[PATCH] armv8: Skip PIE in SPL due to load alignment fault.

When PIE is enabled in start.S, u-boot/-spl use __rel_dyn_start and _rel_dyn_end symbol to be loaded to and executed at a different address than it was linked at.
u-boot-spl.lds is used in SPL build, but relocation information section(.rela*) were discarded. In line number 80 in arch/arm/cpu/armv8/u-boot-spl.lds /DISCARD/ : { *(.rela*) }
If PIE enabled in SPL, __rel_dyn_start which is defined as .rel_dyn_start in sections.c will be apended to the end of .bss section.
In our ASPEED case, size of .bss section would let .rel_dyn_start without 8-byte alignment, leading to alignment fault when executing ldp instuction in pie_fix_loop.
Signed-off-by: Kevin Chen kevin_chen@aspeedtech.com --- arch/arm/cpu/armv8/start.S | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/arch/arm/cpu/armv8/start.S b/arch/arm/cpu/armv8/start.S index f3ea858577..6cc1d26e5e 100644 --- a/arch/arm/cpu/armv8/start.S +++ b/arch/arm/cpu/armv8/start.S @@ -58,7 +58,7 @@ reset: .globl save_boot_params_ret save_boot_params_ret:
-#if CONFIG_POSITION_INDEPENDENT +#if CONFIG_POSITION_INDEPENDENT && !defined(CONFIG_SPL_BUILD) /* Verify that we're 4K aligned. */ adr x0, _start ands x0, x0, #0xfff

On Thu, Aug 03, 2023 at 04:12:18PM +0800, Kevin Chen wrote:
When PIE is enabled in start.S, u-boot/-spl use __rel_dyn_start and _rel_dyn_end symbol to be loaded to and executed at a different address than it was linked at.
u-boot-spl.lds is used in SPL build, but relocation information section(.rela*) were discarded. In line number 80 in arch/arm/cpu/armv8/u-boot-spl.lds /DISCARD/ : { *(.rela*) }
If PIE enabled in SPL, __rel_dyn_start which is defined as .rel_dyn_start in sections.c will be apended to the end of .bss section.
In our ASPEED case, size of .bss section would let .rel_dyn_start without 8-byte alignment, leading to alignment fault when executing ldp instuction in pie_fix_loop.
Signed-off-by: Kevin Chen kevin_chen@aspeedtech.com
Applied to u-boot/next, thanks!
participants (2)
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Kevin Chen
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Tom Rini