kernel panic

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worker201
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kernel panic

Post by worker201 » Mon Feb 05, 2007 2:17 pm

Alright, the basic Slackware kernel, 2.4.33.3, has none of the drivers I want. So I pulled the source to 2.6.17.13 off the extras disc and built a kernel from that. Now it recognizes my audio device, my graphics card, and the Synaptics touchpad at boot. However, it runs into a bit of stickiness:

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VFS: Cannot open root device "802" or unknown-block(8,2)
Please append a correct "root =" boot option
Kernel panic - not syncing: VFS: Unable to mount root fs on unknown-block(8,2)
I suspect the problem is that I cannot seem to find the right SATA drivers for my hard drive in the kernel config options. Anyone know how to make sure I get all the right drivers for this?

Also, I would like to know if there is any way to view all the messages from the panicked boot. By the time I have rebooted into the working kernel, dmesg is full up with messages from the successful boot. I'd like to take a look at what's happening at the beginning of the panicked boot.

insomnia
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Post by insomnia » Mon Feb 05, 2007 8:59 pm

I once needed the "pci=nomsi" boot option to see the sata drives on a Debian system (also a laptop)...

As you noticed, the generic kernel from disc 2 is ultra bare. It's very unlikely it will support any new system without fully rebuilding it (it doesn't even support Slack's own default ext3 FS).
With problematic hardware, it's IMO easier to start (and next strip it down) with the huge26.s kernel from disc one.

Don't forget you must install the the modules package from /extra/linux-2.6.17.13 (disc2) for huge26.s as well.

worker201
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Post by worker201 » Tue Feb 06, 2007 12:40 pm

Problem solved. Not exactly sure which of the 2 things I did fixed it, but probably both. The first was to look at a couple kernel configs from Google, and figure out which SATA drivers to include. Second was to run a couple rdev commands:

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rdev -R bzImage 1
rdev bzImage /dev/sda2
I'm not sure why these particular commands appear in the Slackware FAQ but not in the Slackware book.

I did notice that the pre-built 2.6.17.13 kernel from the Slackware disk had troubles recognizing any filesystem but ext2 - however, that gives a different kernel panic error message that I will recognize from now on. Anyway, I am now running 2.6.17.13 with no troubles on an ext3 filesystem. And I have modular support for JFS, XFS, ReiserFS, and NTFS, plus built-in support for ext2, FAT32, HFS, and HFS+.

The best thing about Slackware, by far, is that when you get something working, you feel like a million bucks.

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