Re: [avr-gcc-list] very simple program

[Timothy Smith]

David Kelly wrote:

> On Oct 2, 2005, at 7:21 AM, Timothy Smith wrote:
>
> > i'm learning the in's and out's of microcontroller programming, but  
> > i've run into a really fundamental problem.  i get the following  
> > error when i attempt to use _BV to shift a shit and set port b pin  0 
> > to output
> >
> > 4: undefined reference to `__stack'
> >
> > and here is my code
> >
> > #include <avr/io.h>
> >
> > int
> > main(void){
> >      while (1) {
> >        DDRB = _BV(PB0);
> >    };
> > }
>
>
> Yeah, well what else are you doing? What CPU? How are you specifying  
> the CPU to the compiler? Who is complaining about __stack? My guess  
> is that its the linker not the compiler and it has something to do  
> with your CPU selection or failure to specify to both compiler and  
> linker.
>
> Also use of _BV(PB0) is discouraged as its nothing more than (1<<PB0)  
> and for most the shift is actually easier to read and understand.
>
> --

my apologes for not giving this to start with

%avr-gcc -g -mmcu=atmega32 -Os -c BarGimp.c
%avr-gcc -g   -o BarGimp.out BarGimp.o
BarGimp.o: In function `main':
Projects/BarGimp/BarGimp.c:4: undefined reference to `__stack'
Projects/BarGimp/BarGimp.c:4: undefined reference to `__stack'

and i was not aware use of  _BV() is discouraged. it seems actually be
encouraged in the avr-libc docs?

and now that i have looked at it in this email i see the problem.
-mmcuatmega32. works now

also i might like to add that i want to set port b to output and set it
high so that it lights up and led (later it will open a solenoid value)