diff options
Diffstat (limited to 'src/cpu/x86/smm/smm_stub.S')
| -rw-r--r-- | src/cpu/x86/smm/smm_stub.S | 43 |
1 files changed, 43 insertions, 0 deletions
diff --git a/src/cpu/x86/smm/smm_stub.S b/src/cpu/x86/smm/smm_stub.S index e1f6e5f9f2..824a26b858 100644 --- a/src/cpu/x86/smm/smm_stub.S +++ b/src/cpu/x86/smm/smm_stub.S @@ -36,6 +36,10 @@ c_handler: .long 0 c_handler_arg: .long 0 +fxsave_area: +.long 0 +fxsave_area_size: +.long 0 /* struct smm_runtime begins here. */ smm_runtime: smbase: @@ -122,6 +126,8 @@ smm_trampoline32: * not be assigned. Use the fallback stack and check this condition in * C handler. */ movl $(fallback_stack_top), %esp + /* Clear fxsave location as there will be no saving/restoring. */ + xor %edi, %edi jmp 2f 1: movl stack_size, %eax @@ -130,7 +136,33 @@ smm_trampoline32: subl %eax, %edx mov %edx, %esp + /* calculate fxsave location */ + mov fxsave_area, %edi + test %edi, %edi + jz 2f + movl fxsave_area_size, %eax + mul %ecx + add %eax, %edi + 2: + /* Save location of fxsave area. */ + push %edi + mov %esp, %ebp + test %edi, %edi + jz 1f + + /* Enable sse instructions. */ + mov %cr4, %eax + orl $(CR4_OSFXSR | CR4_OSXMMEXCPT), %eax + mov %eax, %cr4 + + /* Save FP state. */ + fxsave (%edi) + +1: + /* Align stack to 16 bytes. Another 16 bytes are pushed below. */ + andl $0xfffffff0, %esp + /* Call into the c-based SMM relocation function with the platform * parameters. Equivalent to: * struct arg = { c_handler_params, cpu_num, smm_runtime {; @@ -143,5 +175,16 @@ smm_trampoline32: mov c_handler, %eax call *%eax + /* Restore stack from call frame */ + mov %ebp, %esp + /* Retrieve fxsave location. */ + pop %edi + test %edi, %edi + jz 1f + + /* Restore FP state. */ + fxrstor (%edi) + +1: /* Exit from SM mode. */ rsm |