gbdk-2020 | GameBoy Development Kit |
| download: https://git.y1.nz/archives/gbdk.tar.gz | |
| README | Files | Log | Refs | LICENSE |
gbdk-lib/libc/asm/sm83/setjmp.s
1 ;--------------------------------------------------------------------------
2 ; setjmp.s
3 ;
4 ; Copyright (C) 2011-2014, Philipp Klaus Krause
5 ;
6 ; This library is free software; you can redistribute it and/or modify it
7 ; under the terms of the GNU General Public License as published by the
8 ; Free Software Foundation; either version 2, or (at your option) any
9 ; later version.
10 ;
11 ; This library is distributed in the hope that it will be useful,
12 ; but WITHOUT ANY WARRANTY; without even the implied warranty of
13 ; MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
14 ; GNU General Public License for more details.
15 ;
16 ; You should have received a copy of the GNU General Public License
17 ; along with this library; see the file COPYING. If not, write to the
18 ; Free Software Foundation, 51 Franklin Street, Fifth Floor, Boston,
19 ; MA 02110-1301, USA.
20 ;
21 ; As a special exception, if you link this library with other files,
22 ; some of which are compiled with SDCC, to produce an executable,
23 ; this library does not by itself cause the resulting executable to
24 ; be covered by the GNU General Public License. This exception does
25 ; not however invalidate any other reasons why the executable file
26 ; might be covered by the GNU General Public License.
27 ;--------------------------------------------------------------------------
28
29 .module longjmp
30
31 .area _HOME
32
33 .globl ___setjmp
34
35 ___setjmp:
36 pop bc
37 pop de
38 push de
39 push bc
40
41 ; Store stack pointer.
42 ldhl sp, #0
43 push de
44 push hl
45 pop de
46 pop hl
47 ld (hl), e
48 inc hl
49 ld (hl), d
50 inc hl
51
52 ; Store return address.
53 ld (hl), c
54 inc hl
55 ld (hl), b
56
57 ; Return 0.
58 xor a, a
59 ld e, a
60 ld d, a
61 ret
62
63 .globl _longjmp
64
65 _longjmp:
66 pop af
67 pop hl
68 pop de
69
70 ; Ensure that return value is non-zero.
71 ld a, e
72 or a, d
73 jr NZ, 0001$
74 inc de
75 0001$:
76
77 ; Get stack pointer.
78 ld c, (hl)
79 inc hl
80 ld b, (hl)
81 inc hl
82
83 ; Adjust stack pointer.
84 push hl
85 push bc
86 pop hl
87 pop bc
88 ld sp, hl
89 push bc
90 pop hl
91
92 ; Get return address.
93 ld c, (hl)
94 inc hl
95 ld b, (hl)
96
97 ; Set return address.
98 pop af
99 push bc
100
101 ; Return value is in de.
102
103 ; Jump.
104 ret
105
This webpage is intended to be an accessible preview of this repository. To get a fuller picture, clone it and use the git CLI.