Clarifications of downloadable file types

Jay Vaughan jayv at
Thu Jul 10 21:39:46 CEST 2008

> *.tar.gz - I know what a tarball is, but when the same filename  
> exists with both a jffs2 and a tar.gz extension, do they contain the  
> same thing? Why? Is the tar used with an emulator? Would I ever need  
> it for the real device?

.jffs2 is for burning to the device, .tar.gz is a copy of the same  
filesystem in case you want to set up a root-on-sd environment ..

> What is considered the "image"? It seems to me that it is the jffs2,  
> not the kernel. However, the kernel files have the word "image", so  
> I am either wrong or very confused.

There are three components burned into your FR's NAND .. the u-boot  
bootloader, the kernel image, and the filesystem distribution.  The  
filesystem contains a full-blowing linux setup, the kernel is just  
that - a kernel, and u-boot is the first thing your FR runs when it  
starts up ..

> Lastly, does each image have a corresponding kernel so flashing to a  
> new distribution would always require flashing the kernel as well?  
> If not, how can I know when flashing the kernel is also required?

Kernels are released periodically in the current build hosts, but the  
rule is if you don't see one released with a new .jffs2/.tar.gz image,  
use the latest one before it .. not all releases need a kernel update,  
just a new filesystem tweak or two ..

> Is this information on the wiki somewhere and I just missed it?

Do a search for 'dfu utility' on the wiki for more details ..

Jay Vaughan

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