Get FLASH_FILE and ELFFILE from command line instead of environment variable.
The documentation was claiming ELFFILE was given as a command line argument
already, but is was not.
Get BINFILE and ELFFILE from command line instead of environment variable.
Rename 'HEXFILE' to 'BINFILE' in the script as the binary file is used.
The documentation was already talking about 'BINFILE' but 'BINFILE'
was never exported by the build system and it was using 'HEXFILE' in the
implementation.
Handle that `IMAGE_OFFSET` can be set to something that contain spaces.
With 'IMAGE_OFFSET=$$((0x1000 + 0x1000))' we had in the command line when doing
'flash'
--offset $((0x1000 --offset + --offset 0x1000))
With the change we correctly have
--offset $((0x1000 + 0x1000))
Allow flashing with an offset in ROM from the rom base address.
It reuses `IMAGE_OFFSET` configuration variable name from `openocd.sh`.
This will allow flashing multiple images with different flash operations.
Attempt to decouple board configuration from debugger interface
configuration by specifying the DEBUG_IFACE variable for the debug
hardware interface to use.
