Allow to pass extra arguments to bin file creation

[BenBE]

When building multi-part binary bundles it's necessary to inflate the generated .bin file for some targets (e.g. when creating a bootloader). Currently there's no direct option to pass additional arguments for the mcu_elf2bin such that additional arguments like --pad-to 0x8008000 --gap-fill 0xff can be passed.

Also it'd be nice to have the various target files available as TARGET_PROPERTIES so they can be referenced in generator expressions for dependent targets:

add_custom_command(
    OUTPUT bundle.bin
    COMMAND
    cat
    "$<TARGET_PROPERTY:bootloader,TARGET_FILE_BIN>"
    "$<TARGET_PROPERTY:firmware,TARGET_FILE_BIN>"
    > "${CMAKE_CURRENT_BINARY_DIR}/bundle.bin"
    DEPENDS bootloader firmware
    COMMENT "Generating firmware bundle"
)

[patrislav1]

I believe application-specific stuff like inflating a bootloader can be easily handled by the application itself, so IMHO it's not necessary to add more complexity here. See below for a rough example how I did it in a similar project.

Agree about TARGET_FILE_BIN though - would you be willing to write a PR?

add_executable(application ....)
add_executable(bootloader ....)

...

add_custom_target(bootloader_padded
    COMMAND "${CMAKE_OBJCOPY}" -O binary --pad-to 0x00010000 --gap-fill 0xff
    bootloader.elf
    bootloader_padded.bin
    BYPRODUCTS bootloader_padded.bin
    COMMENT "Generating padded bootloader file"
    DEPENDS bootloader
)

add_custom_target(firmware_bundle ALL
    COMMAND cat "bootloader_padded.bin" "application.bin" > "application_bundle.bin"
    DEPENDS bootloader_padded
    DEPENDS application
    BYPRODUCTS "application_bundle.bin"
    COMMENT "Generating bundle.bin"
)

[BenBE]

ACK, this can be easily solved by an extra custom target. Yet I think the cleaner solution would be just one arg IMG_BIN_FLAGS defaulting to "" which is passed to those img util functions. Otherwise you'd effectively extract the binary image twice.

Will take a look at doing a PR for defining custom target properties for the target files.

[patrislav1]

Ok, I had another look and the added complexity to cubemx.cmake seems not as bad. See https://github.com/patrislav1/cubemx.cmake/commit/51b7e1e44b7b79f8e38688b7116a3d7a66bf4bfe