JUMP instruction bug I've seen for me

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Diicorp95

Joined: 18 Mar 2021
Posts: 3

Diicorp95 18 Mar 2021, 13:17

Hello, people! Do you have any idea why

Code:

jmp 0x00007E00

compiles into

Code:

jmp 0x00000200

?

I'm sure that I did everything OK. Sad

18 Mar 2021, 13:17

Diicorp95

Joined: 18 Mar 2021
Posts: 3

Diicorp95 18 Mar 2021, 13:53

I think that's because of org 0x7C00, because 0x7E00 - 0x7C00 = 0x0200...

18 Mar 2021, 13:53

revolution
When all else fails, read the source

Joined: 24 Aug 2004
Posts: 20566
Location: In your JS exploiting you and your system

revolution 18 Mar 2021, 16:20

All jmp and call instructions are IP relative when you use an immediate operand.

Everything is as expected.

18 Mar 2021, 16:20

Diicorp95

Joined: 18 Mar 2021
Posts: 3

Diicorp95 19 Mar 2021, 15:15

revolution wrote:

All jmp and call instructions are IP relative when you use an immediate operand.

Everything is as expected.

I've tested it on zero-filled IP.

19 Mar 2021, 15:15

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