arch/x86_64-pc/exec/userstate.s

   1 #include <aros/x86_64/asm.h>
   2
   3         .text
   4         .align  16
   5
   6         .globl  cpu_SuperState
   7         .type   cpu_SuperState, @function
   8
   9         // This is a SuperState() helper. It's called via Supervisor().
  10         // Its job is to restore a stack pointer and return to user's code.
  11 cpu_SuperState:
  12         movq    %rsp, %rax              // return int handler stack
  13         movq    24(%rax),%rsp           // use user stack
  14         pushq   (%rax)                  // push return address
  15 cpu_UserState:
  16         ret                             // return from SuperState() call
  17
  18         .size  cpu_SuperState, .-cpu_SuperState
  19
  20         .globl  AROS_SLIB_ENTRY(UserState, Exec, 26)
  21         .type   AROS_SLIB_ENTRY(UserState, Exec, 26), @function
  22
  23 AROS_SLIB_ENTRY(UserState, Exec, 26):
  24         // Supervisor return stack is already in rdi
  25         movq    %rsp, 24(%rdi)                  // put USP onto exception stack frame
  26         movq    %rdi, %rsp                      // SSP = SP
  27         leaq    cpu_UserState(%rip), %rax
  28         movq    %rax, (%rsp)                    // return at this address
  29         iretq
  30
  31         .size  AROS_SLIB_ENTRY(UserState, Exec, 26), .-AROS_SLIB_ENTRY(UserState, Exec, 26)