Re: Specify devices manually in exotic environment

Milan Hauth
2006-08-23T11:15:03Z

On Wed, 23 Aug 2006 12:10:27 +0200, Denis Vlasenko
<vda.linux@googlemail.com> 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
found..?

> 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..