Protected mode os ?
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echristian
Protected mode os ?
I am developing a os in protected mode and was wondering has anyone ever developed a protected mode os with a gui without using bios calls? MenuEt os uses bios call i think but that is the closest thing i have found so far.
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VoidLogic
RE:Protected mode os ?
You can't get at the BIOS directly from PMODE, you have to switch to real mode right? There is another way, but I can't recall. I use a extender so i'm worry free for the most part there.
-VoidLogic
-VoidLogic
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carbonBased
RE:Protected mode os ?
That's correct... you either switch back to real-mode or (more efficiently) use the processor's vm86 mode.
As per the original question, however, yes; there are pmode OSs which do not rely on the BIOS for their graphics routines.
I don't have a list, unfortunately. Linux, of course, does this; any mature OS will (no doubt with a bios failsafe mode).
For more information on how to do this, I would reccomend searching for VGADOC on google. VGADOC is a collection of APIs for many different video cards/manufacturers, and can be used in pmode.
You can also, no doubt, dissassemble the BIOS to learn how to program the VGA mode directly... however, the legality of this is questionable; the VGA standard is just that; a standard, and an open one at that. However, BIOSs are traditionally proprietary and copywrited, so... I don't know where the law stands on such a topic.
Cheers,
Jeff
As per the original question, however, yes; there are pmode OSs which do not rely on the BIOS for their graphics routines.
I don't have a list, unfortunately. Linux, of course, does this; any mature OS will (no doubt with a bios failsafe mode).
For more information on how to do this, I would reccomend searching for VGADOC on google. VGADOC is a collection of APIs for many different video cards/manufacturers, and can be used in pmode.
You can also, no doubt, dissassemble the BIOS to learn how to program the VGA mode directly... however, the legality of this is questionable; the VGA standard is just that; a standard, and an open one at that. However, BIOSs are traditionally proprietary and copywrited, so... I don't know where the law stands on such a topic.
Cheers,
Jeff
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shahzad
RE:Protected mode os ?
would u plz tell me that way or any other way to handle interrupts in pm
im sick and my time is getting finish to submit my project
how can i do it wid out switching back into real mode
more over ,are there any libraries for multithreading in real mode (coz real mode is easy)
if yes then plz do tel me the links
im sick and my time is getting finish to submit my project
how can i do it wid out switching back into real mode
more over ,are there any libraries for multithreading in real mode (coz real mode is easy)
if yes then plz do tel me the links
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Xerroz
RE:Protected mode os ?
Assuming your in Protected Mode, you can manage interrupts by setting up an IDT and by programming the PIC. Look at the intel manuals for further information, I myself am new to OS Development and havnt coded the IDT or PIC yet. Check Chapter 9 of the Intel 386 DX Microprocessor manual (most likely different than newer manuals.