1/* Copyright (C) 2012-2022 Free Software Foundation, Inc.
2   This file is part of the GNU C Library.
3
4   The GNU C Library is free software; you can redistribute it and/or
5   modify it under the terms of the GNU Lesser General Public
6   License as published by the Free Software Foundation; either
7   version 2.1 of the License, or (at your option) any later version.
8
9   The GNU C Library is distributed in the hope that it will be useful,
10   but WITHOUT ANY WARRANTY; without even the implied warranty of
11   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
12   Lesser General Public License for more details.
13
14   You should have received a copy of the GNU Lesser General Public
15   License along with the GNU C Library; if not, see
16   <https://www.gnu.org/licenses/>.  */
17
18/* ??? Needs more rearrangement for the LDM to handle thumb mode.  */
19#define NO_THUMB
20#include <sysdep.h>
21#include <rtld-global-offsets.h>
22
23#include "ucontext_i.h"
24
25	.syntax unified
26	.text
27
28/* int setcontext (const ucontext_t *ucp) */
29
30ENTRY(__setcontext)
31	mov	r4, r0
32	add	r0, r0, #UCONTEXT_REGSPACE
33
34	/* Restore the VFP registers.  Copied from arm/__longjmp.S.  */
35#ifdef SHARED
36	ldr     r2, 1f
37	ldr     r1, .Lrtld_global_ro
380:      add     r2, pc, r2
39	ldr     r2, [r2, r1]
40	ldr     r2, [r2, #RTLD_GLOBAL_RO_DL_HWCAP_OFFSET]
41#else
42	ldr     r2, .Lhwcap
43	ldr     r2, [r2, #0]
44#endif
45
46#ifdef __SOFTFP__
47	tst     r2, #HWCAP_ARM_VFP
48	beq     .Lno_vfp_sc
49#endif
50
51	/* Following instruction is vldmia r0!, {d8-d15}.  */
52	ldc     p11, cr8, [r0], #64
53	/* Restore the floating-point status register.  */
54	ldr     r1, [r0], #4
55	/* Following instruction is fmxr fpscr, r1.  */
56	mcr     p10, 7, r1, cr1, cr0, 0
57.Lno_vfp_sc:
58	tst     r2, #HWCAP_ARM_IWMMXT
59	beq     .Lno_iwmmxt_sc
60
61	/* Restore the call-preserved iWMMXt registers.  */
62	/* Following instructions are wldrd wr10, [r0], #8 (etc.)  */
63	ldcl    p1, cr10, [r0], #8
64	ldcl    p1, cr11, [r0], #8
65	ldcl    p1, cr12, [r0], #8
66	ldcl    p1, cr13, [r0], #8
67	ldcl    p1, cr14, [r0], #8
68	ldcl    p1, cr15, [r0], #8
69.Lno_iwmmxt_sc:
70
71	/* Now bring back the signal status.  */
72	mov	r0, #SIG_SETMASK
73	add	r1, r4, #UCONTEXT_SIGMASK
74	mov	r2, #0
75	bl	PLTJMP(__sigprocmask)
76
77	/* Loading r0-r3 makes makecontext easier.  */
78	add     r14, r4, #MCONTEXT_ARM_R0
79	ldmia   r14, {r0-r12}
80	ldr     r13, [r14, #(MCONTEXT_ARM_SP - MCONTEXT_ARM_R0)]
81	add     r14, r14, #(MCONTEXT_ARM_LR - MCONTEXT_ARM_R0)
82	ldmia   r14, {r14, pc}
83
84END(setcontext)
85weak_alias(__setcontext, setcontext)
86
87	/* Called when a makecontext() context returns.  Start the
88	   context in R4 or fall through to exit().  */
89	/* Unwind descriptors are looked up based on PC - 2, so we have to
90	   make sure to mark the instruction preceding the __startcontext
91	   label as .cantunwind.  */
92	.fnstart
93	.cantunwind
94	nop
95ENTRY(__startcontext)
96	movs    r0, r4
97	bne     PLTJMP(__setcontext)
98
99	@ New context was 0 - exit
100	b       PLTJMP(HIDDEN_JUMPTARGET(exit))
101	.fnend
102END(__startcontext)
103
104#ifdef SHARED
1051:      .long   _GLOBAL_OFFSET_TABLE_ - 0b - PC_OFS
106.Lrtld_global_ro:
107	.long   C_SYMBOL_NAME(_rtld_global_ro)(GOT)
108#else
109.Lhwcap:
110	.long   C_SYMBOL_NAME(_dl_hwcap)
111#endif
112