[avr-gcc-list] Re: Patch: avrtest elf reader

[Paulo Marques]

Tristan Gingold wrote:
> Hi,

Hi,

> I don't know if this is the right list to speak about avrtest or if 
> patches can be sent by mails.  If not,
> please tell me the right way.

Since avrtest was born mostly to run gcc's testsuite, I guess this is 
the best mailing list for it.

> We (=AdaCore) have been using avrtest for a while, using the first 
> posted version.  We have improved its
> speed and feature.  In the same time, avrtest had had a repository and 
> has been improved (predecoding).
>
> I am now trying to do a local merge.

Great!

> One of our improvement is direct support of ELF files.  This avoids to 
> launch avr-objcopy and also
> directly load the SRAM. 

I have been wanting to do this for a while now, and I must say that the 
code looks very similar to something I would have done myself. So, good 
work! :)

The only thing I think needs to be changed is the way the program aborts 
on error. The gcc testsuite requires the program to print either "EXIT", 
"ABORTED" or "TIMEOUT" to give a PASS / FAIL / etc. result to the test.

So, maybe changing the lines that simply "return -1" in the "load_elf" 
function to 'leave(EXIT_STATUS_ABORTED, "...")' would be enough. For 
instance, change:

+         if (addr + memsz > MAX_FLASH_SIZE)
+              return -1;

to:

+         if (addr + memsz > MAX_FLASH_SIZE)
+              leave(EXIT_STATUS_ABORTED, "program too big to fit in flash");

This would ensure that the testsuite would correctly FAIL this test, and 
the user would quickly understand why.

> This second feature allows to use a strip down version of crt1 that doesn't
> initialize the SRAM.

The only downside of this, is that if we introduce a bug in the "real" 
crt1, the testsuite might not catch it, because the memory is being 
"magically" initialized to the correct values. Maybe change this to a 
command line option?

> Comments are welcome.

All in all, good work :)

This also opens the way for reading the symbols directly from the elf 
file. This would allow avrtest to have symbolic breakpoints and better 
address <-> name translations in the logged version to make it easier to 
follow code execution.

--
Paulo Marques
Software Development Department - Grupo PIE, S.A.
Phone: +351 252 290600, Fax: +351 252 290601
Web: www.grupopie.com

"All generalizations are false."