Ashwin,

Compression is only an option for mkifs.  If the "[+compressed]"
attribute is not specified, then there is no decompression necessary.

If  you don't want the IFS copied to RAM at all, then you can use the
"[image=]" and "[ram=]" attributes to create an eXecute-In-Place (XIP)
image.  If you do use XIP, then it is not allowed to run devf- or
fs-etfs on the same flash device as the IFS.

As Premachandra mentioned, the documentation for mkifs and in "building
embedded systems" will explain the details of how to do this.

David 

> -----Original Message-----
> From: Ashwin Patwekar [mailto:community-noreply@qnx.com] 
> Sent: August 4, 2009 7:31 AM
> To: general-filesystems
> Subject: RE: Cramfs like alternative in QNX?
> 
> Unlike a compressed image of a conventional file system, a 
> cramfs image can be used as it is i.e. without the need to 
> decompress the image first. 
> [http://en.wikipedia.org/wiki/Cramfs]
> 
> This way you can have your compressed image located in 
> rom/ram and use it as a regular readonly filesystem.  
> 
> AFAIK mkifs supports compression but before use the file 
> system needs to be decompressed(which consumes RAM space). 
> 
> Thanks,
> Ashwin
> 
> 
> -----Original Message-----
> From: Premachandra Mallappa [mailto:community-noreply@qnx.com]
> Sent: Tuesday, August 04, 2009 4:46 PM
> To: general-filesystems
> Subject: Re: Cramfs like alternative in QNX?
> 
> Hi Ashwin,
> 
> Please go through the documentation, building embedded systems.
> 
> There is a buildfile which specifies what files should go on 
> the final image and what path.
> It is somewhat similar to Linux equivalant of 'initramfs' 
> with a filesystem built into kernel image.
> 
> look into mkifs documentation for more information on how this works.
> 
> Cheers,
> /Prem
> 
> 
> 
> _______________________________________________
> 
> General
> http://community.qnx.com/sf/go/post35158
> 
> 
> 
> 
> 
> 
> _______________________________________________
> 
> General
> http://community.qnx.com/sf/go/post35159
> 
> 

Take a look at the "inflator" program.  It will provide transparent file
decompression, and only decompresses one decompression buffer (default
8k) when needed.

David 

> -----Original Message-----
> From: Ashwin Patwekar [mailto:community-noreply@qnx.com] 
> Sent: August 4, 2009 7:31 AM
> To: general-filesystems
> Subject: RE: Cramfs like alternative in QNX?
> 
> Unlike a compressed image of a conventional file system, a 
> cramfs image can be used as it is i.e. without the need to 
> decompress the image first. 
> [http://en.wikipedia.org/wiki/Cramfs]
> 
> This way you can have your compressed image located in 
> rom/ram and use it as a regular readonly filesystem.  
> 
> AFAIK mkifs supports compression but before use the file 
> system needs to be decompressed(which consumes RAM space). 
> 
> Thanks,
> Ashwin
> 
> 
> -----Original Message-----
> From: Premachandra Mallappa [mailto:community-noreply@qnx.com]
> Sent: Tuesday, August 04, 2009 4:46 PM
> To: general-filesystems
> Subject: Re: Cramfs like alternative in QNX?
> 
> Hi Ashwin,
> 
> Please go through the documentation, building embedded systems.
> 
> There is a buildfile which specifies what files should go on 
> the final image and what path.
> It is somewhat similar to Linux equivalant of 'initramfs' 
> with a filesystem built into kernel image.
> 
> look into mkifs documentation for more information on how this works.
> 
> Cheers,
> /Prem
> 
> 
> 
> _______________________________________________
> 
> General
> http://community.qnx.com/sf/go/post35158
> 
> 
> 
> 
> 
> 
> _______________________________________________
> 
> General
> http://community.qnx.com/sf/go/post35159
> 
>