Well, here's the issue:
VirtualBox 4.3.6 runs OS X 10.5.8 just fine.
My 2015 MBP however, runs OS X 10.11, which is incompatible with 4.3.6 -- it needs 5.something.
Furthermore, the MBP uses the CrystalWell architecture, which 10.5 doesn't recognize.
So, I've done the following:
1. remove /System/Library/Extensions/AppleIntelCPUPowerManagement.kext
VBoxManage modifyvm "<vmname>" --cpuidset 00000001 000006f6 00000800 80000209 078bfbff
-- to set the CPU to a recognized one instead of CrystalWell
VBoxManage setextradata "<vmname>" VBoxInternal/Devices/efi/0/Config/DmiSystemProduct "MacBookPro2,1"
-- to set the machine ID to a recognized one instead of MacBookPro11,2 or whatever my current one is.
4. Play with theh 32/64-bit settings -- some versions of 4.3 will run 10.5 in 32-bit, some will run it in 64-bit
5. Set memory to 1024 MBs -- it sometimes behaves oddly with more memory
So: if I use an already installed image from when I had an older computer and 4.3.6, I get:
I saw from that that I had modified the IOACPI kernel to attempt to use a newer one, so I tried to use an older version of the kext...
So; moving back to original install media, when I attempt to boot from that I get:
Anyone have any idea how I could move forward here? The kernel patch for 10.4 doesn't work for 10.5, and supposedly isn't needed (the one where the cpuid actually is missing some info in newer architectures that it uses to set things up).
I've spent almost a year wrestling with this now, and am at a loss. I've had some advice saying things like "it works for me" and similar, but nothing's working in my case.
Anyone have ideas on what else I can try to get 10.5 running again?