1 files changed, 99 insertions, 26 deletions
diff --git a/sw/z80/crt0.s b/sw/z80/crt0.s
index d0ae3ca..00c7da1 100644
--- a/sw/z80/crt0.s
+++ b/sw/z80/crt0.s
@@ -1,30 +1,103 @@
-    .area _HEADER (ABS)
-    ;; reset vector
-    .org 0
-    jp init
-    
-    .org 0x08
-    reti
-    .org 0x10
-    reti
-    .org 0x18
-    reti
-    .org 0x20
-    reti
-    .org 0x28
-    reti
-    .org 0x30
-    reti
-    .org 0x38
-    reti
-
-    .org 0x100
+;--------------------------------------------------------------------------
+;  crt0.s - Generic crt0.s for a Z80
+;
+;  Copyright (C) 2000, Michael Hope
+;
+;  This library is free software; you can redistribute it and/or modify it
+;  under the terms of the GNU General Public License as published by the
+;  Free Software Foundation; either version 2, or (at your option) any
+;  later version.
+;
+;  This library is distributed in the hope that it will be useful,
+;  but WITHOUT ANY WARRANTY; without even the implied warranty of
+;  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+;  GNU General Public License for more details.
+;
+;  You should have received a copy of the GNU General Public License 
+;  along with this library; see the file COPYING. If not, write to the
+;  Free Software Foundation, 51 Franklin Street, Fifth Floor, Boston,
+;   MA 02110-1301, USA.
+;
+;  As a special exception, if you link this library with other files,
+;  some of which are compiled with SDCC, to produce an executable,
+;  this library does not by itself cause the resulting executable to
+;  be covered by the GNU General Public License. This exception does
+;  not however invalidate any other reasons why the executable file
+;   might be covered by the GNU General Public License.
+;--------------------------------------------------------------------------
 
+	.module crt0
+	.globl	_kmain
+
+	.area	_HEADER (ABS)
+	;; Reset vector
+	.org 	0
+	jp	init
+
+	.org	0x08
+	reti
+	.org	0x10
+	reti
+	.org	0x18
+	reti
+	.org	0x20
+	reti
+	.org	0x28
+	reti
+	.org	0x30
+	reti
+	.org	0x38
+	reti
+
+	.org	0x100
 init:
-    ;; set stack
-    ld sp,#0xFFFF
+	;; Set stack pointer directly above top of memory.
+	ld	sp,#0xFFFF
+
+	;; Initialise global variables
+	call	gsinit
+	call	_kmain
+	jp	    _exit
+
+	;; Ordering of segments for the linker.
+	.area	_HOME
+	.area	_CODE
+	.area	_INITIALIZER
+	.area   _GSINIT
+	.area   _GSFINAL
+
+	.area	_DATA
+	.area	_INITIALIZED
+	.area	_BSEG
+	.area   _BSS
+	.area   _HEAP
+
+	.area   _CODE
+
+__clock::
+	ld	a,#2
+	rst	0x08
+	ret
+
+_exit::
+	;; Exit - special code to the emulator
+	ld	a,#0
+	rst	0x08
+1$:
+	halt
+	jr	1$
+
+	.area   _GSINIT
+gsinit::
+	; ld	bc, #l__INITIALIZER
+	ld	a, b
+	or	a, c
+	jr	Z, gsinit_next
+	; ld	de, #s__INITIALIZED
+	; ld	hl, #s__INITIALIZER
+	ldir
+gsinit_next:
 
-    ;; call C main function
-    call _main
+	.area   _GSFINAL
+	ret
 
-.globl _main