Re: [avr-chat] HowTo split a program into several files ?

[David Kelly]

On Sep 12, 2005, at 5:55 PM, Vincent Trouilliez wrote:

> > The Makefile I sent to you started life as one of Joerg's demo
> > Makefiles. The TWI demo IIRC.
> >
> > Anyway, mine has some enhancements, yet its still simple. Just  
> > list your
> > .c files in the SRCS definition. Is currently one file per line. The
> > last character before newline is a backslash. Backslash escapes the
> > newline and continues the logical line to the next physical line.
>
> David I love you !!! :o)
>
> It worked ! I just added main.c and lcd.c in your file, selected my
> ATmega32 chip at the top of the file, and... it complained that my  
> chip
> couldn't use the "-gdwarf-2" option.  Not having the slightest clue as
> to what this options meant, I simply removed it, ran make again, and
> after a few apparently harmless warnings, it eventually coughed a few
> files !!! :-)

What I think it means is that you have an old version of avr-gcc. Or  
that dwarf-2 was not compiled into your avr-gcc. Its not a function  
of your ATmega32 vs my 64. Don't go jumping to 4.x just yet, stay  
with 3.4.x.

% avr-gcc --version
avr-gcc (GCC) 3.4.4
Copyright (C) 2004 Free Software Foundation, Inc.
This is free software; see the source for copying conditions.  There  
is NO
warranty; not even for MERCHANTABILITY or FITNESS FOR A PARTICULAR  
PURPOSE.

> The one called "object_flash.hex" caught my eye, tried downloading  
> that
> into the AVR using Avrdude and oh, magic, my program's running
> perfectly !! :o)

IIRC Dwarf-2 is a debugging extension added to elf format. AVR Studio  
needs the Dwarf-2 stuff to properly source-code debug. I normally  
load the elf file but enhanced the Makefile to generate separate .hex  
files for flash and eeprom in order to use the Atmel ISP for the  
production line.

> Only thing I miss is that your "list" file, although it does  
> contain the
> entire program (main and lcd) doesn't show the C statements.

I built my project just now without -gdwarf-2 and also did not get  
source interspersed with assembly in object.list. Upgrade/update your  
avr-gcc. With -gdwarf-2 the source and assembly appear together in  
the list file:

//
//      ee_writes( sram source, ee dest, count );
//
void
ee_writes(const void *cp, void *addr, uint16_t n)
{
    32a4:       fc 01           movw    r30, r24
        uint8_t sreg;           //  store SREG

        for( ; n ; n-- ) {
    32a6:       41 15           cp      r20, r1
    32a8:       51 05           cpc     r21, r1
    32aa:       b9 f0           breq    .+46    ; 0x32da <ee_writes 
+0x36>
                wdt_reset();
    32ac:       a8 95           wdr
                while( EECR & (1<<EEWE) )       //  wait until ready
    32ae:       e1 99           sbic    0x1c, 1 ; 28
    32b0:       fe cf           rjmp    .-4     ; 0x32ae <ee_writes 
+0xa>
                        ;
...

> Wow, what a day ! I learnt how to split my programs correctly using .c
> and .h files, and I can also use Makefiles (and I already love them,
> especially the "make clean" option ! :-), so convenient now I know it
> does actually work ! ;-)

I think you'll learn to love "make depend" more than "make clean"  :-)

--
David Kelly N4HHE, address@hidden
========================================================================
Whom computers would destroy, they must first drive mad.