scripts/Makefile.lib: EFI: Use capsule CRT instead of ESL file

The EFI Capsule ESL file (EFI Signature List File) used for authentication
is a binary generated from the EFI Capsule public key certificate. Instead
of including it in the source repo, automatically generate it from the
certificate file during the build process.

Currently, sandbox is the only device using this, so removed its ESL file
and set the (new) CONFIG_EFI_CAPSULE_CRT_FILE config to point to its public
key certificate.

Signed-off-by: Jonathan Humphreys <j-humphreys@ti.com>

6 files changed, 27 insertions, 19 deletions

diff --git a/board/sandbox/capsule_pub_esl_good.esl b/board/sandbox/capsule_pub_esl_good.esl
deleted file mode 100644
index f8cc272309b..00000000000
--- a/board/sandbox/capsule_pub_esl_good.esl
+++ /dev/null
diff --git a/configs/sandbox_defconfig b/configs/sandbox_defconfig
index da8c1976d7b..e2db66d4a25 100644
--- a/configs/sandbox_defconfig
+++ b/configs/sandbox_defconfig
@@ -353,7 +353,7 @@ CONFIG_EFI_RUNTIME_UPDATE_CAPSULE=y
 CONFIG_EFI_CAPSULE_ON_DISK=y
 CONFIG_EFI_CAPSULE_FIRMWARE_RAW=y
 CONFIG_EFI_CAPSULE_AUTHENTICATE=y
-CONFIG_EFI_CAPSULE_ESL_FILE="board/sandbox/capsule_pub_esl_good.esl"
+CONFIG_EFI_CAPSULE_CRT_FILE="board/sandbox/capsule_pub_key_good.crt"
 CONFIG_EFI_SECURE_BOOT=y
 CONFIG_TEST_FDTDEC=y
 CONFIG_UNIT_TEST=y
diff --git a/configs/sandbox_flattree_defconfig b/configs/sandbox_flattree_defconfig
index 6bf8874e722..049a606613e 100644
--- a/configs/sandbox_flattree_defconfig
+++ b/configs/sandbox_flattree_defconfig
@@ -227,7 +227,7 @@ CONFIG_EFI_RUNTIME_UPDATE_CAPSULE=y
 CONFIG_EFI_CAPSULE_ON_DISK=y
 CONFIG_EFI_CAPSULE_FIRMWARE_FIT=y
 CONFIG_EFI_CAPSULE_AUTHENTICATE=y
-CONFIG_EFI_CAPSULE_ESL_FILE="board/sandbox/capsule_pub_esl_good.esl"
+CONFIG_EFI_CAPSULE_CRT_FILE="board/sandbox/capsule_pub_key_good.crt"
 CONFIG_UNIT_TEST=y
 CONFIG_UT_TIME=y
 CONFIG_UT_DM=y
diff --git a/doc/develop/uefi/uefi.rst b/doc/develop/uefi/uefi.rst
index 88596f312c0..d450b12bf80 100644
--- a/doc/develop/uefi/uefi.rst
+++ b/doc/develop/uefi/uefi.rst
@@ -580,10 +580,10 @@ and used by the steps highlighted below.
     }
 
 You can perform step-4 through the Kconfig symbol
-CONFIG_EFI_CAPSULE_ESL_FILE. This symbol points to the esl file
-generated in step-2. Once the symbol has been populated with the path
-to the esl file, it will automatically get embedded into the
-platform's dtb as part of U-Boot build.
+CONFIG_EFI_CAPSULE_CRT_FILE. This symbol points to the signing key
+generated in step-2. As part of U-Boot build, the ESL certificate file will
+be generated from the signing key and automatically get embedded into the
+platform's dtb.
 
 Anti-rollback Protection
 ************************
diff --git a/lib/efi_loader/Kconfig b/lib/efi_loader/Kconfig
index ee71f417147..2fb24d7af9a 100644
--- a/lib/efi_loader/Kconfig
+++ b/lib/efi_loader/Kconfig
@@ -298,13 +298,15 @@ config EFI_CAPSULE_MAX
 	  Select the max capsule index value used for capsule report
 	  variables. This value is used to create CapsuleMax variable.
 
-config EFI_CAPSULE_ESL_FILE
-	string "Path to the EFI Signature List File"
+config EFI_CAPSULE_CRT_FILE
+	string "Path to the EFI capsule public key certificate"
 	depends on EFI_CAPSULE_AUTHENTICATE
 	help
-	  Provides the path to the EFI Signature List file which will
-	  be embedded in the platform's device tree and used for
-	  capsule authentication at the time of capsule update.
+	  Provides the path to the EFI capsule public key certificate that
+	  corresponds to the capsule signing key. This certificate will be used
+	  to generate the EFI capsule ESL (signature list file) that gets
+	  embedded in the platform's device tree and used for capsule
+	  authentication at the time of capsule update.
 
 config EFI_DEVICE_PATH_TO_TEXT
 	bool "Device path to text protocol"
diff --git a/scripts/Makefile.lib b/scripts/Makefile.lib
index d3c95f3446f..f66a65d1c1f 100644
--- a/scripts/Makefile.lib
+++ b/scripts/Makefile.lib
@@ -342,21 +342,27 @@ cmd_dtc = mkdir -p $(dir ${dtc-tmp}) ; \
 		; \
 	sed "s:$(pre-tmp):$(<):" $(depfile).pre.tmp $(depfile).dtc.tmp > $(depfile)
 
+capsule_esl_input_file=$(srctree)/lib/efi_loader/capsule_esl.dtsi.in
+capsule_crt_file=$(subst $(quote),,$(CONFIG_EFI_CAPSULE_CRT_FILE))
+capsule_esl_dtsi=.capsule_esl.dtsi
+
 quiet_cmd_capsule_esl_gen = CAPSULE_ESL_GEN $@
-cmd_capsule_esl_gen = \
-	$(shell sed "s:ESL_BIN_FILE:$(capsule_esl_path):" $(capsule_esl_input_file) > $@)
+cmd_capsule_esl_gen = cert-to-efi-sig-list $< $@
 
-$(obj)/.capsule_esl.dtsi: FORCE
-ifeq ($(CONFIG_EFI_CAPSULE_ESL_FILE),"")
-	$(error "CONFIG_EFI_CAPSULE_ESL_FILE is empty, EFI capsule authentication \
+$(obj)/capsule_esl_file: $(capsule_crt_file) FORCE
+ifeq ($(CONFIG_EFI_CAPSULE_CRT_FILE),"")
+	$(error "CONFIG_EFI_CAPSULE_CRT_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=$(srctree)/lib/efi_loader/capsule_esl.dtsi.in
-capsule_esl_dtsi = .capsule_esl.dtsi
-capsule_esl_path=$(abspath $(srctree)/$(subst $(quote),,$(CONFIG_EFI_CAPSULE_ESL_FILE)))
+quiet_cmd_capsule_dtsi_gen = CAPSULE_DTSI_GEN $@
+cmd_capsule_dtsi_gen = \
+	$(shell sed "s:ESL_BIN_FILE:$(abspath $<):" $(capsule_esl_input_file) > $@)
+
+$(obj)/$(capsule_esl_dtsi): $(obj)/capsule_esl_file FORCE
+	$(call cmd,capsule_dtsi_gen)
 
 dtsi_include_list_deps := $(addprefix $(u_boot_dtsi_loc),$(subst $(quote),,$(dtsi_include_list)))