cmake: build mcuboot using multi image build

Leverage multi image functionality to allow mcuboot
being built from zephyr app build dir.

Signed-off-by: Sebastian Bøe <[email protected]>
Signed-off-by: Håkon Øye Amundsen <[email protected]>

CMakeLists.txt

@@ -1339,6 +1339,7 @@ list(APPEND
   ${extra_post_build_commands}
   )
 
+
 add_custom_command(
   TARGET ${logical_target_for_zephyr_elf}
   POST_BUILD

subsys/CMakeLists.txt

@@ -13,6 +13,7 @@ add_subdirectory_ifdef(CONFIG_NET_BUF              net)
 add_subdirectory_ifdef(CONFIG_USB                  usb)
 add_subdirectory(random)
 add_subdirectory(storage)
+add_subdirectory(boot)
 add_subdirectory_ifdef(CONFIG_SETTINGS             settings)
 add_subdirectory(fb)
 add_subdirectory(power)

subsys/Kconfig

@@ -23,6 +23,8 @@ source "subsys/mgmt/Kconfig"
 
 source "subsys/net/Kconfig"
 
+source "subsys/boot/Kconfig"
+
 source "subsys/shell/Kconfig"
 
 source "subsys/usb/Kconfig"

subsys/boot/CMakeLists.txt

@@ -0,0 +1 @@
+add_subdirectory_ifdef(CONFIG_BOOTLOADER_MCUBOOT mcuboot)

subsys/boot/Kconfig

@@ -0,0 +1 @@
+rsource "mcuboot/Kconfig"

subsys/boot/mcuboot/CMakeLists.txt

@@ -0,0 +1,36 @@
+# Build a second bootloader image
+
+# TODO: Make configurable like OT until west is supported.
+set(MCUBOOT_BASE "${ZEPHYR_BASE}/../mcuboot")
+assert_exists(MCUBOOT_BASE)
+
+zephyr_add_executable(mcuboot)
+add_subdirectory("${MCUBOOT_BASE}/boot/zephyr" ${CMAKE_CURRENT_BINARY_DIR}/mcuboot)
+
+# TODO: Assert that the bootloader and image use the same key.
+
+set(SIGNED_IMAGE signed.hex)
+
+set_property(GLOBAL APPEND PROPERTY
+  extra_post_build_commands
+  COMMAND
+  ${PYTHON_EXECUTABLE}
+  ${MCUBOOT_BASE}/scripts/imgtool.py
+  sign
+  --key ${MCUBOOT_BASE}/${CONFIG_BOOT_SIGNATURE_KEY_FILE}
+  --header-size ${CONFIG_TEXT_SECTION_OFFSET}
+  --align 8           # TODO: Configurable?
+  --version 1.0       # TODO: Configurable?
+  --slot-size 0x32000 # TODO: Configurable?
+  ${KERNEL_HEX_NAME}  # TODO: Enforce that this will be present through Kconfig
+  ${SIGNED_IMAGE}
+  )
+
+set_property(GLOBAL APPEND PROPERTY
+  HEX_FILES_TO_MERGE
+  ${SIGNED_IMAGE}
+  )
+set_property(GLOBAL APPEND PROPERTY
+  HEX_FILES_TO_MERGE_TARGET
+  ${logical_target_for_zephyr_elf}
+  )

subsys/boot/mcuboot/Kconfig

@@ -0,0 +1,19 @@
+if BOOTLOADER_MCUBOOT
+
+config MCUBOOT_CMAKELISTS_DIR
+	string "Path to the directory of the MCUBoot CMakeLists.txt file"
+	default "$MCUBOOT_BASE/boot/zephyr/"
+
+endif # BOOTLOADER_MCUBOOT
+
+if MCUBOOT || BOOTLOADER_MCUBOOT
+# TODO: Support sharing Kconfig configuration between images
+config BOOT_SIGNATURE_KEY_FILE
+	string "PEM key file"
+	default "root-rsa-2048.pem"
+	help
+	  The key file will be parsed by imgtool's getpub command and a .c source
+	  with the public key information will be written in a format expected by
+	  MCUboot.
+
+endif # MCUBOOT || BOOTLOADER_MCUBOOT