[nrf noup] sysbuild: Support for ED25519 with SHA512 and PureEdDSA

The commit adds imgtool parameters that allow to sign image with
SHA512, for ED25519, or use PureEdDSA variant, where signature
is calculated over entire image rather than SHA of that image.

Signed-off-by: Dominik Ermel <[email protected]>

Author: de-nordic

share/sysbuild/image_configurations/MAIN_image_default.cmake

@@ -37,4 +37,16 @@ if(SB_CONFIG_BOOTLOADER_MCUBOOT)
   elseif(SB_CONFIG_MCUBOOT_MODE_FIRMWARE_UPDATER)
     set_config_bool(${ZCMAKE_APPLICATION} CONFIG_MCUBOOT_BOOTLOADER_MODE_FIRMWARE_UPDATER y)
   endif()
+
+  set(imgtool_extra_args "${CONFIG_MCUBOOT_EXTRA_IMGTOOL_ARGS}")
+  if(SB_CONFIG_BOOT_SIGNATURE_TYPE_ED25519)
+    if(SB_CONFIG_BOOT_SIGNATURE_TYPE_PURE)
+      string(APPEND imgtool_extra_args " --pure")
+    else()
+      string(APPEND imgtool_extra_args " --sha 512")
+    endif()
+  endif()
+
+  set_config_string(${ZCMAKE_APPLICATION} CONFIG_MCUBOOT_EXTRA_IMGTOOL_ARGS "${imgtool_extra_args}")
+
 endif()