1/*
2
3Copyright (c) 2005 Red Hat Incorporated.
4All rights reserved.
5
6Redistribution and use in source and binary forms, with or without
7modification, are permitted provided that the following conditions are met:
8
9    Redistributions of source code must retain the above copyright
10    notice, this list of conditions and the following disclaimer.
11
12    Redistributions in binary form must reproduce the above copyright
13    notice, this list of conditions and the following disclaimer in the
14    documentation and/or other materials provided with the distribution.
15
16    The name of Red Hat Incorporated may not be used to endorse
17    or promote products derived from this software without specific
18    prior written permission.
19
20THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
21AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
22IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
23DISCLAIMED.  IN NO EVENT SHALL RED HAT INCORPORATED BE LIABLE FOR ANY
24DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
25(INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
26LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
27ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
28(INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
29SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
30
31*/
32
33#if defined(__r8c_cpu__) || defined(__m16c_cpu__)
34#define A16 1
35#endif
36
37/* We implement setjmp/longjmp much like the way gcc implements
38   exceptions - we create new stack frames, then switch to them and
39   return.  Thus, the two setjmp's below each push all the relevent
40   registers, then copy the whole frame into the buffer (first $sp is
41   moved, then smovf copies the frame itself), and the two longjmps
42   restore $sp, copy the frame back into place, and issue the same
43   return as the setjmp would have used.
44
45   Since the sizes of registers differs between the 16 and 24 bit
46   models, we provide separate implementations for each rather than
47   trying to parameterize them.
48
49   Jump buffer sizes: 21 bytes for 16 bit, 34 bytes for 24 bit.
50*/
51
52	.text
53
54#ifdef A16	/* 16 bit versions */
55
56	.global	_setjmp
57_setjmp:
58	enter	#0
59	pushm	r1,r2,r3,a0,a1,sb,fb
60
61; At this point, the stack looks like this:
62; ... [pc:3] [oldfb:2] <fb> [r1:2] [r2:2] [r3:2] [a0:2] [a1:2] [sb:2] [fb:2] <sp> */
63
64	mov.w	r1,a1		;  a1 is the destination of smovf
65	mov.b	#0,r1h
66	stc	sp,a0		;  r1h:a0 is the source of smovf
67	mov.w	a0,[a1]
68	add.w	#2,a1
69	mov.w	#19,r3		;  plus two for sp later
70	smovf.b
71
72	; Return 0 to caller.
73	mov.w	#0,r0
74	popm	r1,r2,r3,a0,a1,sb,fb
75	exitd
76
77	.global	_longjmp
78_longjmp:
79	enter	#0
80	mov.w	r1,a0		;  pointer to jump buf
81	mov.w	r2,r0		;  setjmp's "new" return value
82
83	mov.b	#0,r1h		;  r1h:	a0 is the source, now jmpbuf
84	mov.w	[a0],a1		;  dest is new stack
85	ldc	a1,sp
86	add.w	#2,a0
87	mov.w	#19,r3
88	smovf.b
89
90	;; now return to our caller with this newly restored frame
91	popm	r1,r2,r3,a0,a1,sb,fb
92	exitd
93
94#else	/* 24 bit versions */
95
96	.global	_setjmp
97_setjmp:
98	enter	#0
99	pushm	r1,r2,r3,a0,a1,sb,fb
100
101; At this point, the stack looks like this:
102; ... [jbuf:4] [pc:4] [oldfb:4] <fb> [r1:2] [r2:2] [r3:2] [a0:4] [a1:4] [sb:4] [fb:4] <sp> */
103
104	mov.l	8[fb],a1	;  a1 is the destination of smovf
105	stc	sp,a0		;  r1h:a0 is the source of smovf
106	mov.l	a0,[a1]
107	add.l	#4,a1
108	mov.w	#30,r3		;  plus two for sp later
109	smovf.b
110
111	; Return 0 to caller.
112	mov.w	#0,r0
113	popm	r1,r2,r3,a0,a1,sb,fb
114	exitd
115
116	.global	_longjmp
117_longjmp:
118	enter	#0
119; ... [rv:2] [jbuf:4] [pc:4] [oldfb:4] <fb>
120	mov.l	8[fb],a0	;  pointer to jump buf
121	mov.w	12[fb],r0	;  setjmp's "new" return value
122
123	mov.l	[a0],a1		;  dest is new stack
124	ldc	a1,sp
125	add.l	#4,a0
126	mov.w	#30,r3
127	smovf.b
128
129	;; now return to our caller with this newly restored frame
130	popm	r1,r2,r3,a0,a1,sb,fb
131	exitd
132#endif
133
134