compilers/linux86-0.16.17/libc/msdos/intr.c

   1
   2 struct REGPACK
   3 {
   4    unsigned r_ax, r_bx, r_cx, r_dx;
   5    unsigned r_bp, r_si, r_di, r_ds, r_es, r_flags;
   6 };
   7
   8 /* DANGER DANGER -- Self modifying code! */
   9
  10 #asm
  11 .text
  12 save_sp:
  13   dw    0
  14 #endasm
  15
  16 intr(intr, regs)
  17 int intr;
  18 struct REGPACK * regs;
  19 {
  20 #asm
  21   mov   bx,sp
  22   push  bp
  23   push  si
  24   push  di
  25   push  es
  26   push  ds
  27
  28   mov   ax,[bx+2]
  29   seg   cs
  30   mov   [intr_inst+1],al
  31   seg   cs
  32   mov   [save_sp],sp
  33
  34   mov   bx,[bx+4]
  35
  36   mov   ah,[bx+18]      ! Flags low byte
  37   sahf
  38
  39   mov   ax,[bx]
  40   push  [bx+2]
  41   mov   cx,[bx+4]
  42   mov   dx,[bx+6]
  43   mov   bp,[bx+8]
  44   mov   si,[bx+10]
  45   mov   di,[bx+12]
  46   mov   es,[bx+16]
  47   mov   ds,[bx+14]
  48   pop   bx
  49
  50 intr_inst:
  51   int   $FF             ! Must be a real int .. consider protected mode.
  52
  53   seg   cs              ! Could be SS as DS==SS
  54   mov   sp,[save_sp]
  55   seg   cs
  56   mov   [save_sp],ds
  57   pop   ds
  58   push  [save_sp]
  59
  60   push  bx
  61   mov   bx,sp
  62   mov   bx,[bx+12]
  63
  64   mov   [bx],ax
  65   pop   [bx+2]
  66   mov   [bx+4],cx
  67   mov   [bx+6],dx
  68   mov   [bx+8],bp
  69   mov   [bx+10],si
  70   mov   [bx+12],di
  71   pop   [bx+14]
  72   mov   [bx+16],es
  73   pushf
  74   pop   [bx+18]
  75
  76   pop   es
  77   pop   di
  78   pop   si
  79   pop   bp
  80
  81 #endasm
  82 }