Error in switching from protected mode to real mode in Fedora

[East]

hi all

I dont know whether it is right place to post this post. If it is not please redirect to right place.

I want to use int 19h from my linux application. As far as searched from web, from protected mode i can't use the BIOS interrupts, otherwise i should write up an new OS from scratch. I am trying for mode switching like protected mode to real mode. For that i got some pages from google,
Transition from Protected Mode to Real Mode

I dont understand anything from this. Can anyone help me regarding the mode switching....
Thanks in advance

[wje_lf]

from protected mode i can't use the BIOS interrupts, otherwise i should write up an new OS from scratch.

That pretty much sums it up. In a Linux user application, you just don't do this.

[East]

Thanks for the reply. Actually i want to boot up the system with OS loaded in second partition when i clicked a button from my linux application using int 19h. It cant be done in protected mode. Now i want to switch from protected mode to real mode.

If i am going to use int 19h in real mode, how can i use?

[wje_lf]

If i am going to use int 19h in real mode, how can i use?

By not doing it in a Linux application at all, if I understand your question correctly. This sounds snippy, but I think it's the truth.

Sorry.

[East]

Thanks for the reply.
how an user (or) programmer can make use of int 19h in real mode?
Can anyone help me.

[wje_lf]

The only way to do so in Linux is not to do it in an application. The easiest way is to do it in a device driver. You can get information on writing Linux device drivers by googling this:

write Linux "device driver"

I apologize for waiting so long to say that, but somehow I kept the idea in my head that you needed to do this in an application.

Anyway, hope this helps.

[East]

I have seen in the google that DPMI allows DOS programs can be executed in protected mode. Can anyone explain me about how can i make use of the DPMI.
Thanks in advance.

[wje_lf]

DPMI? Under Linux? Here you go.

[East]

Thanks wje_lf!!
I have installed DosBox in my system and executed some of example programs.In the link Int 2FH Function 1686H , they have specified to get the CPU mode of the system. Now i am trying to write as C appln, in that i will "AX" register. But the problem is how to complie and all , Borland C complier.... any more help on this


I have installed DosBox in window Xp

[wje_lf]

If you're running the compiler in DosBox, you're working not in the Linux world, but in the Microsoft world. I'm guessing that unless there's a lurker out there who can help with this question, you're more likely to get better answers in a Microsoft forum of some sort.

I wish I could help more.