gbdk-2020 | GameBoy Development Kit |
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gbdk-lib/libc/asm/z80/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 .area _CODE
30
31 .globl ___setjmp
32
33 ___setjmp:
34 pop hl
35 pop iy
36 push af
37 push hl
38
39 ; Store return address.
40 ld 0(iy), l
41 ld 1(iy), h
42
43 ; Store stack pointer.
44 xor a, a
45 ld l, a
46 ld h, a
47 add hl, sp
48 ld 2(iy), l
49 ld 3(iy), h
50
51 ; Store frame pointer.
52 push ix
53 pop hl
54 ld 4(iy), l
55 ld 5(iy), h
56
57 ; Return 0.
58 ld l, a
59 ld h, a
60 ret
61
62 .globl _longjmp
63
64 _longjmp:
65 pop af
66 pop iy
67 pop de
68
69 ; Ensure that return value is non-zero.
70 ld a, e
71 or a, d
72 jr NZ, jump
73 inc de
74 jump:
75
76 ; Restore frame pointer.
77 ld l, 4(iy)
78 ld h, 5(iy)
79 push hl
80 pop ix
81
82 ; Adjust stack pointer.
83 ld l, 2(iy)
84 ld h, 3(iy)
85 ld sp, hl
86 pop hl
87
88 ; Move return value into hl.
89 ex de, hl
90
91 ; Jump.
92 ld c, 0(iy)
93 ld b, 1(iy)
94 push bc
95 ret
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