xref: /openbsd/sys/arch/arm64/include/setjmp.h (revision 76d0caae)
1 /*	$OpenBSD: setjmp.h,v 1.1 2016/12/17 23:38:33 patrick Exp $	*/
2 /*	$NetBSD: setjmp.h,v 1.2 2001/08/25 14:45:59 bjh21 Exp $	*/
3 
4 /*
5  * machine/setjmp.h: machine dependent setjmp-related information.
6  */
7 
8 #define	_JBLEN	64		/* size, in longs, of a jmp_buf */
9 
10 /*
11  * NOTE: The internal structure of a jmp_buf is *PRIVATE*
12  *       This information is provided as there is software
13  *       that fiddles with this with obtain the stack pointer
14  *	 (yes really ! and it's commercial !).
15  *
16  * Description of the setjmp buffer
17  *
18  * word  0	magic number	(dependant on creator)
19  *       1 -  3	f4		fp register 4
20  *	 4 -  6	f5		fp register 5
21  *	 7 -  9 f6		fp register 6
22  *	10 - 12	f7		fp register 7
23  *	13	fpsr		fp status register
24  *	14	r4		register 4
25  *	15	r5		register 5
26  *	16	r6		register 6
27  *	17	r7		register 7
28  *	18	r8		register 8
29  *	19	r9		register 9
30  *	20	r10		register 10 (sl)
31  *	21	r11		register 11 (fp)
32  *	22	r12		register 12 (ip)
33  *	23	r13		register 13 (sp)
34  *	24	r14		register 14 (lr)
35  *	25	signal mask	(dependant on magic)
36  *	26	(con't)
37  *	27	(con't)
38  *	28	(con't)
39  *
40  * The magic number number identifies the jmp_buf and
41  * how the buffer was created as well as providing
42  * a sanity check.
43  *
44  * A side note I should mention - please do not tamper
45  * with the floating point fields. While they are
46  * always saved and restored at the moment this cannot
47  * be guaranteed especially if the compiler happens
48  * to be generating soft-float code so no fp
49  * registers will be used.
50  *
51  * Whilst this can be seen an encouraging people to
52  * use the setjmp buffer in this way I think that it
53  * is for the best then if changes occur compiles will
54  * break rather than just having new builds falling over
55  * mysteriously.
56  */
57 
58 #define _JB_MAGIC__SETJMP	0x4278f500
59 #define _JB_MAGIC_SETJMP	0x4278f501
60 
61 /* Valid for all jmp_buf's */
62 
63 #define _JB_MAGIC		 0
64 #define _JB_REG_F4		 1
65 #define _JB_REG_F5		 4
66 #define _JB_REG_F6		 7
67 #define _JB_REG_F7		10
68 #define _JB_REG_FPSR		13
69 #define _JB_REG_R4		14
70 #define _JB_REG_R5		15
71 #define _JB_REG_R6		16
72 #define _JB_REG_R7		17
73 #define _JB_REG_R8		18
74 #define _JB_REG_R9		19
75 #define _JB_REG_R10		20
76 #define _JB_REG_R11		21
77 #define _JB_REG_R12		22
78 #define _JB_REG_R13		23
79 #define _JB_REG_R14		24
80 
81 /* Only valid with the _JB_MAGIC_SETJMP magic */
82 
83 #define _JB_SIGMASK		25
84