Arch Linux

Arthens

Member

Registered: 2009-01-05

Posts: 6

kinit: cannot open root device dev(8,4)

Hi guys, I need your help

Yesterday I compiled my own kernel. Basically I compiled each driver in the kernel and the only loadable module is the nvidia driver.
After compiled the kernel I built my new initcpio.

When I boot a get these error:

/bin/mknod "dev/root" b 8 4
/init: 1 cannot open /dev/root: No such devices or address
modprobe: FATAL: Could not load /lib/modules/2.6.28.2-ARCH/modules.dep: No such files or directory
Kinit: cannot open root dev (8,4)

I tried to search for a solution in the forum and in the wiki, but I've not been lucky

/boot/grub/menu.lst:

title           Arch Linux Custom
root            (hd0,3)
kernel          /boot/vmlinuz26-r3 root=/dev/sda4 ro vga=0x318
initrd          /boot/kernel26-r3.img

/etc/rc.conf:

MOD_AUTOLOAD="yes"
MODULES="nvidia"
DAEMONS=(hal kdm syslog-ng network netfs crond)

/etc/mkinitcpio.conf:

MODULES=""
FILES=""
BINARIES=""
HOOKS="base udev autodetect sata usbinput keymap filesystems"

userlander

Member

Registered: 2008-08-23

Posts: 413

Re: kinit: cannot open root device dev(8,4)

Same problem here, except mine is (8,2). We must be doing something wrong, but I can't find out what it is. Did mkinitcpio change in some way recently? I'm not booted into my system to see if there's a .pacnew file.

////////////

I solved my problem - it was a hardware configuration issue. What is your drive and device configuration?

Last edited by userlander (2009-01-30 18:29:26)

Arthens

Member

Registered: 2009-01-05

Posts: 6

Re: kinit: cannot open root device dev(8,4)

I solved my problem - it was a hardware configuration issue.

Do you mean that you solved it changing the kernel?
That would be something, because I don't know yet if it's a kernel problem or a initcpio problem

What is your drive and device configuration?

It is a SATA disk (on a laptop) and I'm compiling the kernel with the sata driver.
May I ask what was exactly your problem?

userlander

Member

Registered: 2008-08-23

Posts: 413

Re: kinit: cannot open root device dev(8,4)

I solved my problem - it was a hardware configuration issue.

Do you mean that you solved it changing the kernel?
That would be something, because I don't know yet if it's a kernel problem or a initcpio problem

What is your drive and device configuration?

It is a SATA disk (on a laptop) and I'm compiling the kernel with the sata driver.
May I ask what was exactly your problem?

No, I had to change my hardware hookups. Since you're on a laptop, that probably wouldn't apply.

If you can boot the stock kernel, I would guess that you are leaving out a required module in your kernel configuration somewhere. I would suggest to boot the stock kernel (or maybe a live CD) and look at lsmod and see what you might be missing. Have you built in support for your filesystem?

Arthens

Member

Registered: 2009-01-05

Posts: 6

Re: kinit: cannot open root device dev(8,4)

No, I had to change my hardware hookups. Since you're on a laptop, that probably wouldn't apply.

What do you mean? Do you mean that you changed your hwd configuration and you forgot to adjust the hooks array to the new configuarion?

Would guess that you are leaving out a required module in your kernel configuration somewhere. I would suggest to boot the stock kernel (or maybe a live CD) and look at lsmod and see what you might be missing. Have you built in support for your filesystem?

I'll check again

Arthens

Member

Registered: 2009-01-05

Posts: 6

Re: kinit: cannot open root device dev(8,4)

Mmmm I don't understand.
I used this guide to use lsmod to track each module my system needs, I compiled them into the kernel but I still get kernel panic.

I used this guide to compile the kernel and create the initcpio, do I have to do something else?
I've read in other topics that you should update the system when you install a new kernel, but do you have to do it when you compile your own kernel? If yes, what _exactly_ do you have to do?

Thanks