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#include <picolibc.h>
34
35#if defined(__r8c_cpu__) || defined(__m16c_cpu__)
36#define A16 1
37#endif
38
39/* We implement setjmp/longjmp much like the way gcc implements
40   exceptions - we create new stack frames, then switch to them and
41   return.  Thus, the two setjmp's below each push all the relevent
42   registers, then copy the whole frame into the buffer (first $sp is
43   moved, then smovf copies the frame itself), and the two longjmps
44   restore $sp, copy the frame back into place, and issue the same
45   return as the setjmp would have used.
46
47   Since the sizes of registers differs between the 16 and 24 bit
48   models, we provide separate implementations for each rather than
49   trying to parameterize them.
50
51   Jump buffer sizes: 21 bytes for 16 bit, 34 bytes for 24 bit.
52*/
53
54	.text
55
56#ifdef A16	/* 16 bit versions */
57
58	.global	_setjmp
59_setjmp:
60	enter	#0
61	pushm	r1,r2,r3,a0,a1,sb,fb
62
63; At this point, the stack looks like this:
64; ... [pc:3] [oldfb:2] <fb> [r1:2] [r2:2] [r3:2] [a0:2] [a1:2] [sb:2] [fb:2] <sp> */
65
66	mov.w	r1,a1		;  a1 is the destination of smovf
67	mov.b	#0,r1h
68	stc	sp,a0		;  r1h:a0 is the source of smovf
69	mov.w	a0,[a1]
70	add.w	#2,a1
71	mov.w	#19,r3		;  plus two for sp later
72	smovf.b
73
74	; Return 0 to caller.
75	mov.w	#0,r0
76	popm	r1,r2,r3,a0,a1,sb,fb
77	exitd
78
79	.global	_longjmp
80_longjmp:
81	enter	#0
82	mov.w	r1,a0		;  pointer to jump buf
83	mov.w	r2,r0		;  setjmp's "new" return value
84
85	mov.b	#0,r1h		;  r1h:	a0 is the source, now jmpbuf
86	mov.w	[a0],a1		;  dest is new stack
87	ldc	a1,sp
88	add.w	#2,a0
89	mov.w	#19,r3
90	smovf.b
91
92	;; now return to our caller with this newly restored frame
93	popm	r1,r2,r3,a0,a1,sb,fb
94	exitd
95
96#else	/* 24 bit versions */
97
98	.global	_setjmp
99_setjmp:
100	enter	#0
101	pushm	r1,r2,r3,a0,a1,sb,fb
102
103; At this point, the stack looks like this:
104; ... [jbuf:4] [pc:4] [oldfb:4] <fb> [r1:2] [r2:2] [r3:2] [a0:4] [a1:4] [sb:4] [fb:4] <sp> */
105
106	mov.l	8[fb],a1	;  a1 is the destination of smovf
107	stc	sp,a0		;  r1h:a0 is the source of smovf
108	mov.l	a0,[a1]
109	add.l	#4,a1
110	mov.w	#30,r3		;  plus two for sp later
111	smovf.b
112
113	; Return 0 to caller.
114	mov.w	#0,r0
115	popm	r1,r2,r3,a0,a1,sb,fb
116	exitd
117
118	.global	_longjmp
119_longjmp:
120	enter	#0
121; ... [rv:2] [jbuf:4] [pc:4] [oldfb:4] <fb>
122	mov.l	8[fb],a0	;  pointer to jump buf
123	mov.w	12[fb],r0	;  setjmp's "new" return value
124
125	mov.l	[a0],a1		;  dest is new stack
126	ldc	a1,sp
127	add.l	#4,a0
128	mov.w	#30,r3
129	smovf.b
130
131	;; now return to our caller with this newly restored frame
132	popm	r1,r2,r3,a0,a1,sb,fb
133	exitd
134#endif
135
136