Re: [avr-gcc-list] WinAVR, file XXX not found in symbol table, ignoring...

[Jurek Szczesiul]

> Unfortunately, you'll have to talk to Atmel (Torleif) about this one. 
> The email address to use is:
> avr AT atmel.com
> 

Some posts from october 2004 :

To Torleif :

**************************************
Hi Torleif !

> If you could send me an example project with both c and assembly code I will 
> probably be able to provide an answer to your question more quickly.

I've prepared a very simple project :

main.c - with main() function
intc.c - C source of ext interrupt 0 handler
ints.s - asm source of ext interrupt 1 handler
asmdat.s - asm source with an auxiliary function

It is compiled for atmega8 like this :
1. avr-gcc.exe -c -mmcu=atmega8 -x assembler-with-cpp -Wa,--gstabs  asmdat.s
2. avr-gcc.exe -c -mmcu=atmega8 -x assembler-with-cpp -Wa,--gstabs ints.s
3. avr-gcc.exe -gdwarf-2 -Os -mmcu=atmega8 -c -pipe -Wall  intc.c
4. avr-gcc.exe -gdwarf-2 -Os -mmcu=atmega8 -c -pipe -Wall   main.c
............................
5. avr-gcc.exe -mmcu=atmega8 -Wl,-Map=asmtest.map,--cref -o asmtest.elf 
asmdat.o intc.o ints.o main.o

( MinGW32 toolset 3.4.2 + 2.15 + 1.0.4 has been used on  Windows XP Pro SP2, 
but it's probably not very important ).

AvrStudio 4.10/356 + all the newest patches I've found on avrfreaks.

Simulation runs like this:
- stepping with F11 around empty loop (while...) I trigger int0 setting 
manually INTF0, after next F11 I can see int0 handler ( in intc.c ), step 
through and return to loop ( port B has a valid value 0x55 )
- then I trigger int1 setting INTF1 - asm handler is transparent for 
source-code-debugging - after F11 port B simply becomes 0xaa.

Everything works OK of course - jumps are pretty proper in disassembler window. 
However, it would be nice to look inside asm handler ( or any function ) from 
source code level ( eg. to have ints.s on separated tab and jump into it ).
Is this possible ?

Best regards
Jurek S.
 
********************************************



>From Torleif :
********************************************
Hi Jurek.

Thanks for your efforts!

AVRStudio shall be able to debug a mix of C and assembly files.
The problem is that the object file does not contain debug information that 
Studio can handle.

The stabs format is not supported by AVRStudio, so the --gstabs option to 
avr-gcc, (avr-as), will not do any good.

I have tried to add dwarf debugging information to the objectfile with the 
--gdwarf2 assembler option, but this did not make any difference in the 
asmtest.elf object file. (avr-readelf -wl did not show any asm statements)

So our problem seems to be that we are unable to put dwarf debug information 
into the object file. Once this obstacle is cleared, I think we can debug this 
mix of assembly and C.

I will try to find time to investigate this issue further.

Regards,

Torleif Sandnes
Atmel AVR Software Team
*********************************************


To Torleif  again:
*********************************************
Hi Torleif !
Thanks for answer !

> I have tried to add dwarf debugging information to the objectfile with the 
> --gdwarf2 assembler option, but this did not make any difference in the 
> asmtest.elf object file. (avr-readelf -wl did not show any asm statements)

> So our problem seems to be that we are unable to put dwarf debug information 
> into the object file. Once this obstacle is cleared, I think we can debug 
> this 
> mix of assembly and C.
> 

Now, I'm afraid it will not be a simple task :-(
I've looked into intc.s - intermediate asm file automatically generated ( -S 
option ) for intc.c module. Creating such a debug info section manually seems 
to be hopeless. IMHO some automatic tool would be the only solution for this.
However, my knowledge of debug formats is minimal. Some gcc guru ( like Joerg 
Wunsch ) is wanted here.

Best regards Jurek S.
******************************************

That's all for today.
( --gstabs was my obvious error, but Torleif tried with --gdwarf2 as well )

HTH

Best regards Jurek S.