summaryrefslogtreecommitdiffstats
path: root/arch/arm/lib/relocate.S
blob: 475d503dd9df63fda046d225c47205a1bc9c80af (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
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
/*
 *  relocate - common relocation function for ARM U-Boot
 *
 *  Copyright (c) 2013  Albert ARIBAUD <albert.u.boot@aribaud.net>
 *
 * SPDX-License-Identifier:	GPL-2.0+
 */

#include <asm-offsets.h>
#include <config.h>
#include <linux/linkage.h>
#ifdef CONFIG_CPU_V7M
#include <asm/armv7m.h>
#endif

/*
 * Default/weak exception vectors relocation routine
 *
 * This routine covers the standard ARM cases: normal (0x00000000),
 * high (0xffff0000) and VBAR. SoCs which do not comply with any of
 * the standard cases must provide their own, strong, version.
 */

	.section	.text.relocate_vectors,"ax",%progbits
	.weak		relocate_vectors

ENTRY(relocate_vectors)

#ifdef CONFIG_CPU_V7M
	/*
	 * On ARMv7-M we only have to write the new vector address
	 * to VTOR register.
	 */
	ldr	r0, [r9, #GD_RELOCADDR]	/* r0 = gd->relocaddr */
	ldr	r1, =V7M_SCB_BASE
	str	r0, [r1, V7M_SCB_VTOR]
#else
#ifdef CONFIG_HAS_VBAR
	/*
	 * If the ARM processor has the security extensions,
	 * use VBAR to relocate the exception vectors.
	 */
	ldr	r0, [r9, #GD_RELOCADDR]	/* r0 = gd->relocaddr */
	mcr     p15, 0, r0, c12, c0, 0  /* Set VBAR */
#else
	/*
	 * Copy the relocated exception vectors to the
	 * correct address
	 * CP15 c1 V bit gives us the location of the vectors:
	 * 0x00000000 or 0xFFFF0000.
	 */
	ldr	r0, [r9, #GD_RELOCADDR]	/* r0 = gd->relocaddr */
	mrc	p15, 0, r2, c1, c0, 0	/* V bit (bit[13]) in CP15 c1 */
	ands	r2, r2, #(1 << 13)
	ldreq	r1, =0x00000000		/* If V=0 */
	ldrne	r1, =0xFFFF0000		/* If V=1 */
	ldmia	r0!, {r2-r8,r10}
	stmia	r1!, {r2-r8,r10}
	ldmia	r0!, {r2-r8,r10}
	stmia	r1!, {r2-r8,r10}
#endif
#endif
	bx	lr

ENDPROC(relocate_vectors)

/*
 * void relocate_code(addr_moni)
 *
 * This function relocates the monitor code.
 *
 * NOTE:
 * To prevent the code below from containing references with an R_ARM_ABS32
 * relocation record type, we never refer to linker-defined symbols directly.
 * Instead, we declare literals which contain their relative location with
 * respect to relocate_code, and at run time, add relocate_code back to them.
 */

ENTRY(relocate_code)
	ldr	r1, =__image_copy_start	/* r1 <- SRC &__image_copy_start */
	subs	r4, r0, r1		/* r4 <- relocation offset */
	beq	relocate_done		/* skip relocation */
	ldr	r2, =__image_copy_end	/* r2 <- SRC &__image_copy_end */

copy_loop:
	ldmia	r1!, {r10-r11}		/* copy from source address [r1]    */
	stmia	r0!, {r10-r11}		/* copy to   target address [r0]    */
	cmp	r1, r2			/* until source end address [r2]    */
	blo	copy_loop

	/*
	 * fix .rel.dyn relocations
	 */
	ldr	r2, =__rel_dyn_start	/* r2 <- SRC &__rel_dyn_start */
	ldr	r3, =__rel_dyn_end	/* r3 <- SRC &__rel_dyn_end */
fixloop:
	ldmia	r2!, {r0-r1}		/* (r0,r1) <- (SRC location,fixup) */
	and	r1, r1, #0xff
	cmp	r1, #23			/* relative fixup? */
	bne	fixnext

	/* relative fix: increase location by offset */
	add	r0, r0, r4
	ldr	r1, [r0]
	add	r1, r1, r4
	str	r1, [r0]
fixnext:
	cmp	r2, r3
	blo	fixloop

relocate_done:

#ifdef __XSCALE__
	/*
	 * On xscale, icache must be invalidated and write buffers drained,
	 * even with cache disabled - 4.2.7 of xscale core developer's manual
	 */
	mcr	p15, 0, r0, c7, c7, 0	/* invalidate icache */
	mcr	p15, 0, r0, c7, c10, 4	/* drain write buffer */
#endif

	/* ARMv4- don't know bx lr but the assembler fails to see that */

#ifdef __ARM_ARCH_4__
	mov	pc, lr
#else
	bx	lr
#endif

ENDPROC(relocate_code)
OpenPOWER on IntegriCloud