Re: [avr-gcc-list] Unable to link using libm.a and libc.a

[Georg-Johann Lay]

Sean schrieb:
> I've been attempting to compile and link an Ada programme for the 
> Arduino.
>
> I have managed to get a simple programme compiled linked and running 
> on an AtMega328p board.  But when I start to use some of the more 
> complex functions I obviously had to start using avrlibc.
>
> I've down loaded and built avrlibc and I have then attempted to link 
> my programme.  But no matter how I try to tell the compiler/linker to
> use libc or libm I keep getting link issues:
>
> avr-gnatbind --RTS=C:\GNAT\2012\lib\gcc\avr\4.5.4\rts-zfp -nostdlib 
> -I- -x C:\Arduino\Arduino_Ada\BMP085\obj\main.ali
>
> avr-gnatlink C:\Arduino\Arduino_Ada\BMP085\obj\main.ali 
> C:\Arduino\Arduino_Ada\BMP085\\obj\crtm328p._o -nostdlib -lgcc -lc 
> -lm -mavr5 -Tdata=0x00800200 -mmcu=avr5 -g -nostdlib 
> C:\avr-ada-1.2.0_bin\avr\onewire\lib\libonewire.a 
> C:\avr-ada-1.2.0_bin\avr\debug\lib\libdebug.a 
> C:\avr-ada-1.2.0_bin\avr\crc

Why are you -nostdlib? The missing functions below are standard 
functions from libc / libgcc.


> [...] undefined reference to `memcmp'
> [...] undefined reference to `itoa'
> [...] undefined reference to `__udivmodqi4'
> [...] undefined reference to `__udivmodhi4'
> [...] many more

Also make sure that the libraries are fitting the compiler version, see 
the 4.7 release notes.

http://gcc.gnu.org/gcc-4.7/changes.html

Johann