change log for rtems (2010-06-15)

Ralf Corsepius ralf.corsepius at rtems.org
Thu Jun 17 08:08:05 UTC 2010


On 06/17/2010 09:53 AM, Chris Johns wrote:
> On 16/06/10 8:40 PM, Ralf Corsepius wrote:
>>
>> => rtems_rfs_fs_size is broken. The uint64_t cast is dysfunctional.
>>
>
> I attach a patch for HEAD and 4.10. Is this ok to apply ?
Now, I am confused.

After having applied further changes, I reverted my change ... to be checked

>>
>> 64bit filesystems are
>> * non-applicable on machines without 64bit support.
>
> I was referring to support for 64bit sized file systems and 64bit file 
> offsets not the target characteristics.
Well, in the current rfs implementation in RTEMS, these are not clearly 
separated.

To put it less theoretically: rfs will not be usable if a 
target/toolchain doesn't support 64bit types and will be ineffective 
(slow) to use on targets which don't have 64bit instruction sets (IIRC, 
gcc emulates 64bit on some targets).

>> * ineffective on many 16/32bit cpus.
>> * ineffective in applications when filesystem sizes are guaranteed to be
>> small.
>> * a waste of resources on small systems.
>
> I will leave this to our user to decide.
>
> The RFS is not big in terms of code. RAM usage for buffering and 
> caching plus newlib buffers would be hard on RAM challenged hardware.
This used to be different.

Ralf




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