lib/i86/rts/_sendrec.s

   1 .define __send, __receive, __sendrec
   2
   3 ! See ../h/com.h for C definitions
   4 SEND = 1
   5 RECEIVE = 2
   6 BOTH = 3
   7 SYSVEC = 32
   8
   9 !*========================================================================*
  10 !                           _send and _receive                            *
  11 !*========================================================================*
  12 ! _send(), _receive(), _sendrec() all save bp, but destroy ax, bx, and cx.
  13 .extern __send, __receive, __sendrec
  14 __send: mov cx,*SEND            ! _send(dest, ptr)
  15         jmp L0
  16
  17 __receive:
  18         mov cx,*RECEIVE         ! _receive(src, ptr)
  19         jmp L0
  20
  21 __sendrec:
  22         mov cx,*BOTH            ! _sendrec(srcdest, ptr)
  23         jmp L0
  24
  25   L0:   push bp                 ! save bp
  26         mov bp,sp               ! can't index off sp
  27         mov ax,4(bp)            ! ax = dest-src
  28         mov bx,6(bp)            ! bx = message pointer
  29         int SYSVEC              ! trap to the kernel
  30         pop bp                  ! restore bp
  31         ret                     ! return
  32