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

[Vincent Trouilliez]

On Mon, 2005-09-12 at 19:33 +0200, Vincent Trouilliez wrote:
> > Or you can tell  the compiler to directly compile and link seperate source 
> > files by just 
> > feeding them all into gcc at once (gcc -o foo main.c foo.c morefiles.c ...) 

Till, I am getting there: I added a couple includes to lcd.h and now gcc
-o foo main.c lcd.c doesn't complain anymore :-)
Thanks for your further comments on includes which I just read.


Okay I am almost there. Problem : I am hardly confident with the ins and
out of gcc and all related tools. So so far I have used all the command
stated in the 'demo' project in avr-libc, and put them together in a
script, so that everything is done at once and all the files are
generated automatically :

avr-gcc -g -Os -mmcu=atmega32 -c demo.c
avr-gcc -g -mmcu=atmega32 -Wl,-Map,demo.map -o demo.elf demo.o
avr-objdump -h -S demo.elf > demo.lst
avr-objcopy -j .text -j .data -O ihex "$1".elf "$1".hex

This worked perectly so far, and am now therefore trying to accomodate
this script for use with multiple files. So my best attempt is :

avr-gcc -g -Os -mmcu=atmega32 -c  main.c lcd.c
avr-gcc -g -mmcu=atmega32 -Wl,-Map, main.map -o main.elf main.o lcd.o
avr-objdump -h -S main.elf > main.lst
avr-objcopy -j .text -j .data -O ihex main.elf main.hex

My understanding is : 

1) gcc -c main.c lcd.c will compile the two .c files and generate
main.o and lcd.o.

2) Then gcc -o is used to link a number of .o files into a single .elf
executable file

3) This .elf file is then used by avr-objdump and avr-objcopy to
generate a number of other files, among which we find the .hex that will
actually make it into the AVR chip.

That's the best/clearest reasoning I can come up with so far, I hope
it's not too crap :-/

Problem : phase 1) seems okay : main.o and lcd.o are created, but phase
2) fails : no .elf file is created :o(  Of course phase 3) fails too as
it has no .elf file to work with.


So I guess I got the syntax of the gcc -o phase, wrong...right ?

Please help me correct this line... I feel I am a split hair from
success !! :-)


Regards,


--
Vince