Use Kconfig 'depends on' instead of #if macro to express the option depdencies.

Signed-off-by: Chia-Wei Wang chiawei_wang@aspeedtech.com --- arch/arm/Kconfig | 9 +++++---- 1 file changed, 5 insertions(+), 4 deletions(-)

diff --git a/arch/arm/Kconfig b/arch/arm/Kconfig index 2b7b625705..c142eaa5c1 100644 --- a/arch/arm/Kconfig +++ b/arch/arm/Kconfig @@ -9,9 +9,9 @@ config ARM64 select PHYS_64BIT select SYS_CACHE_SHIFT_6

-if ARM64 config POSITION_INDEPENDENT bool "Generate position-independent pre-relocation code" + depends on ARM64 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 @@ -22,6 +22,7 @@ config POSITION_INDEPENDENT

config INIT_SP_RELATIVE bool "Specify the early stack pointer relative to the .bss section" + depends on ARM64 default n if ARCH_QEMU default y if POSITION_INDEPENDENT help @@ -37,6 +38,7 @@ config INIT_SP_RELATIVE

config SYS_INIT_SP_BSS_OFFSET int "Early stack offset from the .bss base address" + depends on ARM64 depends on INIT_SP_RELATIVE default 524288 help @@ -46,6 +48,7 @@ config SYS_INIT_SP_BSS_OFFSET do not overlap any appended DTB.

config LINUX_KERNEL_IMAGE_HEADER + depends on ARM64 bool help Place a Linux kernel image header at the start of the U-Boot binary. @@ -54,14 +57,12 @@ config LINUX_KERNEL_IMAGE_HEADER image header reports the amount of memory (BSS and similar) that U-Boot needs to use, but which isn't part of the binary.

-if LINUX_KERNEL_IMAGE_HEADER config LNX_KRNL_IMG_TEXT_OFFSET_BASE + depends on LINUX_KERNEL_IMAGE_HEADER hex help The value subtracted from CONFIG_SYS_TEXT_BASE to calculate the TEXT_OFFSET value written to the Linux kernel image header. -endif -endif

config GIC_V3_ITS bool "ARM GICV3 ITS"

A U-Boot image could be loaded and executed at a different location than it was linked at.

For example, Aspeed takes a stable release version of U-Boot image as the golden one for recovery purposes. When the primary storage such as flash is corrupted, the golden image would be loaded to any SRAM/DRAM address on demands through ethernet/UART/etc and run for rescue.

To deal with this condition, the PIE is needed as there is only one signed, golden image, which could be however executed at different places.

This patch adds the PIE support for ARMv7 platform.

Signed-off-by: Chia-Wei Wang chiawei_wang@aspeedtech.com --- arch/arm/Kconfig | 2 +- arch/arm/cpu/armv7/start.S | 43 ++++++++++++++++++++++++++++++++++++++ arch/arm/lib/crt0.S | 11 ++++++++++ arch/arm/lib/relocate.S | 35 ++++++++++++++++++++++--------- 4 files changed, 80 insertions(+), 11 deletions(-)

diff --git a/arch/arm/Kconfig b/arch/arm/Kconfig index c142eaa5c1..d653f64c47 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 dcb4195d7b..3c0b2d6a71 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