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arm64: Add support for larger PIE U-Boot

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Linking a U-Boot larger than 1MB fails with PIE enabled:
u-boot/arch/arm/cpu/armv8/start.S:71:(.text+0x3c): relocation
truncated to fit: R_AARCH64_ADR_PREL_LO21 against symbol `__rel_dyn_end'
defined in .bss_start section in u-boot.

This extends the supported range by using adrp & add to load symbols
early while starting up.

Signed-off-by: Edgar E. Iglesias <edgar.iglesias@xilinx.com>
Reviewed-by: Stephen Warren <swarren@nvidia.com>
Tested-by: Michal Simek <michal.simek@xilinx.com>
Signed-off-by: Michal Simek <michal.simek@xilinx.com>
This commit is contained in:
Edgar E. Iglesias 2020-09-09 19:07:26 +02:00 committed by Michal Simek
parent 04d13b5d09
commit 28c851f128
2 changed files with 11 additions and 3 deletions
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6
arch/arm/cpu/armv8/start.S
View File

@ -84,8 +84,10 @@ pie_fixup:
adr x0, _start /* x0 <- Runtime value of _start */
ldr x1, _TEXT_BASE /* x1 <- Linked value of _start */
sub x9, x0, x1 /* x9 <- Run-vs-link offset */
adr x2, __rel_dyn_start /* x2 <- Runtime &__rel_dyn_start */
adr x3, __rel_dyn_end /* x3 <- Runtime &__rel_dyn_end */
adrp x2, __rel_dyn_start /* x2 <- Runtime &__rel_dyn_start */
add x2, x2, #:lo12:__rel_dyn_start
adrp x3, __rel_dyn_end /* x3 <- Runtime &__rel_dyn_end */
add x3, x3, #:lo12:__rel_dyn_end
pie_fix_loop:
ldp x0, x1, [x2], #16 /* (x0, x1) <- (Link location, fixup) */
ldr x4, [x2], #8 /* x4 <- addend */

8
arch/arm/lib/crt0_64.S
View File

@ -73,7 +73,12 @@ ENTRY(_main)
#elif defined(CONFIG_SPL_BUILD) && defined(CONFIG_SPL_STACK)
ldr x0, =(CONFIG_SPL_STACK)
#elif defined(CONFIG_INIT_SP_RELATIVE)
#if CONFIG_POSITION_INDEPENDENT
adrp x0, __bss_start /* x0 <- Runtime &__bss_start */
add x0, x0, #:lo12:__bss_start
#else
adr x0, __bss_start
#endif
add x0, x0, #CONFIG_SYS_INIT_SP_BSS_OFFSET
#else
ldr x0, =(CONFIG_SYS_INIT_SP_ADDR)
@ -102,7 +107,8 @@ ENTRY(_main)
adr lr, relocation_return
#if CONFIG_POSITION_INDEPENDENT
/* Add in link-vs-runtime offset */
adr x0, _start /* x0 <- Runtime value of _start */
adrp x0, _start /* x0 <- Runtime value of _start */
add x0, x0, #:lo12:_start
ldr x9, _TEXT_BASE /* x9 <- Linked value of _start */
sub x9, x9, x0 /* x9 <- Run-vs-link offset */
add lr, lr, x9