.COM executable

[Ycep]

I'm 100% sure I'm not running in user mode.
Starting to get headache from this...
Whoops, sorry, I'm telling you wrong:
This works

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CLI
HLT

This works too:

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x:
nop
jmp x

But this does not (releases GPF):

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lea ebx, [str1]
mov eax, 2
int 0x5F
ret
str1: db "This is a test.",0x00

[Kevin]

Then I guess you don't have a valid handler for interrupt 0x5f.

[SpyderTL]

Try removing this line first:

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lea ebx, [str1]

Then try replacing that line, and removing this line:

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int 0x5F

Then try replacing the "ret" at the end with a x: jmp x line like your other code.

These are the only three lines that could possibly cause a GPF. (I believe)

This should tell you which of these three lines is causing the problem, and give you a hint how to fix it.

My guess is that the code is not being loaded to the memory location that you think it is, or this code is being jumped to instead of called, meaning your "ret" instruction is returning to "nowhere".

[Ycep]

Hurray! I fixed it! It works!
Thanks to everybody who helped me.

The problem was in my system calls interrupt. It's fixed now!

[trolly]

you need to do relocation, or write a Position independent code in the com executable