Re: avr-gcc

[Ricardo Wurmus]

Ricardo Wurmus <address@hidden> writes:

> I’ve been wanting to use microscheme to do fun things with my AVR
> microcontrollers.  Sadly, I haven’t been able to make the combination of
> microscheme, avrdude, and avr-gcc work.

[...]

> There are multiple copies of “libm.a” and “libc.a” and there’s a
> “crtm328p.o” as well somewhere below the “avr/lib/” directory in the
> output of the avr-libc package.  Even after adding these paths to
> LIBRARY_PATH, however, I cannot seem to fix the linker errors above.
> Then I realised that LIBRARY_PATH only works for native compilers, and
> that I would need to pass flags to the compiler (“-L”, maybe?).
>
> But this all seems very wrong.  How can we fix this elegantly?  Does
> microscheme’s call to avr-gcc need to be patched to “-L” the avr-libc
> path?  Or does avr-gcc need fixing?  Or something else entirely?

I first looked at how to fix this inelegantly.  “crtm328p.o” cannot be
found no matter what I did, so I copied it from the store to the current
directory:

~~~~~~~~~~~~
address@hidden ~ $ cp 
/gnu/store/b8p4kkhcly7k5klnrzxmql35d541xhgq-avr-libc-1.8.1/avr/lib/avr5/crtm328p.o
 .
~~~~~~~~~~~~

Then I discovered microscheme’s “-w” flag which lets me paste stuff to
the end of the call to avr-gcc.  I abuse it to add the avr-libc lib
directory containing “libc.a” and “libm.a”:

~~~~~~~~~~~~
address@hidden ~ $ microscheme -a -u -m UNO -d /dev/bus/usb/006/004 -w 
"-L/gnu/store/b8p4kkhcly7k5klnrzxmql35d541xhgq-avr-libc-1.8.1/avr/lib/avr5/" 
microscheme/examples/BLINK.ms 
Microscheme 0.9.2, (C) Ryan Suchocki
>> Treeshaker: After 4 rounds: 87 globals purged! 22 bytes will be reserved.
>> 18 lines compiled OK
>> Assembling...
>> Uploading...
avrdude: ser_open(): can't set attributes for device "/dev/bus/usb/006/004": 
Inappropriate ioctl for device

avrdude done.  Thank you.

>> Warning: Command may have failed. (Exit code 256)
>> Finished.
~~~~~~~~~~~~

Yes!  It actually assembled the example!

(Uploading fails, of course, because I shouldn’t try to write to a raw
USB device.  For some reason the AVRISPmkII USB programming device
doesn’t appear as a regular serial device, so some more work is needed
here.)

So, back to the original question: how could we fix this in an elegant
manner?  This hack will last me for some tests, but it feels really
icky.

~~ Ricardo