u-boot/arch/arm/lib/relocate.S

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/* SPDX-License-Identifier: GPL-2.0+ */
/*
* relocate - common relocation function for ARM U-Boot
*
* Copyright (c) 2013 Albert ARIBAUD <albert.u.boot@aribaud.net>
*/
#include <asm-offsets.h>
#include <asm/assembler.h>
#include <config.h>
#include <elf.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)
adr r3, relocate_code
ldr r1, _image_copy_start_ofs
add r1, r3 /* r1 <- Run &__image_copy_start */
subs r4, r0, r1 /* r4 <- Run to copy offset */
beq relocate_done /* skip relocation */
ldr r1, _image_copy_start_ofs
add r1, r3 /* r1 <- Run &__image_copy_start */
ldr r2, _image_copy_end_ofs
add r2, r3 /* r2 <- Run &__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 r1, _rel_dyn_start_ofs
add r2, r1, r3 /* r2 <- Run &__rel_dyn_start */
ldr r1, _rel_dyn_end_ofs
add r3, r1, r3 /* r3 <- Run &__rel_dyn_end */
fixloop:
ldmia r2!, {r0-r1} /* (r0,r1) <- (SRC location,fixup) */
and r1, r1, #0xff
cmp r1, #R_ARM_RELATIVE
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)
_image_copy_start_ofs:
.word __image_copy_start - relocate_code
_image_copy_end_ofs:
.word __image_copy_end - relocate_code
_rel_dyn_start_ofs:
.word __rel_dyn_start - relocate_code
_rel_dyn_end_ofs:
.word __rel_dyn_end - relocate_code