From: "Edgar E. Iglesias" edgar.iglesias@xilinx.com
PIE requires a 4K aligned load address. If this is not met, trap the startup sequence in a WFI loop rather than running into obscure failures.
Tested-by: Michal Simek michal.simek@xilinx.com Suggested-by: André Przywara andre.przywara@arm.com Signed-off-by: Edgar E. Iglesias edgar.iglesias@xilinx.com --- arch/arm/cpu/armv8/start.S | 17 +++++++++++++++++ 1 file changed, 17 insertions(+)
diff --git a/arch/arm/cpu/armv8/start.S b/arch/arm/cpu/armv8/start.S index 002698b501..732bc385d4 100644 --- a/arch/arm/cpu/armv8/start.S +++ b/arch/arm/cpu/armv8/start.S @@ -59,6 +59,23 @@ reset: save_boot_params_ret:
#if CONFIG_POSITION_INDEPENDENT + /* Verify that we're 4K aligned. */ + adr x1, _start + ands x1, x1, #0xfff + b.eq 1f +0: + /* + * FATAL, can't continue. + * U-boot needs to be loaded at a 4K aligned address. + * + * We use ADRP and ADD to load some symbol addresses during startup. + * The ADD uses an absolute (non pc-relative) lo12 relocation + * thus requiring 4K alignment. + */ + wfi + b 0b +1: + /* * Fix .rela.dyn relocations. This allows U-Boot to be loaded to and * executed at a different address than it was linked at.