Combuster wrote:
If you need to drop to real mode from a running protected mode OS your design is seriously flawed.
Maybe. But that's how I like to experiment with my OS. I did present the idea of "Restoring the hardware to original configuration" just to reckon the possible consequences of switching to Real Mode. I didn't realize that would gain me criticism as a solid feedback. Nor did I expect that someone would criticise my design.
Brynet-Inc wrote:
As for the Wiki reference, perhaps that section should be removed entirely
I don't agree. V86 has it's own place. Some emulators don't even support it. There's a reason to drop to Real Mode.
Combuster wrote:
In the case of EFI, there is no state to restore at all.
Like I asked before, "how many OSes over here are EFI-aware?"
fronty wrote:
You also say that cases where some other firmware than BIOS is used aren't related to this discussion. Where am I wrong?
You're wrong at that very point. EFI is not the theme of this discussion, so I've been avoiding this from the very beginning. EFI is a very different beast. I know it's the replacement to the legacy-BIOS but it isn't quite supported in every OS here. So, I see no reason to divert this topic to EFI.
Since EFI is becoming the more centralized issue over here, let me get this straight...
Wiki: Real Mode article wrote:
The program needs to go through the following steps:
Disable the interrupts:
Turn off maskable interrupts using CLI.
Disable NMI (optional).
Turn off paging:
Transfer control to a 1:1 page.
Ensure that the GDT and IDT are in a 1:1 page.
Clear the PG-flag in the zeroth control register.
Set the third control register to 0.
........
So, there's a step suggesting to disable paging, no? So what if an OS uses segmentation instead of paging? That step is skipped, right? I too am following similar route. I just want to add a step that suggests to restore the hardware configuration. In case someone is implementing EFI, this step could be skipped. What's wrong with that?
Combuster wrote:
So the entire point about restoring state is only about what hacks you might try to have some chance of success of implementing an "exit to DOS" option without rebooting.
Hacks?
I know it is easy to criticize people, but extremely difficult to think from the other side.
Since it seems as if some guys over here, are annoyed by this discussion, I hereby request a moderator to lock this thread. In the end, it won't really matter, so there's no reason to continue it.