[avr-libc-dev] AT90USB82 arch 'avr35' to gcc but 'avr5' to avr-libc

[Tod E. Kurt]

Hi,

I may have found a problem with how avr-libc treats the AT90USB82  
chips, but I'd like some other eyes in case I'm doing something  
wrong.  I'm just starting to play around with the AT90USB82 and  
rebuilt my avr-gcc toolchain to incorporate the latest patches for  
the latest devices.

In patching gcc (or really, seeing what updates gcc-4.2.3 had), the  
arch for AT90USB82 is listed as "ARCH_AVR35", but when configuring  
avr-libc, I see the following scroll by:
  config.status: creating avr/lib/avr5/at90usb82/Makefile

It seems that avr-libc still thinks this chip is arch "avr5", which  
is echoed in the listing on this page:
  http://www.nongnu.org/avr-libc/user-manual/using_tools.html

Lightly editing the 'demo' project to compile for AT90USB82 confirms  
this, as it fails when linking:

% make
avr-gcc -g -Wall -O2 -mmcu=at90usb82    -c -o demo.o demo.c
avr-gcc -g -Wall -O2 -mmcu=at90usb82  -Wl,-Map,demo.map -o demo.elf  
demo.o
/usr/local/avrtod/lib/gcc/avr/4.2.3/../../../../avr/bin/ld:  
crtusb82.o: No such file: No such file or directory
make: *** [demo.elf] Error

I found I can temporarily get it to link by doing this hack:
% cd $PREFIX/avr/lib
% ln -s avr5 avr35

% make
avr-gcc -g -Wall -O2 -mmcu=at90usb82  -Wl,-Map,demo.map -o demo.elf  
demo.o
avr-objdump -h -S demo.elf > demo.lst
[... and so on ...]

but I've not tried the resulting hex file yet to see if it would work.

I see a lot of movement in the patches around this chip so maybe I  
missed a patch, but I can't find what I missed if I did.  Help?

Thanks,
-=tod

---
Tod E. Kurt
address@hidden
http://todbot.com/blog/