Re: Booting a CF or SD card from an internal card reader
On Fri 05 May 2017 at 13:53:00 (-0400), Stefan Monnier wrote:
> >> Of course it all depends on what you mean by "booting from". AFAICT in
> >> Leandro's situation, he's loading Grub from some other disk (probably
> >> the main HDD or SSD), so he's already "not booting from the SD card" in
> >> this sense.
> > By "booting from" I mean everything which is needed to bring the OS up
> > is located on the SD or CF card.
>
> AFAIK in his case, Grub itself is already on another device because the
> BIOS can't boot directly from the SD card. So, he can't "boot from" his
> SD card using your definition.
>
> > In essence, the card can be transferred to to another machine and will
> > still boot. What you describe below I'd refer to as "booting into the
> > OS" ; it cannoot be done without the assistance of software on the
> > machine itself. I hope this is not an artificial distinction.
>
> I fully agree: I myself tried to setup a "rescue USB key" that could
> boot everywhere, but that simply can't work on those machines whose
> BIOS simply doesn't know how to boot from USB.
>
> > In principle this is a viable booting method but there are issues to be
> > aware of.
>
> Oh, yes.
>
> > The kernel on the main HDD or SSD is unlikely to be the Tails
> > kernel so a third device would be needed to hold such a kernel;
>
> You don't need a third device. You need to consciously/carefully save
> your Tails kernel and initrd somewhere on the HDD/SSD. You can use
> a separate "TAILS-BOOT" partition on that HDD/SSD for that, or you can
> place them in "the normal partition" but under a special name like
> "vmlinuz-tails" and "inird.img-tails".
I'm using a third device here for a different reason: what I'm booting
is the netinst d-i, so the files on the hard drive will be blown away.
I've booted From the pre-existing Grub2 on the hard drive, but Into
the netinst.iso file on a FAT USB stick by loop-mounting it (Brian's
terminology).
That works fine until the d-i tries to read the "CD-ROM", but then
it's simply a matter of pulling the FAT stick, inserting another one
where netinst.iso has been copied to /dev/sdX itself (not to a FAT
filesystem) and pressing Continue.
> > The OP in the original thread actually booted in this way from the hard
> > disk, but (as it fortuitously happened) kernel, initrd and OS on hard
> > disk and SD card were identical.
>
> That must have been "beginner's luck", indeed.
Actually, I think it was more because they used a sole Debian DVD for
installing both the hard drive's system and the one on the SD. The
OP in the original thread is probably one of the most experienced
d-i installers on this list.
Cheers,
David.
Reply to: