Trouble using initrd : no cpio magic

Linux.tar.gz · 04-08-2007, 12:01 PM

I made an initrd following Patrick Volkerding's instructions:
http://mirrors.dotsrc.org/slackware/.../README.initrd

but when i boot, i have a kernel panic : no cpio magic.
Some ideas ? Need some info ?

erklaerbaer · 04-08-2007, 03:27 PM

the error message is indeed right. mkinitrd does not create a cpio archive, but a gunzipped ext2 filesystem.
i don't ave any special idea. never saw that message.
we'll need some more info. custom kernel, root filesystem, etc.

Linux.tar.gz · 04-08-2007, 04:16 PM

Kernel 2.6.20.4.
Reiserfs.
Mobo chipsets and reiserfs built inside the kernel.

Alien Bob · 04-08-2007, 04:41 PM

Quote:

Originally Posted by erklaerbaer

we'll need some more info. custom kernel, root filesystem, etc.

Also, what version of Slackware? How up to date on the patches? Anything special installed that changed/replaced core libs?

Eric

erklaerbaer · 04-08-2007, 04:58 PM

apropops, do you, eric, know why slackware doesn't use an cpio initramfs? seems to be the standard for 2.6 kernels. at least it's what everybody else is doing^^

Alien Bob · 04-08-2007, 05:03 PM

Quote:

Originally Posted by erklaerbaer

apropops, do you, eric, know why slackware doesn't use an cpio initramfs? seems to be the standard for 2.6 kernels. at least it's what everybody else is doing^^

I guess the mkinitrd script in slackware-current will sometime be upgraded to use an initramfs before it hits stable. The initrd image that is used in the Slackware installer already is an initramfs.

Eric

Linux.tar.gz · 04-08-2007, 05:25 PM

Slackware-11, all patches applied and no core libs replaced.

erklaerbaer · 04-08-2007, 06:08 PM

init/initramfs.c

Code:

/**
 * memcmp - Compare two areas of memory
 * @cs: One area of memory
 * @ct: Another area of memory
 * @count: The size of the area.
 */

Code:

static int __init do_header(void)
{
	if (memcmp(collected, "070701", 6)) {
		error("no cpio magic");
		return 1;
	}

Code:

static int __init do_collect(void)
{
	unsigned n = remains;
	if (count < n)
		n = count;
	memcpy(collect, victim, n);
	eat(n);
	collect += n;
	if ((remains -= n) != 0)
		return 1;
	state = next_state;
	return 0;
}

does it work with a stock kernel?

Code:

grep CONFIG_BLK_DEV_INITRD .config
greo CONFIG_BLK_DEV_RAM .config

?

Linux.tar.gz · 04-15-2007, 06:30 PM

From the -current changelog :

a/cpio-2.5-i486-3.tgz: Recompiled. Newer versions break initramfs in the
2.6.18.x kernels, so we'll still have to wait on an upgrade...
Fixed broken manpages. Thanks for the reports from Tsomi and Lilong Li.

Alien Bob · 04-15-2007, 10:42 PM

That has nothing to do with it. The cpio in Slackware was never broken. An initramfs is already used on the install CD for instance.
Only newer versions of cpio are problematic.

Eric

Linux.tar.gz · 04-17-2007, 08:43 AM

Roger that.
I'll try at next kernel version, and i'll compile some stuff inside kernel instead of modules.