[plug] SATA boot problem

[Jim Householder]

Daniel Pittman wrote:
> Jim Householder <nofixed at westnet.com.au> writes:
> 
>> I have just bought a 500GB SATA Seagate Barracuda drive, and have built a
>> kernel on it with all the SATA options I could find built-in (not modules).
>>
>> When I boot from the drive it gets as far as trying to mount / and panics.
>> A list of partitions available does not show the SATA drive, event though
>> the code that aborted was executed from it.
> 
> Do you mean "was executed from it" in the sense of "GRUB loaded the initrd and
> kernel from it?"

yes, but no initrd - just vmlinuz

> 
> Is the panic, specifically, that it can't find the root device?
> 
> When you say "A list of partitions", where is that coming from and what does
> it show?
> 
This is a summary of what I see:

...
md: Waiting for all devices to be available before autodetect
md: If you don't use raid, use raid=noautodetect
md: Autodetecting raid arrays.
md: Scanned 0 and added 0 devices.
md: autorun...
md: ... autorun done
VFS: Cannot open root device "sda2" or unknown-block(0,0)
Please append a correct "root=" boot option; here are the available
partitions:
0300 <size> hda driver: ide-gd
0301 <size> hda1
...
0308 <size> hda8
0340 <size> hdb driver: ide-gd
0341 <size> hdb1
...
034f <size> hdb15
1600 <size> hdc driver: ide-cdrom
Kernel panic - not syncing: VFS: Unable to mount root fs on
unknown-block(0,0)
_

>> Since code from the drive is already being executed, that does not seem to
>> be the problem.
> 
> You are probably wrong, and the answer to the question WRT the bootloader
> above will confirm that.  My guess is that Linux has never seen the drive,
> even though the BIOS can.

Exactly.  Why can the kernel not see the drive?
> 
> Now, one last question: why are you building a custom kernel rather that using
> the distribution option?  The distribution will almost certainly have the
> right drivers available and configured sensibly, so you can avoid this problem
> of doing it yourself entirely...
> 
I'm using gentoo, and I do not want the kitchen sink!

I may have to get it though, if I cannot sort this out.

Jim