lkml.org 
[lkml]   [2004]   [Dec]   [29]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
/
Date
From
SubjectRe: waiting 10s before mounting root filesystem?
On Wed, Dec 29, 2004 at 12:49:02PM +0000, Paulo Marques wrote:
> William Park wrote:
> >[...]
> >
> >Ideally, motherboard should support booting from USB key drive
> >directly. I'm told that most modern motherboards do support usbboot,
> >but my machine doesn't. So, I trying to load the kernel from floppy
> >(harddisk for testing purpose). This is part of my attempt to build
> >Linux thin-client out of mini-ITX type of computer (Via CLE266
> >chipset, Via C3 cpu).
> >
> >Now, I need to find a machine that actually can do usbboot...
>
> You will have the same problem even if the BIOS supports booting from
> USB. The BIOS will load the bootloader and map the USB drive as if it
> were a regular disk, so that the INTxx calls (can't say the number
> from memory) that LILO (or another bootloader) uses to load the kernel
> and initrd into memory will work.
>
> After that, the kernel boots the same way as if it were loaded from a
> floppy. It still needs to discover the USB drive to mount the root
> filesystem, and that will still take the 5 seconds you were
> complaining about.

Ah, right.

>
> As Trent Lloyd already mentioned, you could solve this using a small
> initrd and a "nash" script, instead of patching the kernel, although
> I'm in favor of a patch of this sort getting into mainline.

I read Documentation/initrd.txt and I don't understand it. If I
understand it right, I have to build a complete root filesystem with all
the stuffs necessary for mounting the second (real) root filesystem. If
I'm loading the kernel from floppy, then I only have 200k to work with.
I'll try initrd.txt, step by step over the holidays.

>
> After all, what is the use of kernel saying "Panic, can not mount the
> root filesystem" instead of saying "humm... no root file system there.
> Let me try again in a second or so and see if anything as come up..."?

--
William Park <opengeometry@yahoo.ca>
Open Geometry Consulting, Toronto, Canada
Linux solution for data processing.
-
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@vger.kernel.org
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/

\
 
 \ /
  Last update: 2005-03-22 14:09    [W:0.091 / U:0.156 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site