My motherboard (VIA Epia) support booting from USB-FDD, USB-ZIP, USB-HDD and
USB-CDROM. I have no idea how it works and what the difference between all
this methods. My USB flash device could be formatted as bootable under
Windows as USB ZIP device, and when I set boot from USB ZIP in BIOS - all
is fine, and I see a: DOS prompt. But setting USB HDD or USB HDD or USB
CDROM as boot device at BIOS fails - boot block cannot be found.
The problem is that FreeBSD boot block (boot0, boot1 or boot2 - I don't
know) assumed that booting is performed from HDD device, but it is untrue.
Maybe I should use different boot blocks? Is it possible to boot FreeBSD
form ZIP device (seen by BIOS as ZIP, not HDD or FDD)? I know that we have
different boot block to boot from CD (/boot/cdboot) and maybe we should have
something like /boot/zipboot?
Anton L. Vinokurov, CCNA
[EMAIL PROTECTED]
NeTAMS Development Team
USB booting support is down to two things: BIOS and kernel support.
If the BIOS can probe and boot from it in a similar way to how one might
boot from an El Torito CDROM, then the BIOS has done its bit.
Going further, some BIOSes support making these devices visible to DOS, I
assume - I don't have any first hand experience of this.
The problem here is that you won't even get as far as the loader *unless*
the BIOS is able to interpret the USB device as a hard disk drive. If the
BIOS emulates a fixed disk device in a traditional sense then standard
boot code will work fine.
However, if its USB boot emulation doesn't extend to the BIOS
interrupts used by the standard FreeBSD boot sector, you won't even get
as far as the loader.
Once the kernel has started to boot, it will need to have a disk driver
which
can understand the disk it's booting from, otherwise it will fail to mount
root.
I don't have time to do further research on this right now but I suggest
you contact your BIOS vendor for information, or research on their web
site.
BMS
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