Cannot find install media on Mac Pro 2010

[crisscrosss]

Checklist

• I have searched the issue tracker and was unable to find an open or closed issue matching what I'm seeing.
• (If the issue occurs AFTER or DURING Windows 9x's hardware detection phase) I have tried to install with Skip legacy non-PnP hardware detection phase to [OFF] and the issue still occurs.
• (If the issue occurs AFTER or DURING Windows 9x's hardware detection phase) I have tried to install with the integrated driver library set to [OFF] and the issue still occurs.
• I understand that support is provided voluntarily for free, and that the author is not Microsoft and can/will probably not fix bugs in the operating system code itself. I also understand that it is impossible to support every single hardware combination out there.

What happened?

When attempting to run the installer (win98qi_v1.0.1a_ALL.iso) from a DVD on a Mac Pro 2010 it reaches the "Searching for 'iso9660' file systems in '/dev/sd*" section and hangs for quite a while, before erroring out with Cannot find install media (yet). Retrying in 2 seconds.

I have tried booting from USB however the mac doesn't seem to detect it (it can be iffy on what it wants to boot from sometimes).

I have also tried writing the CD image to a USB drive and booting from the DVD with the USB plugged in, as the system seems to be able to detect and mount USB flash drives, and while it doesn't seem to detect the USB drive on the first run, when running findcd.sh manually it seems to be able to detect the USB drive and copy files, however I'm unsure on how to progress after the shell script finishes.

Linux dmesg output

Attached is the full dmesg output
dmesg1.txt

Target Motherboard, CPU and RAM

Mac Pro (Mid-2010) (MacPro5,1)

Target GPU and Sound card(s)

ATI Radeon HD 5770

Target Storage Devices

No response

Boot method

ISO image

Reference image

Windows 98 SE Stock

Additional context

No response

[crisscrosss]

So, after more trial and error I believe the only way to get this to install on this computer is to use another computer to install it first, then swap hard drives.
The USB installer does not boot, as macs from this era can't boot MBR from USB, and cannot boot 32-bit EFI binaries.
While the Mac boots from the installer burnt to a DVD, it seems like for whatever reason the Linux environment can't find the DVD drive.

As mentioned previously, a USB drive with the installer files on it is found but only when running findcd.sh manually. After this, lunmercy can be run manually (after manually setting environment variables, for some reason findcd.sh fails to do this).

However, once in the installer, the system becomes unstable. When selecting the drive option, the installer almost always freezes for about 10 minutes, before showing the drives installed with a question mark <?> on the partition map indicator.
Sometimes, the installer will successfully show all the drives and their respective partition maps, but after selecting the drive the system shows the fdisk gui and then freezes, becoming incredibly slow and taking ~5 minutes to register key presses.

Selecting install on the lunmercy installer also takes forever to load, before erroring out with "No valid partitions were found"

Not entirely sure why the installer has this behaviour, all I can think of is that the setenv.sh script seems to fail on these lines with a directory not found error:
echo 2 >/proc/sys/vm/overcommit_memory
echo 95 >/proc/sys/vm/overcommit_ratio
Attempting to create these directories with mkdir gives the oddly contradictory error "Cannot create directory: No such file or directory"
I think this may be a permissions issue, although this is just speculation.

None of this behaviour occurs when booting the installer from a more standard PC.

[crisscrosss]

Marking this issue as closed as the best solution to this issue is likely waiting until 64-bit EFI support is added