[PATCH] scripts/Makefile.lib: print error when no public key is specified

[Masahisa Kojima]

The current build system embeds the EFI Signature List(ESL)
into the dtb to be used in the EFI capsule authentication.
This ESL file is specified through the CONFIG_EFI_CAPSULE_ESL_FILE
Kconfig option. If CONFIG_EFI_CAPSULE_ESL_FILE is not specified,
U-boot build ends up with failure but the cause of failure is not
easily understandable. Current error message is as follows.

FATAL ERROR: Error reading file into data: Is a directoryCheck /home/ubuntu/src/ledge/u-boot/arch/arm/dts/.synquacer-sc2a11-developerbox.dtb.pre.tmp for errors
make[2]: *** [scripts/Makefile.lib:355: arch/arm/dts/synquacer-sc2a11-developerbox.dtb] Error 1
make[1]: *** [dts/Makefile:44: arch-dtbs] Error 2
make: *** [Makefile:1165: dts/dt.dtb] Error 2
make: *** Waiting for unfinished jobs....

This commit shows the error message that CONFIG_EFI_CAPSULE_ESL_FILE
must be specified when the EFI capsule authentication is enabled, then
terminate the build with error.

Signed-off-by: Masahisa Kojima <masahisa.kojima at linaro.org>
---
 scripts/Makefile.lib | 5 +++++
 1 file changed, 5 insertions(+)

diff --git a/scripts/Makefile.lib b/scripts/Makefile.lib
index 8dc6ec82cd..16bbc277a9 100644
--- a/scripts/Makefile.lib
+++ b/scripts/Makefile.lib
@@ -339,7 +339,12 @@ cmd_capsule_esl_gen = \
 	$(shell sed "s:ESL_BIN_FILE:$(capsule_esl_path):" $(capsule_esl_input_file) > $@)
 
 $(obj)/.capsule_esl.dtsi: FORCE
+ifeq ($(CONFIG_EFI_CAPSULE_ESL_FILE),"")
+	$(error "CONFIG_EFI_CAPSULE_ESL_FILE is empty, EFI capsule authentication \
+	public key must be specified when CONFIG_EFI_CAPSULE_AUTHENTICATE is enabled")
+else
 	$(call cmd_capsule_esl_gen)
+endif
 
 capsule_esl_input_file=$(srctree)/lib/efi_loader/capsule_esl.dtsi.in
 capsule_esl_dtsi = .capsule_esl.dtsi
-- 
2.34.1