diff options
Diffstat (limited to 'src/cpu/x86')
| -rw-r--r-- | src/cpu/x86/smm/smm_stub.S | 43 |
1 files changed, 5 insertions, 38 deletions
diff --git a/src/cpu/x86/smm/smm_stub.S b/src/cpu/x86/smm/smm_stub.S index 673ab2c50c..f97ab59cd9 100644 --- a/src/cpu/x86/smm/smm_stub.S +++ b/src/cpu/x86/smm/smm_stub.S @@ -183,37 +183,22 @@ apicid_end: movl $0, 4(%ebx) #endif - /* Create stack frame by pushing a NULL stack base pointer */ - pushl $0x0 - mov %esp, %ebp - - /* Allocate locals (efer_backup) */ - subl $0x8, %esp - align_stack: /* Align stack to 16 bytes. Another 32 bytes are pushed below. */ andl $0xfffffff0, %esp + /* Call into the c-based SMM relocation function with the platform + * parameters. Equivalent to: + * struct arg = { cpu_num, canary }; + * c_handler(&arg) + */ #if ENV_X86_64 mov %ecx, %edi - /* Backup IA32_EFER. Preserves ebx. */ - movl $(IA32_EFER), %ecx - rdmsr - movl %eax, -0x4(%ebp) - movl %edx, -0x8(%ebp) - /* entry64.inc preserves ebx, esi, edi, ebp */ #include <cpu/x86/64bit/entry64.inc> mov %edi, %ecx -#endif - /* Call into the c-based SMM relocation function with the platform - * parameters. Equivalent to: - * struct arg = { cpu_num, canary }; - * c_handler(&arg) - */ -#if ENV_X86_64 push %rbx /* uintptr_t *canary */ push %rcx /* size_t cpu */ @@ -221,24 +206,6 @@ align_stack: movabs c_handler, %eax call *%rax - - /* - * The only reason to go back to protected mode is that RSM doesn't restore - * MSR registers and MSR IA32_EFER was modified by entering long mode. - * Drop to protected mode to safely operate on the IA32_EFER MSR. - */ - - /* Disable long mode. */ - #include <cpu/x86/64bit/exit32.inc> - - /* Restore IA32_EFER as RSM doesn't restore MSRs. */ - movl $(IA32_EFER), %ecx - rdmsr - movl -0x4(%ebp), %eax - movl -0x8(%ebp), %edx - - wrmsr - #else push $0x0 /* Padding */ push %ebx /* uintptr_t *canary */ |