Re: Generating Interrupt 10h (switching from protected mode to real mode)

Re: Generating Interrupt 10h (switching from protected mode to real mode)

[Stas Sergeev]

Hello.

Vishal Soni wrote:
> like i am doing below in my sample driver for linux.
[]
> Could anyone please
> brief me the steps or the sample code or any pointers to do the
> same.i.e how do we save processor context and then achieve the same by
> vm86() system call.
Sample of the kernel driver:
http://dev.gentoo.org/~spock/projects/vesafb-tng/archive/vesafb-tng-1.0-rc1-r3-2.6.15-rc1.patch

Userspace interface:
http://sourceforge.net/projects/lrmi

hth.

ps: this list is about a dosemu, the user-space PC/DOS emulator, not
about the vm86 usage in general.

Re: Illegal user

[Stas Sergeev]

Hello.

Brian Hancock wrote:
> When I execute dosemu I get an "Illegal user" message...
> Does anyone have an ideas about how to rectify this?
See here:
http://sourceforge.net/tracker/?group_id=49784&atid=457448&func=detail&aid=1117902

Generating Interrupt 10h (switching from protected mode to real mode)

[Vishal Soni]

Hello,

I need to understand BIOS Function Calls specifically INT 10H BIOS
interrupt, which i can generate by switching from protected mode to
real mode.

like i am doing below in my sample driver for linux.
asm("mov $13h, %AX");
asm("INT 10h);
But this was giving me floating point exception while doing insmod.

I did more research on this and realised that i need to switch from
Protected mode
to real mode or else real mode interrupt handler, would be replaced
with an appropriate exception handler by Linux. Could anyone please
brief me the steps or the sample code or any pointers to do the
same.i.e how do we save processor context and then achieve the same by
vm86() system call.

Your help would be highly appreciated.
thank you,
Vishal.