diff options
Diffstat (limited to 'arch/arm/lib')
| -rw-r--r-- | arch/arm/lib/Makefile | 1 | ||||
| -rw-r--r-- | arch/arm/lib/relocate.S | 112 |
2 files changed, 113 insertions, 0 deletions
diff --git a/arch/arm/lib/Makefile b/arch/arm/lib/Makefile index 5b2cb61dc..8ad9f66a5 100644 --- a/arch/arm/lib/Makefile +++ b/arch/arm/lib/Makefile @@ -39,6 +39,7 @@ GLCOBJS += div0.o SOBJS-y += crt0.o ifndef CONFIG_SPL_BUILD +SOBJS-y += relocate.o ifndef CONFIG_SYS_GENERIC_BOARD COBJS-y += board.o endif diff --git a/arch/arm/lib/relocate.S b/arch/arm/lib/relocate.S new file mode 100644 index 000000000..4446da94c --- /dev/null +++ b/arch/arm/lib/relocate.S @@ -0,0 +1,112 @@ +/* + * relocate - common relocation function for ARM U-Boot + * + * Copyright (c) 2013 Albert ARIBAUD <albert.u.boot@aribaud.net> + * + * See file CREDITS for list of people who contributed to this + * project. + * + * This program is free software; you can redistribute it and/or + * modify it under the terms of the GNU General Public License as + * published by the Free Software Foundation; either version 2 of + * the License, or (at your option) any later version. + * + * This program 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 General Public License for more details. + * + * You should have received a copy of the GNU General Public License + * along with this program; if not, write to the Free Software + * Foundation, Inc., 59 Temple Place, Suite 330, Boston, + * MA 02111-1307 USA + */ + +#include <linux/linkage.h> + +/* + * 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) + mov r6, r0 /* save addr of destination */ + + ldr r0, =_start /* r0 <- SRC &_start */ + subs r9, r6, r0 /* r9 <- relocation offset */ + beq relocate_done /* skip relocation */ + mov r1, r6 /* r1 <- scratch for copy loop */ + adr r7, relocate_code /* r7 <- SRC &relocate_code */ + ldr r3, _image_copy_end_ofs /* r3 <- __image_copy_end local ofs */ + add r2, r7, r3 /* r2 <- SRC &__image_copy_end */ + +copy_loop: + ldmia r0!, {r10-r11} /* copy from source address [r0] */ + stmia r1!, {r10-r11} /* copy to target address [r1] */ + cmp r0, r2 /* until source end address [r2] */ + blo copy_loop + + /* + * fix .rel.dyn relocations + */ + ldr r10, _dynsym_start_ofs /* r10 <- __dynsym_start local ofs */ + add r10, r10, r7 /* r10 <- SRC &__dynsym_start */ + ldr r2, _rel_dyn_start_ofs /* r2 <- __rel_dyn_start local ofs */ + add r2, r2, r7 /* r2 <- SRC &__rel_dyn_start */ + ldr r3, _rel_dyn_end_ofs /* r3 <- __rel_dyn_end local ofs */ + add r3, r3, r7 /* r3 <- SRC &__rel_dyn_end */ +fixloop: + ldr r0, [r2] /* r0 <- SRC location to fix up */ + add r0, r0, r9 /* r0 <- DST location to fix up */ + ldr r1, [r2, #4] + and r7, r1, #0xff + cmp r7, #23 /* relative fixup? */ + beq fixrel + cmp r7, #2 /* absolute fixup? */ + beq fixabs + /* ignore unknown type of fixup */ + b fixnext +fixabs: + /* absolute fix: set location to (offset) symbol value */ + mov r1, r1, LSR #4 /* r1 <- symbol index in .dynsym */ + add r1, r10, r1 /* r1 <- address of symbol in table */ + ldr r1, [r1, #4] /* r1 <- symbol value */ + add r1, r1, r9 /* r1 <- relocated sym addr */ + b fixnext +fixrel: + /* relative fix: increase location by offset */ + ldr r1, [r0] + add r1, r1, r9 +fixnext: + str r1, [r0] + add r2, r2, #8 /* each rel.dyn entry is 8 bytes */ + cmp r2, r3 + blo fixloop + +relocate_done: + + /* ARMv4- don't know bx lr but the assembler fails to see that */ + +#ifdef __ARM_ARCH_4__ + mov pc, lr +#else + bx lr +#endif + +_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 +_dynsym_start_ofs: + .word __dynsym_start - relocate_code + +ENDPROC(relocate_code) |