed-off-by: Eugene D. Myers <edmyers@tycho.nsa.gov>
Reviewed-on: https://review.coreboot.org/c/coreboot/+/33234
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
Reviewed-by: Patrick Georgi <pgeorgi@google.com>
Reviewed-by: ron minnich <rminnich@gmail.com>
Diffstat (limited to 'src/cpu/x86/smm/smm_stub.S')
-rw-r--r-- | src/cpu/x86/smm/smm_stub.S | 13 |
1 files changed, 13 insertions, 0 deletions
diff --git a/src/cpu/x86/smm/smm_stub.S b/src/cpu/x86/smm/smm_stub.S index f0e55f9a18..8207d233a0 100644 --- a/src/cpu/x86/smm/smm_stub.S +++ b/src/cpu/x86/smm/smm_stub.S @@ -44,6 +44,11 @@ smbase: .long 0 save_state_size: .long 0 +num_cpus: +.long 0 +/* allows the STM to bring up SMM in 32-bit mode */ +start32_offset: +.long smm_trampoline32 - _start /* apic_to_cpu_num is a table mapping the default APIC id to CPU num. If the * APIC id is found at the given index, the contiguous CPU number is index * into the table. */ @@ -90,6 +95,14 @@ smm_relocate_gdt: /* gdt selector 0x10, flat data segment */ .word 0xffff, 0x0000 .byte 0x00, 0x93, 0xcf, 0x00 + + /* gdt selector 0x18, flat code segment (64-bit) */ + .word 0xffff, 0x0000 + .byte 0x00, 0x9b, 0xcf, 0x00 + + /* gdt selector 0x20 tss segment */ + .word 0xffff, 0x0000 + .byte 0x00, 0x8b, 0x80, 0x00 smm_relocate_gdt_end: .align 4 |