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Can't boot Debian Jessie using preseed (UEFI)
2016-12-28, 20:01
Post: #2
RE: Can't boot Debian Jessie using preseed (UEFI)
Unfortunatly that documentation is not entierly correct
Quote:and we are playing with names to make sure this is easy to understand (well as easy as possible) and to explicitly tell linux which file to use. The way this works is as follows: ipxe loads debian/linux recognises it as efi stores it in memory with the command line, then loads debian/initrd.gz names it one.gz and stores it in memory, loads debian/preseed.cfg names it pressed.cfg and puts it in a cpio archive called two, then boots linux. linux loads one.gz

Note the bold text above, unfortunately it is not true that the CPIO header is added (that is only done in pcbios mode when loading a bzImage, and not yet in efi mode)

For now to fix this in efi we will need to add a cpio header ourselves beforehand to preseed.cfg, todo this we use
echo preseed.cfg | cpio -H newc -o > preseed.cfg.cpio
The echo is just to tell cpio which filename(s) it should read from.

and then update the ipxe script to use that file instead

kernel linux initrd=initrd.gz initrd=preseed.cfg.cpio
initrd initrd.gz
initrd preseed.cfg.cpio

Here we just send in our "precompiled" cpio instead of letting ipxe create it for us, this also works in legacy pcbios mode as long as we don't the second filename to the initrd line which is the trigger for creating ipxe to add the cpio header.

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RE: Can't boot Debian Jessie using preseed (UEFI) - NiKiZe - 2016-12-28 20:01

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