[maemo-developers] Toolchain upgrade? (Was: Instructions cache flush on ARM)

[From: Riku Voipio]

Siarhei Siamashka wrote:
>> Hm.  The toolchain might not be built with -pg support.
>> As to using gprof, that produces fairly unreliable results.
>> I'd recommend building Oprofile kernel and latest oprofile
>> user-space tools.
>>     
>
> Maybe Oprofile is good, but  gprof is better than nothing and does not require
> recompiling kernel.
>
>   
OTOH you don't need to recompile apps with -pg to profile with oprofile.
One needs to "just" recompile the kernel once.
> Well, I'm worried not about how to workaround ICE but about the overall
> quality of the compiler. I wonder how many compiler related bugs are lurking
> in maemo software but are not caught yet? 
>   
Me too..
> Did anybody try installing newer toolchains in scratchbox and use them with
> maemo SDK? I just don't have much free time for these experiments and 
> don't want to break my installation of scratchbox which works now (more or
> less acceptable)
>   
No reason why it shouldn't work, one just needs to be sure the 
glibc/libstd++
built is matching enough. I tried the newer codesourcery toolchain (based
on gcc 4.1, and it mostly worked, except for apps using certain depreciated
syscalls. (i've forgotten already which ones).

http://www.scratchbox.org/wiki/ForeignToolchains

> Enabling unaligned memory support will make life much easier for developers
> unfamiliar with ARM platform. The number of applications for N800 should 
> grow up, as less newbee developers will be turned away frustrated by the
> alignment bugs they have never heared about before.
>   
Alignment issues exist for other risc processors as well (hppa, alpha, 
ia64),
so most Linux programs to be ported to n800 should already be fixed.  Also,
who says all maemo products will be arm11 based? arm9 isn't going to
disappear overnight, especially it seems xscales will continue to evolve as
arm9-based.

This is of course just objecting for the sake of it:) I don't have
anything against enabling unaligned memory support, so tested patches
would be appreciated ;)