modules: trusted-firmware-m: Allow application to use qcbor TF-M

QCBOR cannot be shipped with Zephyr.
Allow the application to supply their own copy of QCBOR or let the TF-M
build system automatically download this dependency.

Signed-off-by: Joakim Andersson <[email protected]>

Author: joerchan

modules/trusted-firmware-m/CMakeLists.txt

@@ -238,7 +238,7 @@ if (CONFIG_BUILD_WITH_TFM)
     message(FATAL_ERROR "Unsupported ZEPHYR_TOOLCHAIN_VARIANT: ${ZEPHYR_TOOLCHAIN_VARIANT}")
   endif()
 
-  if (CONFIG_TFM_PARTITION_INITIAL_ATTESTATION)
+  if (CONFIG_TFM_PARTITION_INITIAL_ATTESTATION AND CONFIG_TFM_QCBOR_PATH STREQUAL "")
     # TODO: Remove this when QCBOR licensing issues w/t_cose have been resolved,
     # or only allow it when 'QCBOR_PATH' is set to a local path where QCBOR has
     # been manually downloaded by the user before starting the build.
@@ -248,7 +248,7 @@ if (CONFIG_BUILD_WITH_TFM)
       )
   endif()
 
-  if (CONFIG_TFM_PSA_TEST_INITIAL_ATTESTATION)
+  if (CONFIG_TFM_PSA_TEST_INITIAL_ATTESTATION AND CONFIG_TFM_QCBOR_PATH STREQUAL "")
     # TODO: Remove this when QCBOR licensing issues w/t_cose have been resolved,
     # or only allow it when 'QCBOR_PATH' is set to a local path where QCBOR has
     # been manually downloaded by the user before starting the build.
@@ -258,6 +258,14 @@ if (CONFIG_BUILD_WITH_TFM)
       )
   endif()
 
+  if (CONFIG_TFM_QCBOR_PATH STREQUAL "DOWNLOAD")
+    # Change CMake cache type to string to avoid QCBOR_PATH=/absolute/path/DOWNLOAD being set.
+    set(QCBOR_PATH_TYPE ":STRING")
+  endif()
+  # Always set QCBOR_PATH, this will make sure that we don't automatically download this
+  # dependency in the TF-M build system and it will fail when set to an invalid value.
+  list(APPEND TFM_CMAKE_ARGS -DQCBOR_PATH${QCBOR_PATH_TYPE}=${CONFIG_TFM_QCBOR_PATH})
+
   if(CONFIG_BOARD_LPCXPRESSO55S69_CPU0)
     # Supply path to NXP HAL sources used for TF-M build
     set(TFM_PLATFORM_NXP_HAL_FILE_PATH ${ZEPHYR_TRUSTED_FIRMWARE_M_MODULE_DIR}/platform/ext/target/nxp/)

modules/trusted-firmware-m/Kconfig.tfm

@@ -280,6 +280,17 @@ config TFM_MCUBOOT_PATH_DOWNLOAD
 
 endchoice
 
+config TFM_QCBOR_PATH
+	string
+	prompt "Path to QCBOR or DOWNLOAD to fetch automatically"
+	default ""
+	help
+	  Path to QCBOR for TF-M builds. Due to a license issue with this
+	  library Zephyr does not ship with this library.
+	  If the application wishes to still use this library they can point
+	  to their own checkout of this library, or set to DOWNLOAD to allow
+	  TF-M build system to automatically download this.
+
 config TFM_MCUBOOT_DATA_SHARING
 	bool "Share app-specific data between TF-M and MCUBoot"
 	help