Re: [U-Boot] [PATCH 3/4] arm64: Non-manual relocation

This turns off CONFIG_NEEDS_MANUAL_RELOC and turns on -pie.

The bss part of the linker script is changed to be more like arm32, as the previous arm64 approach was generating bad relocations (even readelf didn't like them).

relocate_64.S is made to look more like relocate.S, and then changed to support RELA style relocations rather than REL.

Signed-off-by: Scott Wood scottwood@freescale.com

arch/arm/config.mk | 2 -- arch/arm/cpu/armv8/config.mk | 1 - arch/arm/cpu/armv8/u-boot.lds | 32 +++++++++++++++++++++++------- arch/arm/include/asm/config.h | 5 ----- arch/arm/lib/crt0_64.S | 7 ++----- arch/arm/lib/relocate_64.S | 41 ++++++++++++++++++++------------------- include/configs/vexpress_aemv8a.h | 3 +++ 7 files changed, 51 insertions(+), 40 deletions(-)

diff --git a/arch/arm/config.mk b/arch/arm/config.mk index 95c07ad..96d2d88 100644 --- a/arch/arm/config.mk +++ b/arch/arm/config.mk @@ -74,9 +74,7 @@ endif endif

# needed for relocation -ifndef CONFIG_ARM64 LDFLAGS_u-boot += -pie -endif

# # FIXME: binutils versions < 2.22 have a bug in the assembler where diff --git a/arch/arm/cpu/armv8/config.mk b/arch/arm/cpu/armv8/config.mk index 9f36d59..027a68c 100644 --- a/arch/arm/cpu/armv8/config.mk +++ b/arch/arm/cpu/armv8/config.mk @@ -13,4 +13,3 @@ PLATFORM_NO_UNALIGNED := $(PF_NO_UNALIGNED) PF_CPPFLAGS_ARMV8 := $(call cc-option, -march=armv8-a) PLATFORM_CPPFLAGS += $(PF_CPPFLAGS_ARMV8) PLATFORM_CPPFLAGS += $(PF_NO_UNALIGNED) -PLATFORM_CPPFLAGS += -fpic diff --git a/arch/arm/cpu/armv8/u-boot.lds b/arch/arm/cpu/armv8/u-boot.lds index 328d477..4c12222 100644 --- a/arch/arm/cpu/armv8/u-boot.lds +++ b/arch/arm/cpu/armv8/u-boot.lds @@ -41,25 +41,43 @@ SECTIONS }

. = ALIGN(8);

• .reloc : {

• __rel_got_start = .;
  

• *(.got)
  

• __rel_got_end = .;
  

• }

  .image_copy_end : { *(.__image_copy_end) }

• . = ALIGN(8);

• .rel_dyn_start :

• {

• *(.__rel_dyn_start)
  

• }

• .rela.dyn : {

• *(.rela*)
  

• }

• .rel_dyn_end :

• {

• *(.__rel_dyn_end)
  

• }

• _end = .;

  . = ALIGN(8);

• .bss_start : {

• KEEP(*(.__bss_start));
  

• }

• .bss : {

• __bss_start = .;
  

  *(.bss*) . = ALIGN(8);

• __bss_end = .;
  

• }

• .bss_end : {

• KEEP(*(.__bss_end));
  

  }

  /DISCARD/ : { *(.dynsym) }

diff --git a/arch/arm/include/asm/config.h b/arch/arm/include/asm/config.h index 0ee131d..de4d01e 100644 --- a/arch/arm/include/asm/config.h +++ b/arch/arm/include/asm/config.h @@ -11,11 +11,6 @@ #define CONFIG_SYS_BOOT_RAMDISK_HIGH

#ifdef CONFIG_ARM64 -/*

• • Currently, GOT is used to relocate u-boot and
• • configuration CONFIG_NEEDS_MANUAL_RELOC is needed.
• */

-#define CONFIG_NEEDS_MANUAL_RELOC #define CONFIG_PHYS_64BIT #endif

diff --git a/arch/arm/lib/crt0_64.S b/arch/arm/lib/crt0_64.S index ddd46eb..7756396 100644 --- a/arch/arm/lib/crt0_64.S +++ b/arch/arm/lib/crt0_64.S @@ -94,11 +94,8 @@ relocation_return: /*

• Clear BSS section

*/

• ldr x9, [x18, #GD_RELOC_OFF] /* x9 <- gd->reloc_off */
• ldr x0, =__bss_start
• add x0, x0, x9 /* x0 <- __bss_start in RAM */
• ldr x1, =__bss_end
• add x1, x1, x9 /* x1 <- __bss_end in RAM */

• ldr x0, =__bss_start /* this is auto-relocated! */
• ldr x1, =__bss_end /* this is auto-relocated! */ mov x2, #0

clear_loop: str x2, [x0] diff --git a/arch/arm/lib/relocate_64.S b/arch/arm/lib/relocate_64.S index 29c3239..7fba9e2 100644 --- a/arch/arm/lib/relocate_64.S +++ b/arch/arm/lib/relocate_64.S @@ -16,40 +16,41 @@

• void relocate_code (addr_moni)
• This function relocates the monitor code.

• • NOTE:
• • GOT is used and configuration CONFIG_NEEDS_MANUAL_RELOC is needed.

• • x0 holds the destination address.
  */

ENTRY(relocate_code) /* * Copy u-boot from flash to RAM */

• ldr x1, =__image_copy_start /* x1 <- copy source */
• cmp x1, x0

• ldr x1, =__image_copy_start /* x1 <- SRC &__image_copy_start */
• subs x9, x0, x1 /* x9 <- relocation offset */ b.eq relocate_done /* skip relocation */

• mov x2, x0 /* x2 <- copy destination */
• ldr x3, =__image_copy_end /* x3 <- source end address */

• ldr x2, =__image_copy_end /* x2 <- SRC &__image_copy_end */

copy_loop: ldp x10, x11, [x1], #16 /* copy from source address [x1] */

• stp x10, x11, [x2], #16 /* copy to target address [x2] */
• cmp x1, x3 /* until source end address [x3] */

• stp x10, x11, [x0], #16 /* copy to target address [x0] */

• cmp x1, x2 /* until source end address [x2] */ b.lo copy_loop

  /*

• * Fix .reloc relocations
  

• * Fix .rela.dyn relocations
  

  */

• ldr x9, [x18, #GD_RELOC_OFF]/* x9 <- relocation offset */
• ldr x1, =__rel_got_start /* x1 <- rel got start ofs */
• add x1, x1, x9 /* x1 <- rel got start in RAM */
• ldr x2, =__rel_got_end /* x2 <- rel got end ofs */
• add x2, x2, x9 /* x2 <- rel got end in RAM */

• ldr x2, =__rel_dyn_start /* x2 <- SRC &__rel_dyn_start */
• ldr x3, =__rel_dyn_end /* x3 <- SRC &__rel_dyn_end */

fixloop:

• ldr x10, [x1]
• add x10, x10, x9 /* x10 <- address to be fixed up */
• str x10, [x1]
• add x1, x1, #8 /* each got entry is 8 bytes */
• cmp x1, x2

• ldp x0, x1, [x2], #16 /* (x0,x1) <- (SRC location, fixup) */
• ldr x4, [x2], #8 /* x4 <- addend */
• and x1, x1, #0xffffffff
• cmp x1, #1027 /* relative fixup? */
• bne fixnext
• /* relative fix: store addend plus offset at dest location */
• add x0, x0, x9
• add x4, x4, x9
• str x4, [x0]

+fixnext:

• cmp x2, x3 b.lo fixloop

relocate_done: diff --git a/include/configs/vexpress_aemv8a.h b/include/configs/vexpress_aemv8a.h index 01c95f5..3932e00 100644 --- a/include/configs/vexpress_aemv8a.h +++ b/include/configs/vexpress_aemv8a.h @@ -10,6 +10,9 @@

#define DEBUG

+#define CONFIG_REMAKE_ELF +#define CONFIG_STATIC_RELA

CONFIG_STATIC_RELA is always needed, How about remove this macro.

David,