2.9BSD - /usr/src/sys/stand/srt0.s

   1: / Startup code for standalone utilities
   2: / wfj- mod's to allow non sep i/d machines, error recovery
   3: /      note that the bootstrap passes the cputype through in
   4: /      r0.
   5: 
   6: / non-UNIX instructions
   7: mfpi    = 6500^tst
   8: stst    = 170300^tst
   9: mtpi    = 6600^tst
  10: mfpd    = 106500^tst
  11: mtpd    = 106600^tst
  12: spl     = 230
  13: ldfps   = 170100^tst
  14: stfps   = 170200^tst
  15: wait    = 1
  16: rtt     = 6
  17: reset   = 5
  18: / trap	= 104400
  19: 
  20: PS      = 177776
  21: 
  22: .globl  _end
  23: .globl  _main, __rtt
  24: .globl  _edata
  25:         jmp     start
  26: 
  27: /
  28: / trap vectors
  29: /
  30:         trap;340        / bus error
  31:         trap;341        / illegal instruction
  32:         trap;342        / BPT
  33:         trap;343        / IOT
  34:         trap;344        / POWER FAIL
  35:         trap;345        / EMT
  36: tvec:
  37:         start;346       / TRAP
  38: .=400^.
  39: .text
  40: 
  41: 
  42: start:
  43:         mov     $340,*$PS
  44:         mov     $trap,tvec
  45: /
  46: / restore what kind of cpu we are running on
  47:         mov     r0,*$_cputype   / assume that the boot left this in r0
  48: / check if there is a switch register
  49:         mov     $1f,nofault
  50:         tst     CSW
  51:         incb    _haveCSW
  52: 1:
  53:         clr     nofault
  54:         mov     $157776,sp
  55:         mov     $_edata,r0
  56:         mov     $_end,r1
  57:         sub     r0,r1
  58:         inc     r1
  59:         clc
  60:         ror     r1
  61: 1:
  62:         clr     (r0)+
  63:         sob     r1,1b
  64:         jsr     pc,_main
  65: 
  66: / fix up stack to point at trap ps-pc pair,
  67: / located at bottom of memory.
  68: / so we can return to the bootstrap
  69: 
  70: __rtt:
  71:         mov     $140000,sp
  72:         rtt                             / we hope!
  73:         br      .
  74: 
  75: 
  76: .globl  _trap
  77: trap:
  78:         mov     *$PS,-(sp)
  79:         mov     r0,-(sp)
  80:         mov     r1,-(sp)
  81:         tst     nofault
  82:         bne     3f
  83: 2:      jsr     pc,_trap
  84:         mov     (sp)+,r1
  85:         mov     (sp)+,r0
  86:         tst     (sp)+
  87:         rtt
  88: 3:      mov     (sp)+,r1
  89:         mov     (sp)+,r0
  90:         tst     (sp)+
  91:         mov     nofault,(sp)
  92:         rtt
  93: 
  94: .data
  95: .globl  _cputype, _haveCSW
  96: 
  97: nofault:        .=.+2   / where to go on predicted trap
  98: _cputype:       .=.+2   / cpu type (currently 24,40,45 or 70)
  99: _haveCSW:       .=.+1   / one if there is a switch register
 100: KISA6 = 172354
 101: KISA7 = 172356
 102: KDSA6 = 172374
 103: UBMAP = 170200
 104: CSW   = 177570

Defined functions

Defined variables