root=/dev/ram0

Peter Ryser Peter.Ryser at xilinx.com
Fri Jul 27 16:52:27 EST 2001


Hi Andy,

configure your kernel with
- ramdisk support
- ramdisk support as boot device
- extended fs 2 support


make a minimal ramdisk consisting of the files/directories
/linuxrc
/dev/console
where
/linuxrc is a copy of sash
/dev/console is created with: mknod /dev/console c 5 1

compress the ramdisk and move it to
linux/arch/ppc/boot/tree/ramdisk.image.gz

There are two different ways to set the kernel command line (eventually in
linux/arch/ppc/boot/tree/main.c)
- leave it empty (do it this way for a start)
- set it to: root=/dev/ram0 init=/linuxrc rw

Build the kernel: make zImage.initrd

Download the image and boot.

I hope this helps

- Peter

Andrew Dixon wrote:

> Hi All,
> I'm trying to mount a compressed ramdisk image on /dev/ram0 and run my
> root filesystem from there.  My problem is that when I try to boot I get
> the following error:
>
>     VFS: Cannot open root device "ram0" or 01:00
>     Please append a correct "root=" boot option
>
> earlier in the boot process the ram disks are recognized:
>
>     RAMDISK driver initialized: 16 RAM disks of 4096K size 1024
> blocksize
>
> I'm using kernel 2.4.5-pre3 from Ben H's source.
>
> Anyone know why the kernel isn't able to open /dev/ram0?
>
> Thanks,
> Andy
>


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