Booting systems from ISO files by rEFInd means

[Markus Elfring]

I am used to the possibility that systems can be booted from ISO files also directly by the means of the software “GRUB 2”.
Thus I am looking for further clarification according to configuration challenges together with the rEFInd boot manager.

I have stored a few ISO files for known Linux systems in a EXT3 boot partition (and the EFI system partition).
They are configured for a simple test so that the graphical boot menu display is working as expected for rEFInd so far.
The settings need further adjustments for the desired software selection.

I would appreciate your advices.

[Roderick W. Smith]

rEFInd cannot do this except with the help of an EFI loopback driver. AFAIK, no such driver exists. If an when one becomes available, rEFInd will be able to do what you want. In the meantime, the closest alternative is to create partitions equal or greater in size to the .iso files and copy those files to those partitions using dd or a similar tool. If you then use rEFInd ISO-9660 driver, it will be able to read those partitions as if they were optical discs. Not all OSes will boot correctly in this way, but some will. It's an awkward solution compared to using .iso files directly, but it may be adequate.

[Markus Elfring]

Thanks for your information about the current software situation.

[R L]

Something like this?

https://github.com/EHfive/uefi-toys?tab=readme-ov-file

Apologies for resurrecting a thread after 4 years, but this is relevant.

[joevt]

I think an EFI loopback driver would be a super simple EFI_BLOCK_IO_PROTOCOL driver that reads from an iso file. A file system driver that already exists would do the file reading from the block IO driver. The complicated part is transitioning from EFI to Linux. I have no idea how that works in Linux (maybe there is no transition?). In macOS, a kernel extension would take over as the driver (it would need to be included in the OS or injected by the boot loader - and it would mount the file as a IOBlockStorageDevice class object).

[Markus Elfring]

Thanks for another constructive feedback.
🤔 Would any software users like to add (and support) more helpful development ideas?

[Startergo]

That would be a nice driver addition. As a workaround the easiest way is by using a USB formatted with Ventoy utility. Just drag and drop the iso image to the Ventoy USB then boot it from rEFInd.