1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
|
;--------------------------------------------------------------------------
; 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 _main
.area _HEADER (ABS)
;; Reset vector
.org 0
jp init
.org 0x08
ei
reti
ei
.org 0x10
ei
reti
.org 0x18
ei
reti
.org 0x20
ei
reti
.org 0x28
ei
reti
.org 0x30
ei
reti
.org 0x38
ei
reti
.org 0x100
init:
;; Set stack pointer directly above top of memory.
ld sp,#0x0000
;; Initialise global variables
call gsinit
call _main
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:
.area _GSFINAL
ret
|
