Submitted via IRC for TheMightyBuzzard
Or 2018 if you're brave. For now, we have a boot screen!
Story's a bit dated but being as they're in no rush, I don't see any need for us to be either. So, you lot think we'll ever actually get to play with a VMS box on cheap hardware or is this going to be another DNF situation?
Source: https://www.theregister.co.uk/2016/10/13/openvms_moves_slowly_towards_x86/
Previous coverage:
OpenVMS Not Yet Dead.
(Score: 3, Informative) by TheRaven on Thursday April 20 2017, @01:33PM (5 children)
sudo mod me up
(Score: 2) by NCommander on Thursday April 20 2017, @10:09PM (4 children)
Can you cite sources for ring 1-2 not being usable on x86_64? I googled for it but found nothing.
Also, I used to develop firmware :)
Still always moving
(Score: 0) by Anonymous Coward on Friday April 21 2017, @09:07AM (1 child)
I think parent is mistaken:
https://www.virtualbox.org/manual/ch10.html#idm9820 [virtualbox.org]
For guest code in ring 0, VirtualBox employs a nasty trick: it actually reconfigures the guest so that its ring-0 code is run in ring 1 instead (which is normally not used in x86 operating systems). As a result, when guest ring-0 code (actually running in ring 1) such as a guest device driver attempts to write to an I/O register or execute a privileged instruction, the VirtualBox hypervisor in "real" ring 0 can take over.
(Score: 2) by TheRaven on Friday April 21 2017, @01:53PM
sudo mod me up
(Score: 2) by TheRaven on Friday April 21 2017, @02:02PM (1 child)
sudo mod me up
(Score: 2) by NCommander on Friday April 21 2017, @11:59PM
Huh. I actually have found contradictory information when I went looking . Xen's security post suggests the IRET mechanism is there and the Priv spot is still present in the GDT selector. [xenproject.org]
INT/IRET on 64-bit use the 64-bit IDT format which has a spot for the code selector in the GDT you can land in, and you can still setup multiple GDT entries in place. Won't having a specific entry in the GDT at Priv 1-2, and setting the sector via IDT give you an interrupt call which would pop you into the Ring 1-2?
I may have to break out the assembler to experiment.
Still always moving