[PATCH v2 6/6] qemu-arm64: Enable POSITION_INDEPENDENT

Andre Przywara
2020-09-30T16:39:18Z

Now that PIE works when U-Boot is started from ROM, let's enable
CONFIG_POSITION_INDEPENDENT, which allows to load U-Boot also via
ARM Trusted-Firmware's fip.bin to DRAM, without tweaking the
configuration.

To get a writable initial stack, we need to keep the fixed initial
stack pointer, which points to DRAM in our case.

Signed-off-by: Andre Przywara <andre.przywara@arm.com>
Reviewed-by: Stephen Warren <swarren@nvidia.com>
---
arch/arm/Kconfig | 1 +
configs/qemu_arm64_defconfig | 1 +
2 files changed, 2 insertions(+)

diff --git a/arch/arm/Kconfig b/arch/arm/Kconfig
index 5ffa84c1d98..8ba73680699 100644
--- a/arch/arm/Kconfig
+++ b/arch/arm/Kconfig
@@ -22,6 +22,7 @@ config POSITION_INDEPENDENT

config INIT_SP_RELATIVE
bool "Specify the early stack pointer relative to the .bss section"
+ default n if ARCH_QEMU
default y if POSITION_INDEPENDENT
help
U-Boot typically uses a hard-coded value for the stack pointer
diff --git a/configs/qemu_arm64_defconfig b/configs/qemu_arm64_defconfig
index 31ea2d342fc..4450e7ced42 100644
--- a/configs/qemu_arm64_defconfig
+++ b/configs/qemu_arm64_defconfig
@@ -1,6 +1,7 @@
CONFIG_ARM=y
CONFIG_ARCH_QEMU=y
CONFIG_NR_DRAM_BANKS=1
+CONFIG_POSITION_INDEPENDENT=y
CONFIG_ENV_SIZE=0x40000
CONFIG_ENV_SECT_SIZE=0x40000
CONFIG_AHCI=y
--
2.17.5