diff options
| -rw-r--r-- | src/arch/x86/include/smm_call.h | 5 |
1 files changed, 4 insertions, 1 deletions
diff --git a/src/arch/x86/include/smm_call.h b/src/arch/x86/include/smm_call.h index 66925c4a06..dc780399e0 100644 --- a/src/arch/x86/include/smm_call.h +++ b/src/arch/x86/include/smm_call.h @@ -4,7 +4,10 @@ #include <cpu/x86/smm.h> /* - * calls into SMM with the given cmd and subcmd in eax, and arg in ebx + * Call the APMC SMI handler that resides in SMM. First, the command and sub-command are stored + * in eax, and the argument pointer is stored in ebx, then the command byte is written to the + * APMC IO port to trigger the SMI. The APMC SMI handler then reads the command from the APMC + * IO port and the contents of eax and ebx from the SMM state save area. * * static inline because the resulting assembly is often smaller than * the call sequence due to constant folding. |