src/arch/x86/include/smm.h

   1 /* SPDX-License-Identifier: GPL-2.0-only */
   2
   3 #include <stddef.h>
   4 #include <stdint.h>
   5 #include <cpu/x86/smm.h>
   6
   7 /*
   8  * calls into SMM with the given cmd and subcmd in eax, and arg in ebx
   9  *
  10  * static inline because the resulting assembly is often smaller than
  11  * the call sequence due to constant folding.
  12  */
  13 static inline u32 call_smm(u8 cmd, u8 subcmd, void *arg)
  14 {
  15         u32 res = 0;
  16         __asm__ __volatile__ (
  17                 "outb %b0, %3"
  18                 : "=a" (res)
  19                 : "a" ((subcmd << 8) | cmd), "b" (arg), "i" (APM_CNT));
  20         return res;
  21 }