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Allow loader to boot from a device containing an ISO image
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Authored by benno on Mar 30 2018, 11:04 PM.

Details

Summary

When booted using isoboot (see D14914) loader gets a bit confused because it can't work out where to boot from. This change teaches loader about ISO images and treats them as a partition format a-la GPT et al.

Test Plan

Boot an image using isoboot under BIOS and watch loader manage to find things like, y'know, the kernel.

Diff Detail

Repository
rS FreeBSD src repository - subversion
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Automatic diff as part of commit; lint not applicable.
Unit
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Event Timeline

I'm going to have to think about this. It seems like it's mixing up two different layers (filesystem and partition) in much the same way that ZFS is currently doing, but in a more annoying way.

Well an ISO image doesn't have a partition format per se. On top of that GPT doesn't have an established partition type for an ISO image. We could roll our own and plant it in there and go looking for that instead but it'd also imply that we had overlapping partition entries given that we're going to have the ESP entry pointing within the El Torito catalog and any ISO partition entry would be covering the entire disk including the GPT itself. I'm not sure whether that's going to make things complain or not.

This revision is now accepted and ready to land.Apr 2 2018, 1:16 AM
This revision was automatically updated to reflect the committed changes.