Building LFS/BLFS on USB.

Tijnema ! tijnema at gmail.com
Thu Apr 5 13:06:14 PDT 2007


On 4/5/07, Michael Shell <list1 at michaelshell.org> wrote:
> On Thu, 5 Apr 2007 18:46:44 +0200
> "Tijnema !" <tijnema at gmail.com> wrote:
>
> > Somehow i even needed to mount /dev/sda to get the first(and only)
> > partition on my USB stick.
>
>
> It's just like a hard drive. You've got to run fdisk on it:
>
> fdisk /dev/sda
>
> and create a single ext2 primary partition. Then, after formatting
> it:
>
> mke2fs -v -L volume_label /dev/sda1

I did above steps, and in a fully working environment i was mounting
/dev/sda1, but using a floppy disk from other distribution it required
me to mount /dev/sda, and /dev/sda1 didn't work.
>
> you can access it as /dev/sda1. The LS120/Zip drives were
> the same way - sometimes people would just format the whole
> disk (/dev/hdc), other times they would partition it (/dec/hdc1).
>
> On more modern machines, the BIOS supports booting directly
> to USB. However, this may require a USB drive that provides
> "USB-ZIP" or "USB-HDD" boot support. Only about 30% of flash
> drives have such support:
>
> http://arstechnica.com/reviews/hardware/flash2005.ars/2
>
> also note: http://syslinux.zytor.com/usbkey.php

I know that some BIOSes to this, but this is a school project, and
these PCs are quite old. Here at home i have 3 test PCs for this
project. 1 is about 10-15 yrs old, one is about 5-10 yrs old, which
both don't support USB booting, and i have another PC here, which is
only a few months old, and USB booting is fine, but at school it
doesn't work, and so i want to use a floppy for this instead.
>
>
> If your BIOS allows you to boot directly to your USB drive, then
> that would be the way to go.
>
> If booting from BIOS requires such features as seems to be the
> case, that is so bogus. IMHO, they never did properly address the
> BIOS boot architecture. In my opinion, every motherboard should
> have come with an internal non-volatile memory (which today could
> be a slot for an SD card) right from the earliest days when 1MB
> flash became affordable - the contents of which can be saved/loaded
> and used as a device to hold a boot loader. That is, every motherboard
> needs to have a standardized boot device we can always count on, which
> is large enough to hold the needed boot loader .... I know, I know,
> it's called a hard drive, but these guys can get into trouble
> and need to be externally "rescued". Sigh. I just don't like the
> situation where we have all of these devices that the BIOS doesn't
> directly support, and have no easy way to jettison the BIOS entirely
> with a full OS (Linux) which can then be used as a platform to
> boot all the other OSes.
>
> I think the LinuxBIOS project is a good approach:
> http://linuxbios.org/
> however, there is always the issue of whether a given motherboard
> is supported.
I'll take a look at it :)
>
> However, I've never done a case where a small kernel is booted
> from a floppy (or CD for that matter) so as to gain access to
> the needed USB drivers, and then a second, larger, kernel is
> invoked from the USB drive. I don't know the ways this can be
> done. One is via kexec, but it looks tricky:
>
> http://www-128.ibm.com/developerworks/linux/library/l-kexec.html
>
> It would be nice if someone could could go over the various
> approaches to booting a larger kernel (on a USB drive) from a
> small initial kernel (on a floppy or CD).
>
>
>  Mike Shell

I didn't want to reload the kernel, i just wanted to load additional
modules after mounting the USB stick.
Anyway, thank you for your reply, some good links :)

Tijnema
>



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