Re: Iso-hybrid freezing the BIOS on USB key
On 08/11/2011 05:55 AM, Jean-Michel Philippe wrote:
> I'm working on Squeeze to build a Squeeze-based iso-hybrid DoudouLinux
> image. While the image perfectly works on a DVD, it doesn't run on an
> USB key. On my laptop, the key is simply freezing the BIOS!
Some old BIOSes are unhappy booting iso-hybrid. In that case, build and
use usb-hdd images instead.
> I made some
> investigations with sfdisk and found that the partitions are not
> starting at sector 1 but 0 on the image file:
> This results on the USB key in partitions starting somewhere between
> sector 0 and 1. So I wonder if this can not be the origin of the issue.
> Is there a particular option to use with dd when writing the image file
> to the USB key?
No. You just dd the file to the device, e.g. /dev/sdb (*not* to the
> NB: fdisk fails to analyze this image file. It is complaining about a
> wrong partition table: “Error: Invalid partition table - recursive
> partition on”.
Also normal. isohybrid plays "tricks" with the image to make it boot
both as optical media and from USB.
This is from the syslinux wiki:
"The ISO 9660 filesystem is encapsulated in a partition (which starts at
offset zero, which may confuse some systems.) This makes it possible for
the operating system, once booted, to use the remainder of the device
for persistent storage by creating a second partition."
Note: Persistent storage in a separate partition is currently not
working correctly with Debian Live images, though the doc from their
site indicates it should be possible. That remains as a TODO to fix in