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   1         ;; Generic crt0.s for a GBZ80
   2         .globl  _main
   3
   4         .area   _HEADER (ABS)
   5         ;; Reset vector
   6         .org    0
   7         jp      init
   8
   9         .org    0x08
  10         reti
  11         .org    0x10
  12         reti
  13         .org    0x18
  14         reti
  15         .org    0x20
  16         reti
  17         .org    0x28
  18         reti
  19         .org    0x30
  20         reti
  21         .org    0x38
  22         reti
  23
  24         .org    0x100
  25         jp      0x150
  26
  27         .org    0x150
  28 init:
  29         di
  30         ;; Stack at the top of memory.
  31         ld      sp,#0xdfff
  32
  33         ;; Setup global data
  34         call    gsinit
  35
  36         ;; Use _main instead of main to bypass sdcc's intelligence
  37         call    _main
  38         jp      _exit
  39
  40         ;; Ordering of segments for the linker.
  41         .area   _HOME
  42         .area   _CODE
  43         .area   _GSINIT
  44         .area   _GSFINAL
  45
  46         .area   _DATA
  47         .area   _BSS
  48         .area   _HEAP
  49
  50         .area   _CODE
  51 __clock::
  52         ld      a,#2
  53         rst     0x08
  54         ret
  55
  56 _exit::
  57         ;; Exit - special code to the emulator
  58         ld      a,#0
  59         rst     0x08
  60 1$:
  61         halt
  62         jr      1$
  63
  64         .area   _GSINIT
  65 gsinit::
  66
  67         .area   _GSFINAL
  68         ret