1/*
2Copyright (c) 2009 Nick Clifton <nickc@redhat.com>
3 */
4#include <picolibc.h>
5
6# setjmp/longjmp for Renesas RX.
7#
8# The jmpbuf looks like this:
9#
10# Register	jmpbuf offset
11# R0		0x0
12# R1		0x4
13# R2		0x8
14# R3		0xc
15# R4		0x10
16# R5		0x14
17# R6		0x18
18# R7		0x1c
19# R8		0x20
20# R9		0x24
21# R10		0x28
22# R11		0x2c
23# R12		0x30
24# R13		0x34
25# R14		0x38
26# R15		0x3c
27# PC		0x40
28#
29# R1 contains the pointer to jmpbuf:
30#
31#	int R1 = setjmp (jmp_buf R1)
32#	void longjmp (jmp_buf R1, int R2)
33#
34# The ABI allows for R1-R5 to be clobbered by functions.  We must be
35# careful to always leave the stack in a usable state in case an
36# interrupt happens.
37
38	.text
39	.global	_setjmp
40	.type	_setjmp, @function
41_setjmp:
42	mov.l	r0, [r1]	; save all the general registers
43	mov.l	r1, 0x4[r1]	; longjmp won't use this, but someone else might.
44	mov.l	r2, 0x8[r1]
45	mov.l	r3, 0xc[r1]
46	mov.l	r4, 0x10[r1]
47	mov.l	r5, 0x14[r1]
48	mov.l	r6, 0x18[r1]
49	mov.l	r7, 0x1c[r1]
50	mov.l	r8, 0x20[r1]
51	mov.l	r9, 0x24[r1]
52	mov.l	r10, 0x28[r1]
53	mov.l	r11, 0x2c[r1]
54	mov.l	r12, 0x30[r1]
55	mov.l	r13, 0x34[r1]
56	mov.l	r14, 0x38[r1]
57	mov.l	r15, 0x3c[r1]
58	mov.l	[r0], r2	; get return address off the stack
59	mov.l	r2, 0x40[r1]	; PC
60	mov	#0, r1		; Return 0.
61	rts
62.Lend1:
63	.size	_setjmp, .Lend1 - _setjmp
64
65
66	.global	_longjmp
67	.type	_longjmp, @function
68_longjmp:
69	tst	r2, r2		; Set the Z flag if r2 is 0.
70	stz	#1, r2		; If the Z flag was set put 1 into the return register.
71	mov	r2, 4[r1]	; Put r2 (our return value) into the setjmp buffer as r1.
72
73	mov.l	[r1], r0	; Restore the stack - there's a slot for PC
74	mov.l	0x40[r1], r2	; Get the saved PC
75	mov.l	r2, [r0]	; Overwrite the old return address
76
77	mov.l	0x3c[r1], r15
78	mov.l	0x38[r1], r14
79	mov.l	0x34[r1], r13
80	mov.l	0x30[r1], r12
81	mov.l	0x2c[r1], r11
82	mov.l	0x28[r1], r10
83	mov.l	0x24[r1], r9
84	mov.l	0x20[r1], r8
85	mov.l	0x1c[r1], r7
86	mov.l	0x18[r1], r6
87	mov.l	0x14[r1], r5
88	mov.l	0x10[r1], r4
89	mov.l	0xc[r1], r3
90	mov.l	0x8[r1], r2
91	mov.l	0x4[r1], r1	; This sets up the new return value
92	rts
93.Lend2:
94	.size	_longjmp, .Lend2 - _longjmp
95