Re:Debian CD Image for AArch64 Windows Laptops
by xmodem on Wednesday December 16, 2020 @07:58AM
(#25441950)
This sounds fascinating and horrific. Where can I learn more?
Re:Debian CD Image for AArch64 Windows Laptops
by tremon on Wednesday December 16, 2020 @10:28AM
(#25443698)
Matthew Garrett wrote about this, about a decade ago. It turns out you can create an iso/usb hybrid image that boots correctly on all combinations of BIOS/UEFI, optical disc/usb drive, and PC/Mac.
Re:Debian CD Image for AArch64 Windows Laptops
by toast0 on Wednesday December 16, 2020 @01:32PM
(#25446345)
Dreamcast uses El Torito for booting as well, I bet you could make that work too. Possible issues are that I don't know if the Dreamcast will inspect multiple boot images to find an appropriately labeled one, and I don't know if the other platforms will accept a bootable disc that's prepared for Dreamcast (must have at least two sessions, first session audio, second session data with el torito for booting)
Re:Debian CD Image for AArch64 Windows Laptops
by pabs3 on Wednesday December 16, 2020 @08:51AM
(#25442434)
Re:Debian CD Image for AArch64 Windows Laptops
by flatiron on Wednesday December 16, 2020 @09:08AM
(#25442593)
https://pdos.csail.mit.edu/6.828/2014/readings/boot-cdrom.pd...
Phoenix and IBM coming up with a standard. Wonder if that was still a hard pill the swallow in 1995.
Re:Debian CD Image for AArch64 Windows Laptops
by chungus_khan on Wednesday December 16, 2020 @09:16AM
(#25442704)
Ultimately they had to if they wanted BIOS to be able to boot CD-ROMs. The BIOS boot sequence sticking around for so long is an unfortunate consequence of it becoming a decentralized standard outside of any one vendor's control, and so the only way to make it all work was for vendors to agree, and the solutions wouldn't be obvious or trivial in most cases because that boot sequence is incredibly primitive and full of assumptions coherent in a system with two floppy drives and maybe a disk if you were lucky.
But I'm sure the bad blood was measurable, especially for the higher-ups.
> To boot from a CD-ROM or DVD-ROM in the boot services environment, an EFI System partition is stored in a “no emulation” mode as defined by the “El Torito” specification.
This was chosen specifically to allow polyglot ISO files that can both be booted bh UEFI and legacy BIOS. The implementation of tools to create such polyglot files are, to say the least, interesting. The tools effectively generate both a FAT and ISO partition, each having its own file information table, but sharing the actual file contents.