(2016-02-15 10:58)FreeMinded Wrote:  Hi iPXE community

I'm pretty new to iPXE, so please bear with me.

We are trying to use iPXE to achieve the following:
In a distributed setup we want the clients (Desktops or Notebooks) to ask a defined server what to boot. In the normal case this would just be to boot Windows from the local hard drive. But when necessary the server can instruct the client to boot a specified image from the network (i.e. to reinstall Windows).
For security reason we do not want to use regular PXE booting from the network as we can not control the environment and PXE would open a potential attack vector.

Currently we chainload iPXE from Grub both of which are installed on the local drive. iPXE then contacts the server and gets a ipxe script file back. So far so good.

What does not work yet is to boot Windows from the second partition of the same local drive. Using
[undefined=undefined]sanboot --no-describe --drive 0x80[/undefined]
Grub loads again and we loop.

Using
[undefined=undefined]exit[/undefined]
ends up in a "No bootable device" error.

Questions:
How can I boot a specific partition from iPXE?
Is there a better way to accomplish what we are trying to do?
Is there a way to use timeouts in case the server does not answer (clients should then always boot Windows from the local drive)?

Any help and hints are highly appreciated!
Regards,
FreeMinded

(2016-02-15 11:46)MultimediaMan Wrote:  Which iPXE binary are trying to boot? You will need the lkrn or grub to boot.

(2016-02-15 10:58)FreeMinded Wrote:  What does not work yet is to boot Windows from the second partition of the same local drive. Using
sanboot --no-describe --drive 0x80
Grub loads again and we loop.

(2016-02-15 10:58)FreeMinded Wrote:  Using
exit
ends up in a "No bootable device" error.

(2016-02-15 10:58)FreeMinded Wrote:  Questions:
How can I boot a specific partition from iPXE?

(2016-02-15 10:58)FreeMinded Wrote:  Is there a better way to accomplish what we are trying to do?

(2016-02-15 10:58)FreeMinded Wrote:  Is there a way to use timeouts in case the server does not answer (clients should then always boot Windows from the local drive)?

(2016-02-15 19:18)NiKiZe Wrote:  --drive 0x80 refers to the first BIOS disk, BIOS can never boot a specific partition, it's up to the disks bootsector code to do that,

(2016-02-15 19:18)NiKiZe Wrote:  exit returns from ipxe and leaves the selection of "next boot device" to iPXEs loader (BIOS in most cases)

(2016-02-15 19:18)NiKiZe Wrote:  

(2016-02-15 10:58)FreeMinded Wrote:  Questions:
How can I boot a specific partition from iPXE?

The sanboot hack only allows to boot disks, and not booting partitions.
Simple answer is then you can't boot a specific partition from iPXE.

(2016-02-15 10:58)FreeMinded Wrote:  Is there a better way to accomplish what we are trying to do?

if you want to run the windows setup i suggest you boot it from the network with wimboot, you can still keep the install.wim on local disk if you want to, but load wimboot and boot.wim over the network.

(2016-02-15 19:18)NiKiZe Wrote:  

(2016-02-15 10:58)FreeMinded Wrote:  Is there a way to use timeouts in case the server does not answer (clients should then always boot Windows from the local drive)?

You can end ipxe script lines with || command on fail
command on fail in this case can be a goto and then exit gracefully or do the sanboot hack. You can specify a timeout for most types of fetch commands.

Hope it helps somewhat.

(2016-02-16 09:37)FreeMinded Wrote:  I'll have a deeper look at winboot. But on first sight it does not seem to do what we need

My follow-up questions now are:
1. Is there another way or hack to chainload the Windows Bootloader from iPXE?
2. Is there a way in Grub to have a different default selection if Grub is invoked for the second time (through the sanboot hack)?
3. Is there a way to hand over some variable to Grub from iPXE?

I guess this is now more a Grub than iPXE thing...

Thanks a lot for your help!

(2016-02-16 22:28)NiKiZe Wrote:  But I have to ask, why are you even entering iPXE if what you want to do is to boot from local disk anyway?