X86-jmp

• check: do long jumps and near have 4 and 2 byte offset?

"JMP" is a mnemonic used in x86 assembly language.

unconditional jump (JuMP) to the address that follows, like this:

JMP 0x89AB          ; loads IP with the new value 0x89AB
JMP 0xACDC:0x5578   ; loads CS with 0xACDC and IP with 0x5578
                    ; only works in real mode

JMP 0x56789AB1      ; loads IP with the value 0x56789AB1
                    ; only works in protected mode or unreal mode

JMP EAX             ; Jumps to the value stored in the register EAX.
                    ; only works in protected mode

There are many different forms of jumps; Relative jumps, conditional jumps, absolute jumps and register-depending jumps.

JMP $ is commonly used to hang the computer. The $ is used to refer to the same location where the instruction starts. That means that the instruction will jump to itself and thereby creating an endless loop.

See also: conditional jumps.