[rtems-users] Re: tar filesystem

[Joel Sherrill <joel@OARcorp.com>]

Till Straumann wrote:
> D. Peter Siddons wrote:
> 
>>  It has been on my to-do list to use this feature for some time, for a
>>  similar application to Eric's. Since the calls are documented in the
>>  manuals I had assumed they existed! Naive, I suppose... Pete.
> 
> 
> 
> I am using rtems_tarfs_load() in my GeSys application (RTEMS-4.6.2/psim)
> and it works fine... It also builds without hacking.

It was accidentally dropped from a Makefile.am in the post 4.6 
Makefile.am reduction. Just unlucky that no one noticed it.

Just to repeat.. libmisc/untar loads a tar image generically into a 
filesystem of any type and should be portable.   It forces the 
filesystem to create new fiels and storage for them.

The IMFS load tar code is similar and from the same author if I recall 
correctly.  But it has a critical difference -- it leaves the file 
contents in Flash/ROM and only allocates the IMFS control information 
from RAM.  So you an 90+% of the benefit of a true ROM filesystem with
a fraction of the code of a new filesystem.  Plus you use tar to create 
the ROM image -- not some new host tool which we would have to develop 
and keep in sync.

--joel

> -- Till
> 
> 
>>
>>
>>  Ralf Corsepius wrote:
>>
>> > On Fri, 2005-02-04 at 13:41 -0600, Joel Sherrill wrote:
>> >
>> >
>> >> FYI .. this was sent to rtems-users at OARcorp.com not rtems.com.
>> >> They are separate domains and machines now. :)
>> >>
>> >> Eric Norum wrote:
>> >>
>> >>
>> >>> Why is cpukit/libfs/src/imfs/imfs_load_tar.c no longer being
>> >>> built? It looks like just the thing I need for my standalone
>> >>> EPICS IOC.
>> >>>
>> >>
>> >> My guess is probably just an accidental oversight in some
>> >> Makefile.am updates.
>> >>
>> >
>> > Probably, I don't know. Digging CVS-history shows it had been
>> > disabled a very long time ago, and nobody seems to have missed it
>> > :(
>> >
>> >
>> >
>> >> The 4.7 tree uses a lot fewer Makefile.am's and something might
>> >> have been missed.
>> >>
>> >> From what I see it also could be some unfinished work, because it
>> >> shares
>> >
>> > a lot of code with libmisc/untar (Definitely something to be worth
>> > looking after).
>> >
>> > Ralf
>> >
>> >
>> >
>> >
>> >
>> >
> 
> 
> 
> 


-- 
Joel Sherrill, Ph.D.             Director of Research & Development
joel at OARcorp.com                 On-Line Applications Research
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