Rich:
You are booting UEFI using CSM base video drivers:
SET VIO_SVGA=DEVICE(BVHVGA,BVHSVGA)
vs.
SET VIO_SVGA=DEVICE(BVHEFI)
This turned out to be the magic info I needed.
If
SET VIO_SVGA=DEVICE(BVHVGA,BVHSVGA)
and I boot CSM then SNAP works correctly and I don't get the weird triangles durning boot.
If
SET VIO_SVGA=DEVICE(BVHEFI)
and I boot UEFI I also don't get the weird triangles but DOS sessions do not work.
Dave:
I have given up booting directly, CSM mode, to AOS. I have to press F11 on startup and select the drive from the menu.
I did try reFind (eEFInd), and used SCANFOR and UEFI_DEEP_LEGACY_SCAN options in refind.conf. reFind will find the hard drive and will boot to it in CSM mode, but it requires an additional boot. The sequence is :
1) initial boot goes to reFind menu
2) on reFind menu select hard drive, press enter
3) refind reboots the machine and this reboot goes directly into the drive I selected.
So I am pleased and impressed that reFind will boot to a drive in CSM mode, which its documentation says it won't do.
But since that requires an additional reboot (albeit automated), what's the point.
The good news is once I am in AOS and reboot the enhanced shutdown dialog lists the boot volume and selecting that allows a reboot to go directly into AOS.
So I am stuck with F11 on initial boot and reset. Still worth it to get SNAP working.
Thanks again everyone for your help and suggestions. I really appreciate it.
[edit/modify]
Correction - turns out I can boot directly to a MBR disk in CSM mode on initial boot. Just had to move the hard drive to a different SATA socket (lower SATA number, i.e. from SATA 7 to SATA 1). This then allows the drive to appear as an available drive in the boot priority list. Putting it as the first drive in the priority list has it booting correctly.
[end edit modify]