Real mode -> PMode -> V86

[inflater]

Well, I can't give up the interrupts and i don't want the 64 KB limit for my OS. I read the FAQ that v8086 may be helpful. OK, I'm now successfully in protected mode, and i have somewhere readed, that i must switch TSS to get in V86 mode (and hook my kernel to address bigger than 0xC000000 if it is below 1 MB). Anyone please know how?

inflater

[Combuster]

IIRC switching TSSes isn't the only way to enter v8086 mode, but if thats how you want to do it, a far jump (or interrupt) to a TSS selector is enough.

In any case, read the intel manuals

[JAAman]

Well, I can't give up the interrupts and i don't want the 64 KB limit for my OS. I read the FAQ that v8086 may be helpful. OK, I'm now successfully in protected mode, and i have somewhere readed, that i must switch TSS to get in V86 mode (and hook my kernel to address bigger than 0xC000000 if it is below 1 MB). Anyone please know how?

inflater

yes, iirc, you need a TSS to use VMode, but you will also need one to support any lower privileged code segments

first, do you have the intel manuals? that is not only the official documentation, but also the best and most acurate (if you dont have them, there is a link in my signature -- at the bottom of the page there is a link to order hard-copies -- deffinately recommended, and its free including shipping, get all 5 books, though 3a will be the most important)

in the intel manuals, read chapter 15 (in volume 3a -- particularly 15.2 for the basics) for complete discription and more information about initialization and use of VMode, you will probably also want to use the VMode extensions, to allow it to process its own ints and I/O if you want to use it extensively for BIOS calls (though i would transition to PMode drivers as quickly as possible as there is significant performance penalty for using the BIOS drivers -- esp with multi-tasking)

for information about the TSS, look in section 6.2


if you have any more specific questions just ask -- though i dont have much experience with VMode, ill help where i can and im sure others will too