Question

I have a Makefile like this:

baud=19200
src=dimmer
avrType=attiny13
programmerDev=/dev/ttyUSB003
programmerType=stk500v1

object:
        avr-gcc -g -DF_CPU=$(avrFreq) -Wall -Os -mmcu=$(avrType) -c -o $(src).o $(src).cpp

read:
        @for memory in calibration eeprom efuse flash fuse hfuse lfuse lock signature application apptable boot prodsig usersig; do \
                avrdude -p $(avrType) -c$(programmerType) -P$(programmerDev) -b$(baud) -v -U $$memory:r:./$(avrType).$$memory.hex:i; \
        done

Which works as intended. When I type make read several files are extracted from the microcontroller. This can take a little while because of the slow connection and data size, so I was thinking it would be nice to be able to just type make read flash, but I can’t figure out how to do that.

Of course I can make entries like read_flash, read_hfuse … but I have a feeling it can be done smarter.

I also want to be able to run a command like make read all which will execute every file in turn from the controller.

Now I am new to creating Makfile’s, so maybe I am on the wrong track all together. Please feel free to explain how it should be done.

I am on Linux.

Answer 1

If a highly GNU-specific makefile is acceptable to you (and I’d argue that it’s much better to use a portable make, such as GNU’s, than writing portable makefiles), you can implement this rather easily:

ALL = calibration eeprom efuse flash fuse hfuse lfuse lock signature \
      application apptable boot prodsig usersig

ifeq (read,$(firstword $(MAKECMDGOALS)))
  WANT := $(wordlist 2,$(words $(MAKECMDGOALS)),$(MAKECMDGOALS))
  ifneq ($(WANT),)
    $(eval $(WANT):;@:)
  endif
  UNKNOWN := $(filter-out $(ALL),$(WANT))
  ifneq ($(UNKNOWN),)
    $(error Invalid arguments: $(UNKNOWN))
  endif
endif

read-one = avrdude -p $(avrType) -c$(programmerType) -P$(programmerDev) \
        -b$(baud) -v -U $1:r:./$(avrType).$1.hex:i

.PHONY: read
read:
    $(foreach w,$(or $(WANT),$(ALL)),$(call read-one,$w) &&) :

If the first argument in the command line is “read”, this sets the WANT variable to the list of arguments after the first. It then turns those names into no-op targets and makes the read target invoke the read-one function for each name, or for $(ALL) if no name was specified.

I use variations of this quite often, for things like make print VARIABLE..., which will just print $(VARIABLE) or make help TOPIC to display information about a target.