diff options
| -rw-r--r-- | arch/arm/Kconfig | 2 | ||||
| -rw-r--r-- | arch/arm/cpu/armv7/start.S | 43 | ||||
| -rw-r--r-- | arch/arm/lib/crt0.S | 11 | ||||
| -rw-r--r-- | arch/arm/lib/relocate.S | 35 |
4 files changed, 80 insertions, 11 deletions
diff --git a/arch/arm/Kconfig b/arch/arm/Kconfig index 31ae2950ee..50efb5e2e2 100644 --- a/arch/arm/Kconfig +++ b/arch/arm/Kconfig @@ -11,7 +11,7 @@ config ARM64 config POSITION_INDEPENDENT bool "Generate position-independent pre-relocation code" - depends on ARM64 + depends on ARM64 || CPU_V7A help U-Boot expects to be linked to a specific hard-coded address, and to be loaded to and run from that address. This option lifts that diff --git a/arch/arm/cpu/armv7/start.S b/arch/arm/cpu/armv7/start.S index 87329d26e1..698e15b8e1 100644 --- a/arch/arm/cpu/armv7/start.S +++ b/arch/arm/cpu/armv7/start.S @@ -39,6 +39,42 @@ reset: /* Allow the board to save important registers */ b save_boot_params save_boot_params_ret: +#ifdef CONFIG_POSITION_INDEPENDENT + /* + * Fix .rela.dyn relocations. This allows U-Boot to loaded to and + * executed at a different address than it was linked at. + */ +pie_fixup: + adr r0, reset /* r0 <- Runtime value of reset label */ + ldr r1, =reset /* r1 <- Linked value of reset label */ + subs r4, r0, r1 /* r4 <- Runtime-vs-link offset */ + beq pie_fixup_done + + adr r0, pie_fixup + ldr r1, _rel_dyn_start_ofs + add r2, r0, r1 /* r2 <- Runtime &__rel_dyn_start */ + ldr r1, _rel_dyn_end_ofs + add r3, r0, r1 /* r3 <- Runtime &__rel_dyn_end */ + +pie_fix_loop: + ldr r0, [r2] /* r0 <- Link location */ + ldr r1, [r2, #4] /* r1 <- fixup */ + cmp r1, #23 /* relative fixup? */ + bne pie_skip_reloc + + /* relative fix: increase location by offset */ + add r0, r4 + ldr r1, [r0] + add r1, r4 + str r1, [r0] + str r0, [r2] + add r2, #8 +pie_skip_reloc: + cmp r2, r3 + blo pie_fix_loop +pie_fixup_done: +#endif + #ifdef CONFIG_ARMV7_LPAE /* * check for Hypervisor support @@ -340,3 +376,10 @@ ENTRY(cpu_init_crit) b lowlevel_init @ go setup pll,mux,memory ENDPROC(cpu_init_crit) #endif + +#if CONFIG_POSITION_INDEPENDENT +_rel_dyn_start_ofs: + .word __rel_dyn_start - pie_fixup +_rel_dyn_end_ofs: + .word __rel_dyn_end - pie_fixup +#endif diff --git a/arch/arm/lib/crt0.S b/arch/arm/lib/crt0.S index 46b6be21a8..956d258c9d 100644 --- a/arch/arm/lib/crt0.S +++ b/arch/arm/lib/crt0.S @@ -130,6 +130,14 @@ ENTRY(_main) ldr r9, [r9, #GD_NEW_GD] /* r9 <- gd->new_gd */ adr lr, here +#if defined(CONFIG_POSITION_INDEPENDENT) + adr r0, _main + ldr r1, _start_ofs + add r0, r1 + ldr r1, =CONFIG_SYS_TEXT_BASE + sub r1, r0 + add lr, r1 +#endif ldr r0, [r9, #GD_RELOC_OFF] /* r0 = gd->reloc_off */ add lr, lr, r0 #if defined(CONFIG_CPU_V7M) @@ -180,3 +188,6 @@ here: #endif ENDPROC(_main) + +_start_ofs: + .word _start - _main diff --git a/arch/arm/lib/relocate.S b/arch/arm/lib/relocate.S index e5f7267be1..14b7f61c1a 100644 --- a/arch/arm/lib/relocate.S +++ b/arch/arm/lib/relocate.S @@ -78,22 +78,28 @@ ENDPROC(relocate_vectors) */ 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 */ - + 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] */ + 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 */ + 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 @@ -129,3 +135,12 @@ relocate_done: #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 |