RE: filesystem for linux embeded system

> -----Original Message-----
> From: sami##B13888# [SMTP:sami_at_hei.co.kr]
> Sent: Wednesday, November 29, 2000 10:24 AM
> To: handhelds_at_handhelds.org
> Subject: [Handhelds] filesystem for linux embeded system
>
> Hi,
>
> I just have a question about root filesytem for linux embeded system.
> Because the embeded sysem has a small size of storage compared to PC system,
> I think it is important to know how to use that storage device efficiently.
        [Simon Wood]
        Agree....

> For my case, I use 16 M Flash ROM and 32 DRAM which are mapped in CPU
> memory map. So I can use flash rom as a real memory unlike disk-on-chip.
        [Simon Wood]
        Sounds interesting... can you supply more information on how this is arranged? I mean are you using the 'execute in place' idea for the kernel/applications?

> At first, I created root filesystem using ROM filesystem and download it to
> Flash ROM. But it is not good idea to use ROM FS image as a root FS
> in a short time because most Linux programs tried to read and write in the root
> FS.
>
> Now I'm using ext2 FS as root FS, but I have to relocate root FS to RAM from
> Flash ROM and it consumes around 10 Mb RAM.
        [Simon Wood]
        Have you tried Minix?? It's a little lighter than ext2.

> Is there any other filesystem which can use both RAM and Flash at the same time?
> I mean I think that it doesn't necessary to move entire root FS image from ROM to RAM.
> I think most files of the root FS can be remained in ROM. But some files and
> newly created files should be in RAM.
        [Simon Wood]
        I theory any files system can be used on Flash/Ram, obviously there are some problems with writing to flash memory. There is a project 'MTD' which has all sorts of flash drivers and specilist filesystems.
        http://www.linux-mtd.infradead.org/

        You might be able to follow SuSE's Live disk image where it uses a ext2 filesystem with lots of links to the files on CD, this way the link can be removed and the files can be 'altered'.

> Please let me know how other people figure out this.
>
>
> Regards,
>
> Jungjun Kim
>
Received on Wed Nov 29 2000 - 03:31:36 EST