summaryrefslogtreecommitdiff
path: root/ports/sysdeps/unix/sysv/linux/arm/setcontext.S
blob: d163fc4a4c0ea63edfa8a6c59a092c1ec9c71aca (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
/* Copyright (C) 2012 Free Software Foundation, Inc.
   This file is part of the GNU C Library.

   The GNU C Library is free software; you can redistribute it and/or
   modify it under the terms of the GNU Lesser General Public
   License as published by the Free Software Foundation; either
   version 2.1 of the License, or (at your option) any later version.

   The GNU C Library is distributed in the hope that it will be useful,
   but WITHOUT ANY WARRANTY; without even the implied warranty of
   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
   Lesser General Public License for more details.

   You should have received a copy of the GNU Lesser General Public
   License along with the GNU C Library; if not, see
   <http://www.gnu.org/licenses/>.  */

#include <sysdep.h>
#include <rtld-global-offsets.h>

#include "ucontext_i.h"

	.syntax unified
	.text

/* int setcontext (const ucontext_t *ucp) */

ENTRY(__setcontext)
	mov	r4, r0
	add	r0, r0, #UCONTEXT_REGSPACE

        /* Restore the VFP registers.  Copied from arm/__longjmp.S.  */
#ifdef PIC
        ldr     r2, 1f
        ldr     r1, Lrtld_global_ro
0:      add     r2, pc, r2
        ldr     r2, [r2, r1]
        ldr     r2, [r2, #RTLD_GLOBAL_RO_DL_HWCAP_OFFSET]
#else
        ldr     r2, Lhwcap
        ldr     r2, [r2, #0]
#endif

        tst     r2, #HWCAP_ARM_VFP
        beq     Lno_vfp_sc

        /* Following instruction is vldmia r0!, {d8-d15}.  */
        ldc     p11, cr8, [r0], #64
        /* Restore the floating-point status register.  */
        ldr     r1, [r0], #4
        /* Following instruction is fmxr fpscr, r1.  */
        mcr     p10, 7, r1, cr1, cr0, 0
Lno_vfp_sc:
        tst     r2, #HWCAP_ARM_IWMMXT
        beq     Lno_iwmmxt_sc

        /* Restore the call-preserved iWMMXt registers.  */
        /* Following instructions are wldrd wr10, [r0], #8 (etc.)  */
        ldcl    p1, cr10, [r0], #8
        ldcl    p1, cr11, [r0], #8
        ldcl    p1, cr12, [r0], #8
        ldcl    p1, cr13, [r0], #8
        ldcl    p1, cr14, [r0], #8
        ldcl    p1, cr15, [r0], #8
Lno_iwmmxt_sc:

	/* Now bring back the signal status.  */
	mov	r0, #SIG_SETMASK
	add	r1, r4, #UCONTEXT_SIGMASK
	mov	r2, #0
	bl	PLTJMP(__sigprocmask)

        /* Loading r0-r3 makes makecontext easier.  */
        add     r14, r4, #MCONTEXT_ARM_R0
        ldmia   r14, {r0-r12}
        ldr     r13, [r14, #(MCONTEXT_ARM_SP - MCONTEXT_ARM_R0)]
        add     r14, r14, #(MCONTEXT_ARM_LR - MCONTEXT_ARM_R0)
        ldmia   r14, {r14, pc}

END(setcontext)
weak_alias(__setcontext, setcontext)

	/* Called when a makecontext() context returns.  Start the
	   context in R4 or fall through to exit().  */
ENTRY(__startcontext)
        movs    r0, r4
        bne     PLTJMP(__setcontext)

        @ New context was 0 - exit
        b       PLTJMP(HIDDEN_JUMPTARGET(_exit))
END(__startcontext)

#ifdef PIC
1:      .long   _GLOBAL_OFFSET_TABLE_ - 0b - 8
Lrtld_global_ro:
        .long   C_SYMBOL_NAME(_rtld_global_ro)(GOT)
#else
Lhwcap:
        .long   C_SYMBOL_NAME(_dl_hwcap)
#endif