Why does make hello.prog use iceprog after running make ARTY.firmware_config?

[JamesTimothyMeech]

In the Makefile iceprog used to program the arty when running make hello.prog after running make ARTY.firmware_config

we get this:

init..
cdone: high
reset..
cdone: high
Extended Device String Length is 0xFF, this is likely a read error. Ignoring...
flash ID: 0xFF 0xFF 0xFF 0xFF
file size: 13872
erase 64kB sector at 0x020000..

because this snippet from the makefile uses iceprog

# Sends the generated executable in flat binary form to SPI flash
%.prog: %.spiflash.bin
        iceprog -o 128k $<

Am I right in thinking that iceprog is the wrong tool for the job here?

[JamesTimothyMeech]

It seems that the best way to load programs onto FemtoRV is to follow the instructions in the LiteX tutorials in this repo