Added support for gsinit packing.

[fw/sdcc] / device / lib / z80 / crt0.s

diff --git a/device/lib/z80/crt0.s b/device/lib/z80/crt0.s
index 9d51c51aaee1a57d95faae08b054b217548f66e4..23843568f76eec4bf474141185bc912f3c3102cf 100644 (file)
--- a/device/lib/z80/crt0.s
+++ b/device/lib/z80/crt0.s
@@ -1,5 +1,5 @@
        ;; Generic crt0.s for a Z80
-       .globl  __main
+       .globl  _main
 
        .area _HEADER (ABS)
        ;; Reset vector
@@ -21,29 +21,101 @@
        .org    0x38
        reti
        
-       .org    0x150
+       .org    0x100
 init:
        ;; Stack at the top of memory.
        ld      sp,#0xffff        
 
-       ;; Use _main instead of main to bypass sdcc's intelligence
-       call    __main
+        ;; Initialise global variables
+        call    gsinit
+       call    _main
        jp      _exit
 
        ;; Ordering of segments for the linker.
        .area   _CODE
+        .area   _GSINIT
+        .area   _GSFINAL
+        
        .area   _DATA
+        .area   _BSS
 
-       .area   _CODE
+        .area   _CODE
+__clock::
+       ld      a,#2
+        rst     0x08
+       ret
+       
 _getsp::
        ld      hl,#0
        add     hl,sp
        ret
-       
+
+__printTStates::       
+       ld      a,#3
+       out     (0xff),a
+       ret
+
 _exit::
        ;; Exit - special code to the emulator
        ld      a,#0
-       out     (1),a
+        rst     0x08
 1$:
        halt
        jr      1$
+
+        ;; Special RLE decoder used for initing global data
+__initrleblock::
+        ;; Pop the return address
+        pop     hl
+        ;; Save registers
+        push    bc
+        push    de
+
+        ;; Pull the destination address out
+        ld      c,(hl)
+        inc     hl
+        ld      b,(hl)
+        inc     hl
+1$:
+        ;; Fetch the run
+        ld      e,(hl)
+        inc     hl
+        ;; Negative means a run
+        bit     7,e
+        jp      z,2$
+        ;; Code for expanding a run
+        ld      a,(hl)
+        inc     hl
+3$:
+        ld      (bc),a
+        inc     bc
+        inc     e
+        jp      nz,3$
+        jp      1$
+2$:
+        ;; Zero means end of a block
+        xor     a
+        or      e
+        jp      z,4$
+        ;; Code for expanding a block
+5$:     
+        ld      a,(hl)        
+        inc     hl
+        ld      (bc),a
+        inc     bc
+        dec     e
+        jp      nz,5$
+        jp      1$
+4$:     
+        pop     de
+        pop     bc
+
+        ;; Push the return address back onto the stack
+        push    hl
+        ret
+
+        .area   _GSINIT
+gsinit::       
+
+        .area   _GSFINAL
+        ret