RTEMS 4.7.99.2 Available -- PowerPC/virtex feedback

Joel Sherrill joel.sherrill at oarcorp.com
Fri Aug 10 15:04:12 UTC 2007


Keith Robertson wrote:
> Joel Sherrill wrote:
>> Robert S. Grimes wrote:
>>> gregory.menke at gsfc.nasa.gov wrote:
>>>  
>>>> You'll have to apply -msoft-float to more than the RTEMS kernel, 
>>>> newlib
>>>> (being part of the toolchain) needed to be compiled with it as well.
>>>>       
>>> Does this mean rebuilding gcc?  Or can newlib be built separately?
>>>
>>> I assume I'll need to reconfigure gcc, right?  What switch to I add 
>>> to the configure command?
>>>   
>> If you are using the RTEMS RPMs or standard configure
>> command, then you have a lot of multilib variants.
>>
>> GCC has some differences for 403, 405, and 405fp.
>> Is the virtex CPU really a 403 like the CPU_CFLAGS indicates?
>>
>> This is the difference from gcc's viewpoint:
>>
>>     = {{"401", PROCESSOR_PPC403, POWERPC_BASE_MASK | MASK_SOFT_FLOAT},
>>          {"403", PROCESSOR_PPC403,
>>           POWERPC_BASE_MASK | MASK_SOFT_FLOAT | MASK_STRICT_ALIGN},
>>          {"405", PROCESSOR_PPC405,
>>           POWERPC_BASE_MASK | MASK_SOFT_FLOAT | MASK_MULHW | 
>> MASK_DLMZB},
>>          {"405fp", PROCESSOR_PPC405,
>>           POWERPC_BASE_MASK | MASK_MULHW | MASK_DLMZB},
>>          {"440", PROCESSOR_PPC440,
>>           POWERPC_BASE_MASK | MASK_SOFT_FLOAT | MASK_MULHW | 
>> MASK_DLMZB},
>>          {"440fp", PROCESSOR_PPC440,
>
> The xilinx virtex 4fx is a ppc405 with no floating point unit.  It is 
> definitely not a ppc403.
>
Then the custom file needs to change to reflect that and Robert needs
a fresh RTEMS compile with the new CPU flag to try that. :)

For the libraries, the t-rtems says:

MULTILIB_MATCHES        += mcpu?403=mcpu?405

Is this OK?  I shudder at the thought of needing another pair of PowerPC
multilib's to account for the 405 and 405fp. :(

--joel
> Cheers.
>
> Keith




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