Re: How interrupts work

Re: How interrupts work

[RCS]

  Thanks, but which assembler must I use for this code? GNU as? 
  I'm asking that because I am only familiar with nasm. 

  Thanks Again, 

                                  RCS 


Em Aug 2002, Dmitry Trunikov escreveu: 

>RCS wrote: 
> 
>> I need some help to understand how interrupts work on Intel. 
>> For example, how do I print a character in the screen? 
>>Wich register must contain the character for that? Is "int 10h" the 
correct 
>>interrupt for that? 
>> 
>> 
>It depends on which pc or OS you use. "int 10h" is a BIOS (base input 
>output system) interrupt i.e. it can be used AFAIK only in real CPU 
>mode. Usually for character output is used OS API. In MSDOS you can uset 
>"int 10h" or "int 21h" for input/output. Under linux you can use system 
>call "int 80h". 
>This is an example for output string under linux: 
> 
>// ssize_t write(int fd, const void *buf, size_t count); 
>// write(fileno(stdout), "hello", 6); 
> 
>.data 
>hello: 
> .string "hello world\n" 
>.text 
>.globl _start 
>_start: 
> movl 4,%eax // 4 - sys function 'write' 
> movl 1,%ebx // fd = fileno(stdio) 
> movl $hello,%ecx // buf = str 
> movl $12,%edx // count 
> int $0x80 
> 
> movl 1,%eax // sys function 'exit' 
> xorl %ebx,%ebx 
> int $0x80 
> 
>---------- 

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Re: How interrupts work

[Stephan Walter]

On Fri, 23 Aug 2002 08:30:51 -0300, RCS <cryptik@ig.com.br> wrote:

>   Thanks, but which assembler must I use for this code? GNU as? 
>   I'm asking that because I am only familiar with nasm. 

> >.data 
> >hello: 
> > .string "hello world\n" 
> >.text 
> >.globl _start 
> >_start: 
> > movl 4,%eax		// 4 - sys function 'write' 
> > movl 1,%ebx		// fd = fileno(stdio) 
> > movl $hello,%ecx	// buf = str 
> > movl $12,%edx	// count 
> > int $0x80 
> > 
> > movl 1,%eax 	// sys function 'exit' 
> > xorl %ebx,%ebx 
> > int $0x80 

This is GNU as syntax. You can use 'intel2gas' to convert from gas to
nasm and vice versa. (see
http://www.niksula.cs.hut.fi/~mtiihone/intel2gas )

Regards,
Stephan

RE: Intel2GAS (was How interrupts work)

[Jim Watters]

As I discovered two weeks ago, Intel2Gas is no longer available. I found
an older version of it's source code using a Internet cache service. But
if anyone can provide the most recent binary, I'd appreciate it.

Jim Watters


-----Original Message-----
From: Stephan Walter

This is GNU as syntax. You can use 'intel2gas' to convert from gas to
nasm and vice versa. (see
http://www.niksula.cs.hut.fi/~mtiihone/intel2gas )

Re: Intel2GAS (was How interrupts work)

[Stephan Walter]

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On Fri, 23 Aug 2002 20:46:06 -0400, "Jim Watters" <macemu@emuunlim.com>
wrote:

> 
> As I discovered two weeks ago, Intel2Gas is no longer available. I
> found an older version of it's source code using a Internet cache
> service. But if anyone can provide the most recent binary, I'd
> appreciate it.
> 

I had no problems downloading the source it from:
http://www.niksula.cs.hut.fi/~mtiihone/intel2gas/

and there's even an Debian package...

You can try the attached binary... might work if you've got the right
libs :-)

Regards,
Stephan

[-- Attachment #2: intel2gas.bz2 --]
[-- Type: application/octet-stream, Size: 9871 bytes --]

RE: Intel2GAS (was How interrupts work)

[Jim Watters]

Great! Thanks Stephan. I had spent many hours looking for this.

Jim Watters


-----Original Message-----
From: Stephan Walter

I had no problems downloading the source it from:
http://www.niksula.cs.hut.fi/~mtiihone/intel2gas/

and there's even an Debian package...

You can try the attached binary... might work if you've got the right
libs :-)

Regards,
Stephan