Re: Specify devices manually in exotic environment

From: Milan Hauth
Date: Wed Aug 23 2006 - 07:12:37 EST

On Wed, 23 Aug 2006 12:10:27 +0200, Denis Vlasenko
<vda.linux@xxxxxxxxxxxxxx> wrote:

> mknod /dev/root b "$ROOTMAJ" "$ROOTMIN"

This also did not help -- 'cat: /dev/root: No such device or address'.
Major/minor is 4/0, as recommended in the kernel docs for /dev/root.

What cat? Where did I say to cat anything? I said "create new node,
namely, 'root', in the /dev, with the following major/minor#".

I did create the root node (b4/0). Just used cat for testing, since I
didn't have dd available yet on the initrd. But obviously it did not
work.. :-\

If it doesn't work, maybe your initrd is mounted ro.
Remount it rw first. Or mount a ramfs somewhere,
it will give you writable place to play.

So where can I find my flash memory..? Again, with GRUB I just had to
specify the device address (0x80) and the kernel/initrd positions in
sector syntax, which works fine. Maybe I can do the same in Linux with my
ext2 partition, to specify the start and end sectors ('Specify drives
manually..'). But where to start?

Start by reading boot messages. They ought to say
what devices are found.

Ah, excellent: A IDE controller is found:

CS5530: IDE controller at PCI slot 0000:00:12.2

The according line in lspci:

00:12.2 0101: 1078:0102

And there are also two IDE interfaces:

PCI: Setting latency timer iof devvice 0000:00:12.0 to 64
ide0: BM-DMA at 0xfb00-0xfb07, BIOS settings: hda: pio, hdb: pio
ide1: BM-DMA at 0xfb08-0xfb0f, BIOS settings: hdc: pio, hdd: pio
Probing IDE interface ide0...
Probing IDE interface ide1...

..but no devices, which is logical: If there would be devices, I could use
them via /dev/hd*.

But why is the IDE controller being recognized, while no devices are

Try hexdump'ing your sd devices:

# dd if=/dev/sda bs=1024 count=1 | hexdump

and see whether they give something like boot sector.

'No such device or address'.. I already tried special devices before,
forgot to mention.

Maybe I just gonna try to get some more information about my hardware and
recheck my Kernel configuration..

Cheers, milahu
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