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Linux and the JMicron JMB36x Controller

Because I’m an idiot and chose a title that has nothing to do with the post, I’m including this sub-header. Hope people find this more useful.
The price of the latest processors has been reduced so I’m sure there’s going to be plenty of fresh Linux install attempts made on-top of the latest chipsets. There’s even a pretty good chance you’re using a spankin’ new Core 2 Duo. Beware, if you own an Intel Core 2 Duo processor it is very likely that you have a motherboard with either a Intel P965 or Intel 975x chipset. Unfortunately these chipsets don’t support PATA natively (only SATA). Since plenty of computers still use PATA CD-Rom drives or harddrives (they’re so cheap!) most motherboard manufacturers chose to use a separate IDE Controller to support PATA drives (now they are really cheap, but in a bad way!) ,mostly the JMicron JMB36x Controller. Unfortunately there’s a bug in the Linux kernel (fixed in 2.6.18) that causes the JMicron JMB36x Controller not to function properly. The bug also affects the Gentoo LiveCD and most of the other LiveCDs; Knoppix and Ubuntu. Watch out for stuff like;

• “could not find cd to boot, something else needed!”
• “The root block device is unspecified or not detected”
• “no bootable medium found”
• “unable to find filesystem”

Fortunately there are fixes. Best tried in this order;

• Wait for a livecd that uses the latest kernel; 2.6.18-rc that includes the bugfix.
• Boot from the LiveCD using the all-generic-ide parameter. You’re bound to get some errors and DMA mode may not be available (ouch that’s a real killer).
• Use a SATA, USB or Firewire optical drive for the installation.
• Use a PATA optical drive to a SATA converter.
• Use a USB or Firewire optical drive.
• Use a separate PATA Controller.
• Use a bootable USB thumbdrive along with a smaller distribution.