2003-01-21 18:33:00

by Electroniks New

[permalink] [raw]
Subject: Bios interrupts

Hi,
1) i don't exactly understand the ports (Bios data).
I also understand that linux does override the bios
functions so that more functionality is acheived.

2) Can you send the standard ports for use and i may
later use inb and
oub on those ports for data exchange.

3) Also what does jmp short $+2 instruction do ?How
can i change it into AT&T syntax or inline assembly
? Also what does instruction "in al,64h" do .
I found these on the net.They are dos code i
assume. Is "in" same as mov .
If not how do they differ ? The article was named
Enabling the A20 line.
(never mind the article).
It somewhere says enable .
Any idea where can i change into AT&T syntax.It is
in Intel syntax.
Any idea of sleep instruction in assembly. I tried
but couldn't find .
I tried a couple of jmps but it never slows down
.How to make the pc sleep
(asm instruction for sleep (CPU idle).I put 16000
jmps loops but didn't
slow down a bit .

4) If possible please explain how to use keyboard in
a similar manner.
(If time permits then simple mouse code).

5)I don't understand the keyboard interrupts 0x64 ,
mouse 0x33 and in some
sites i see the keyboard controllers as 0x64
where as in some sites the
code contains 0x10.So what should i use in my
program.

6) Is there any documentation for these ports to
read and write data.


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2003-01-21 18:49:26

by Richard B. Johnson

[permalink] [raw]
Subject: Re: Bios interrupts

On Tue, 21 Jan 2003, Electroniks New wrote:

> Hi,
> 1) i don't exactly understand the ports (Bios data).
> I also understand that linux does override the bios
> functions so that more functionality is acheived.
>
> 2) Can you send the standard ports for use and i may
> later use inb and
> oub on those ports for data exchange.
>
> 3) Also what does jmp short $+2 instruction do ?How
> can i change it into AT&T syntax or inline assembly
> ? Also what does instruction "in al,64h" do .
> I found these on the net.They are dos code i
> assume. Is "in" same as mov .
[SNIPPED...]

Linux is an operating system that does all that stuff for you.
In fact, it prevents user code from touching hardware ar all.
If you learn the Unix/Posix stuff, you will never have to play
with assembly language again.

Linux operates all of the standard PC hardware in a standard
way that allows programs to use open()/close()/read()/write()/
and ioctl() to "talk" to hardware in a standard high-efficiency
way. If you have additional hardware that Linux doesn't "know"
about, then you can write a device-driver (module) for it.

Cheers,
Dick Johnson
Penguin : Linux version 2.4.18 on an i686 machine (797.90 BogoMips).
Why is the government concerned about the lunatic fringe? Think about it.