[Buildroot] [PATCH v2 1/1] boot/arm-trusted-firmware: override BL31 environment variable error

[Neal Frager]

When building the arm-trusted-firmware, if the host environment has a value
configured in the BL31 variable such as the following:

export BL31=/tmp/bl31.elf

This will cause the build of the bl31.elf to be skipped leading to the
following build error:

make[1]: Nothing to be done for 'bl31'.
And then:
readelf: Error: './output/build/arm-trusted-firmware-custom/build/versal/release/bl31/bl31.elf': No such file

To fix this, clear the BL31 variable in the MAKE_OPTS, so that building the
arm-trusted-firmware will build regardless of the host environment.

Signed-off-by: Neal Frager <neal.frager at amd.com>
---
V1->V2:
- correct file path in commit subject
---
 boot/arm-trusted-firmware/arm-trusted-firmware.mk | 1 +
 1 file changed, 1 insertion(+)

diff --git a/boot/arm-trusted-firmware/arm-trusted-firmware.mk b/boot/arm-trusted-firmware/arm-trusted-firmware.mk
index dca16d3960..021ab5c092 100644
--- a/boot/arm-trusted-firmware/arm-trusted-firmware.mk
+++ b/boot/arm-trusted-firmware/arm-trusted-firmware.mk
@@ -162,6 +162,7 @@ endif
 
 ifeq ($(BR2_TARGET_ARM_TRUSTED_FIRMWARE_BL31),y)
 ARM_TRUSTED_FIRMWARE_MAKE_TARGETS += bl31
+ARM_TRUSTED_FIRMWARE_MAKE_OPTS += BL31=
 endif
 
 ifeq ($(BR2_TARGET_ARM_TRUSTED_FIRMWARE_BL31_UBOOT),y)
-- 
2.25.1