Re: second-stage bootloader for Thecus N2100?
(PS: Obviously I meant "the 1st one" in my original mail and the
followup-incorrection).
On Sat, 31 Jan 2009, Loïc Minier wrote:
There are many solutions to the first part, perhaps our preferred
is when the bootloader is clever enough to e.g. boot from USB or SD
card first, or even clever enough to offer you a list of kernels
from a partition on your SATA disk!
Yeah, shouldn't be /too/ hard to do. A little shell or AWK script
could do the job (for a prototype).
explored building an env from kboot and petitboot.
Interesting, I'll look those up.
With kboot/petitboot, you're bloating the initramfs size, probably
would still fit in the case of the Thecus N2100 though (in our
case, even a standard initramfs wouldn't fit).
The n2100 has a decent amount of flash, so that shouldn't be a huge
problem.
Also, this is no silver bullet: you still want to be able to
recover from breakage in the flash's kernel/initramfs, or upgrade
them (even if less regularly), and it will require starting two
kernels, hence making boot times longer.
Once the linux-bootloader works, changing it should be rare, indeed.
You also face a prompting problem on the Thecus N2100 which doesn't
have a display/console by default (you can of course solder it in, but
that's less user friendly ;-) and going the telnet/ssh route might
make it a) insecure b) slower to boot c) tricky to actually log in
during the open window.
I was thinking you could:
- syslog the results of the boot env (so you could at least know if
you'd broken a config file - you can always access the disk by
booting the debian netinst)
- have a fallback option (though, this would require modifying some
state shared between loader and booted environment which, ideally,
would be in NVRAM - is that possible with redboot?)
https://lists.ubuntu.com/archives/ubuntu-devel/2009-January/027229.html
https://wiki.ubuntu.com/Specs/ARMSoftbootLoader
Why build a new environment? Why not use the standard Debian initram?
What modifications are needed other than to go down a 'read and offer
boot menu and kexec' path instead of flipping to the root dev?
Least, that's what I was thinking of using as a starting point. Just
curious what reasons there are for going another way.
Thanks!
regards,
--
Paul Jakma paul@clubi.ie paul@jakma.org Key ID: 64A2FF6A
Fortune:
An expert is a person who avoids the small errors as he sweeps on to the
grand fallacy.
-- Benjamin Stolberg
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