I'm replying via Yahoo web, so sorry about formatting... text option is nowhere to be found.
A solution that almost worked is "memdisk" from Syslinux. Essentially, you configure the usual "syslinux.cfg", but your kernel is "memdisk" and your initrd is the ISO image you want. I say "almost worked", because
- it boots the ISO you want -- you see dots filling up the screen
- ISO boots -- you see its boot splash
- then, it complains that it can't find the live filesystem that it just loaded.
All other solutions I tried or read about, extracts ISO and puts the content into partition. That's not what I want. Also, you forget which partition is what OS, and end up putting new release ISO into wrong partition.
I want to keep the downloaded ISO as is.
Old ISO designed for pure CD/DVD will not boot off USB, because it doesn't have harddisk emulation layer. You can tell by 'fdisk -l'. If it shows partition, then it has harddisk emulation. You can turn those old ISO into bootable ISO using 'isohybrid', but this modifies the ISO file.
Nowdays, all Linux/Windows ISO can boot off USB. You can even install Windows onto USB stick and boot off it, but few things doesn't work, like "Windows Update". :-)
Still looking... Heck, time I spent on this, it would be cheaper to just buy a pack of USB sticks.
--
William
On Tuesday, September 29, 2015 9:42 AM, D. Hugh Redelmeier <hugh@mimosa.com> wrote:
| And the dd of one ISO also only works in the case that it is actually
| and image capable of working from USB instead of a CD/DVD, which is
| certainly true for many these days but is also not generic.
I have found that creating bootable USB sticks from dd-ing .iso files
to work very well for those distros that intend it.
This mechanism doesn't allow you to store other goodies on the stick.
I would like to have a convenient place to store my customization
data: some packages I always install, some updates to avoid repeated
fetching from the internet, some public keys, etc. Only the
unetbootin-like processes seem to support this.