On Mon, Aug 02, 2021 at 06:44:57PM +0800, Chia-Wei Wang wrote:
A U-Boot image could be loaded and executed at a different location than it was linked at.
For example, Aspeed takes a stable release version of U-Boot image as the golden one for recovery purposes. When the primary storage such as flash is corrupted, the golden image could be loaded to any SRAM/DRAM address on demands through ethernet/UART/etc.
To deal with this condition, the PIE is needed as there is only one signed, golden image, which could be however executed at different places.
This patch adds the PIE support for ARMv7 platform.
Signed-off-by: Chia-Wei Wang chiawei_wang@aspeedtech.com
arch/arm/Kconfig | 4 +++- arch/arm/cpu/armv7/start.S | 43 ++++++++++++++++++++++++++++++++++++++ arch/arm/lib/crt0.S | 11 ++++++++++ arch/arm/lib/relocate.S | 35 ++++++++++++++++++++++--------- 4 files changed, 82 insertions(+), 11 deletions(-)
diff --git a/arch/arm/Kconfig b/arch/arm/Kconfig index 2b7b625705..45879c9f06 100644 --- a/arch/arm/Kconfig +++ b/arch/arm/Kconfig @@ -9,7 +9,7 @@ config ARM64 select PHYS_64BIT select SYS_CACHE_SHIFT_6
-if ARM64 +if ARM64 || CPU_V7A config POSITION_INDEPENDENT bool "Generate position-independent pre-relocation code" help
Thanks for doing this. I think we need to fix the depends on lines here rather than hide with if ARM64 || CPU_V7A, and then fix anything else that follows to also have the correct dependencies.