Re: update ARM platform HALs

[Jonathan Larmour <jifl@eCosCentric.com>]

John Dallaway wrote:
> Hi Jifl
> 
> Jonathan Larmour wrote:
> 
> 
>>John Dallaway wrote:
>>
>>
>>>The eCosCentric arm-eabi pre-built toolchains do not include StrongARM
>>>multi-libs. AFAIK, users who want to build eCos for these targets will
>>>therefore need to either build their own arm-eabi-gcc or revert to
>>>CYGBLD_GLOBAL_COMMAND_PREFIX == "arm-elf" and use the older arm-elf-gcc
>>>3.2.1. Can you please let me know what the intention is here so I can
>>>mention this in the eCos 3.0 release notes?
>>
>>This was discussed before IRL, and I believe until I hear to the
>>contrary that strongarm should probably still work. It just won't be
>>perfectly optimal as it will fall back to the arm7tdmi multilib (the
>>default); but now actually looking at GCC sources, I think it may have
>>only a virtually perceptible effect even then.
> 
> 
> IIRC, Bart observed a SIGTRAP in libgcc (udivsi3?) when running up eCos
> built with arm-eabi-gcc 4.3.2 on the ipaq target. So perhaps users would
> be better off sticking with arm-elf-gcc 3.2.1 for StrongARM? I'm not
> proposing that we spend any further time investigating the problem, just
> seeking clarification as to what we should recommend to users.

Well, I've had a closer look, and indeed the prebuilt tools won't just 
work after all, because, even if thumb interworking is disabled, gcc uses 
ARMv4t insns like 'bx', which aren't available on strongarm's ARMv4.

If people want to use strongarm, they can indeed either use the older 
tools, or rebuild the current tools with strongarm multilibs added.

Of course, I don't expect anyone to be using strongarm in new designs as 
they've been discontinued.

Jifl
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