Currently selecting CONFIG_POSITION_INDEPENDENT also forces us to use an initial stack pointer relative to the beginning of the BSS section. This makes some sense, because this should be writable memory anyway.
However the BSS section is not cleared or used until later in the setup process (after relocation), so memory nearby might not be available early enough to host the initial stack. This is an issue if U-Boot is loaded from (Flash-)ROM, for instance.
Allow CONFIG_INIT_SP_RELATIVE to be turned off by a board's config, to be able to select a fixed stack pointer, for instance in known good DRAM.
This will help QEMU utilising PIE, when it's loaded to (Flash-)ROM.
Signed-off-by: Andre Przywara andre.przywara@arm.com Reviewed-by: Stephen Warren swarren@nvidia.com --- arch/arm/Kconfig | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/arch/arm/Kconfig b/arch/arm/Kconfig index b6fb276b6f8..486141478ce 100644 --- a/arch/arm/Kconfig +++ b/arch/arm/Kconfig @@ -12,7 +12,6 @@ config ARM64 if ARM64 config POSITION_INDEPENDENT bool "Generate position-independent pre-relocation code" - select INIT_SP_RELATIVE 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 @@ -23,6 +22,7 @@ config POSITION_INDEPENDENT
config INIT_SP_RELATIVE bool "Specify the early stack pointer relative to the .bss section" + default y if POSITION_INDEPENDENT help U-Boot typically uses a hard-coded value for the stack pointer before relocation. Enable this option to instead calculate the