On Wed, Jan 18, 2012 at 4:15 AM, Florian Fainelli <[email protected]> wrote:
> Hello Jon,
>
>
> On 01/18/12 03:19, [email protected] wrote:
>>
>> I think I finally found the problem with getting Cairo to work on ARM.
>> What I thought was a problem with an index in the Truetype file
>> actually turned out to be a code generation flaw in the 4.5-linaro
>> compiler. The flaw was in libpixman which is a supporting library for
>> cairo. Compiling libpixman with -O0 made everything work. O1,O2,O3,Os
>> all failed. The flaw was causing random writes that corrupted memory.
>> I identified the subroutine with the code generation problem but I
>> didn't debug the assembly code.
>>
>> While I was working on this bug OpenWRT was updated to the 2012-1
>> release of 4.6 gcc-linaro. That release fixed the compiler bug that
>> was causing openssl not to build. And guess what, libpixman now works
>> at all optimization levels on that compiler.
>
>
> Thank you for your detailed analysis and letting us know about your progress
> and findings. If that may interest gcc developpers you might want to report
> the libxpixman bad code generation to their bugtracker in case they plan on
> releasing an updated gcc-4.5 release.

I didn't track things down further since debugging is too painful
without hardware watchpoints working. Some of these issues with gdb
need to get fixed...

> Any ideas why the target ARM gdb doesn't work?
>
> run gdb ...
> This GDB was configured as "arm-openwrt-linux"...
> I'm sorry, Dave, I can't do that.  Symbol format `elf32-littlearm' unknown.
>
> gdbremote works, but it doesn't support hardware breakpoints until the
> 7.x series and we're at 6.8. 7.2 won't build because it complains the
> C run-time is too old.
>
> Target gdb should support hardware breakpoints if I can get it running.
>


>
>
>>
>> So I hope my problems are gone for now. I have a dozen test programs
>> and they are all running. I'm hoping the problem is truly fixed and
>> hasn't just moved around again.
>>
>> Once I'm confident with stability I'll prepare patches moving cairo,
>> pixman, freetype, liberation up to more recent versions. Plus I'll
>> package the luaCairo wrapper. With those additions you'll be able to
>> draw pretty pictures on screens with lua scripts.
>>
>
> Allright, thanks!
> --
> Florian



-- 
Jon Smirl
[email protected]
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