Re: Suggestions for CD images - following CD talk at Debconf
On Sat, 2015-08-22 at 11:34 +0000, Andrew M.A. Cater wrote:
> On Sat, Aug 22, 2015 at 08:41:36AM +0100, Ian Campbell wrote:
> > On Fri, 2015-08-21 at 22:26 +0000, Andrew M.A. Cater wrote:
> > >
> > > [Off topic for _this_ list: I've got UEFI netboot working with
> > > bootnetx64.efi which is different from the grub etc. for CD/DVD -
> > > which is iikely to continue?
> >
> > I'm not sure what the question is, are you asking if UEFI netboot is
> > likely to continue to be supported? I think so, yes.
> >
> [Extended to debian-efi list because this overlaps]
>
> Sorry, I wasn't being clear:
>
> "Legacy" PXE boot over the network and UEFI boot don't appear to work
> together well.
>
> If the PXE server is set up to serve pxelinux.0 and you switch your
> computers boot mechanism to UEFI rather than CSM compatible/legacy
> mode then the process will fail silently and you are left wondering
> what you did wrong.
The DHCP server should be configured to serve the right thing (~= PXE
payload) for the machine, this can (apparently) be done automatically
using the arch option according to e.g. https://access.redhat.com/docum
entation/en-US/Red_Hat_Enterprise_Linux/6/html/Installation_Guide/s1
-netboot-pxe-config-efi.html
>
> This is now becoming more important with some motherboards not supporting
> "legacy" settings, with the Bay Trail machines having 32 bit UEFI and 64
> bit processors - thanks for the fact that this now just works, Sledge.
>
> Different distributions handle this UEFI net booting differently:
This is partly because unlike with Legacy boot there is no de facto
standard for the PXE payload (which is what pxelinux.0 is for Legacy
world).
So each distro ends up building its own grub image to use as the PXE
payload, and that grub requires its own corresponding set of modules in
the PXE dir. Note that one distros "bootnetx64.efi" may not be anything
like another distros "bootnetx64.efi".
In theory you can put your own grub image into your PXE infra and use
each distros grub.cfg (ignoring their grub modules etc) via that,
hoping that the distro isn't relying on features of their own specific
grub binary.
The only real solution here is for a new de facto standard for PXE
payload to arise for the UEFI world or for someone to proactively talk
to all the distros and define such a thing.
> CentOS 6 _ought_ to work with bootnetx64.efi - but doesn't appear to
> for me.
>
> Debian 8 Jessie can use bootnetx64.efi - serve that from your TFTP
> server
> with all the other files from the default debian-installer available
> in /srv/tftp and you get
> a text mode install which actually works quite well.
>
> Ubuntu 14.04 LTS uses grubnetx64.efi.signed and a special grub.conf
> file. This produces a minimal
> install but you can then add e.g. ubuntu-desktop.
>
> CentOS 7 can also use a grubnetx64 and a similar grub.conf file. If
> you invoke the right parameters
> you end up in a full graphical install.
>
> UEFI installation media - the Jesie netinst.iso, for example, appears
> to use grub - not bootnetx
"bootnetx" _is_ grub, I think you are assuming it is something else
because of the name? It's not, it's just grub, configured/built for
network booting. (I'm not sure if the name scheme comes from UEFI spec,
which does define BOOT$ARCH.EFI for non-network boot, or if someone
just made it up at some point).
BTW the "x" in bootnetx64 binds to the 64, i.e. it is "bootnet" for the
"x64" architecture. Likewise in grubnetx64.
> Are we likely to move to the grubnetx64.efi / grub.conf method for
> UEFI network booting?
Given that bootnetx64.efi _is_ grub other than the name of the file to
be delivered as the PXE payload what exactly are you asking to change?
The the client system the name is irrelevant anyway, it just sees the
pxe payload.
Ian.
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