[U-Boot-Users] ROMFS & Uboot.

[Christophe.LINDHEIMER at fr.thalesgroup.com]

Hi.

> > 
> > Well, my problem is that I am really short of ram.
> 
> Easy to fix: add more RAM. RAM is very cheap these days.

Harder to fix : explain hardware people that they shouldnt care about
current consumption and area of the card :-)

> 
> > So I would like to have my filesystem in flash and keep it in flash.
> > 
> > So I would like to have my root filesytem in flash ( possible ?? ).
> > romfs seems to be a way to do it.
> 
> Of course this is possible. And there  are  many  ways  to  implement
> this: romfs, cramfs, jffs2, ...
> 
> > It think the way to do it it to declare my romfs as initrd 
> ( maybe I am
> > wrong because initrd is init ram disk and it means that it 
> MUST be a RW
> > filesystem in RAM ??? )
> 
> Right. An initrd is a RAM disk. And a RAM disk is in RAM by 
> definition.
> 
> > After reading sources of U Boot it seems that if I put a 
> second parameter at
> > bootm, it is going to copy the initrd into RAM ( right ? ).
> 
> Not really. Current versions of U-Boot allow to avoid the extra  copy
> of  the  ramdisk  image. But the LInux kernel will load the initrd to
> RAM in any case.
> 
> > whereas I would like to keep my romfs in flash.
> 
> Then use a flash filesystem.
> 
> > maybe I misunderstand and misuse completly the initrd... 
> Help and hints
> > welcome...
> 
> Have a look at the MTD layer. You have to enable MTD support  in  the
> Linux kernel. Then you can define partitions on your flash memory and
> create  block  devices  on  these. And on these block devices you can
> uses filesystems - whichever you like.
> 
> 
> But all of this is actually completely unrelated to U-Boot  and  thus
> off topic here.
> 

Ok . thanks for help. I gonna look this.

Regards

Chris