Difference between revisions of "Assembler:Commands:JMP"

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 +
[[Category:Assembler]]
 
'''command''' jmp ''size'' ''operand''
 
'''command''' jmp ''size'' ''operand''
  
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: A jump to an instruction located in a different task.
 
: A jump to an instruction located in a different task.
  
[http://x86.renejeschke.de/html/file_module_x86_id_147.html x86.renejeschke.de/html/file_module_x86_id_147.html]
+
[http://c9x.me/x86/html/file_module_x86_id_147.html c9x.me/x86/html/file_module_x86_id_147.html]
 
</div>
 
</div>
  
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  jmp long someLabel  // Jump to label with full address.
 
  jmp long someLabel  // Jump to label with full address.
  
jmp @b  // Jump back to closest label
 
 
jmp @f  // Jump forward to closest label
 
  
  
 
Running this script in 32 bit mode:
 
Running this script in 32 bit mode:
 
  globalAlloc(memTest, 0x200)
 
  globalAlloc(memTest, 0x200)
label(testLbl)
 
 
  memTest:
 
  memTest:
 
                           add [eax],al // db 00 00
 
                           add [eax],al // db 00 00
@@:
 
                          add [eax],al
 
jmp short @b
 
jmp short @f
 
                          add [eax],al
 
@@:
 
                          add [eax],al
 
 
                           add [eax],al
 
                           add [eax],al
 
  jmp short -4
 
  jmp short -4
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Running this script in 64 bit mode:
 
Running this script in 64 bit mode:
 
  globalAlloc(memTest, 0x200)
 
  globalAlloc(memTest, 0x200)
label(testLbl)
 
 
  memTest:
 
  memTest:
 
                           add [rax],al // db 00 00
 
                           add [rax],al // db 00 00
@@:
 
                          add [rax],al
 
jmp short @b
 
jmp short @f
 
                          add [rax],al
 
@@:
 
 
                           add [rax],al
 
                           add [rax],al
 
                           add [rax],al
 
                           add [rax],al
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== See also ==
+
{{AssemblerCommandSeeAlso}}
* [[Assembler]]
 
* [[Cheat_Engine:Auto Assembler|Auto Assembler]]
 
* [[Assembler:Commands|Assembler Commands]]
 
  
== External links ==
+
{{Template:AssemblerCommandExternalLinks}}
* [https://wikipedia.org/wiki/X86_instruction_listings wikipedia.org/wiki/X86_instruction_listings]
 
* [https://wikibooks.org/wiki/X86_Assembly/Other_Instructions wikibooks.org/wiki/X86_Assembly/Other_Instructions]
 
* [http://www.asmpedia.org/index.php?title=Main_Page asmpedia.org]
 

Latest revision as of 14:22, 1 September 2019

command jmp size operand

Jumps to the given operand (address).


Transfers program control to a different point in the instruction stream without recording return information. The destination (target) operand specifies the address of the instruction being jumped to. This operand can be an immediate value, a general-purpose register, or a memory location.

This instruction can be used to execute four different types of jumps:

Near jump
A jump to an instruction within the current code segment (the segment currently pointed to by the CS register), sometimes referred to as an intrasegment jump.
Short jump
A near jump where the jump range is limited to -128 to +127 from the current EIP value.
Far jump
A jump to an instruction located in a different segment than the current code segment but at the same privilege level, sometimes referred to as an intersegment jump.
Task switch
A jump to an instruction located in a different task.

c9x.me/x86/html/file_module_x86_id_147.html


Command Parameters[edit]

Parameter Description
size OPTIONAL The preferred size of the assembled address
operand The address or symbol to jump to


Examples[edit]

jmp +1A   // Jump from end of command to +1A (hex).
jmp 00123ABC   // Jump to address.
jmp 0000123456ABCDEF   // Jump to address.
jmp eax   // Jump to value of eax.
jmp rax   // Jump to value of rax.
jmp someSymbol   // Jump to user defined symbol.
jmp someLabel   // Jump to label.
jmp short someLabel   // Jump to label with short byte code.
jmp long someLabel   // Jump to label with full address.


Running this script in 32 bit mode:

globalAlloc(memTest, 0x200)
memTest:
                          add [eax],al // db 00 00
                          add [eax],al
jmp short -4
jmp short +2
                          add [eax],al
testLbl:
                          add [eax],al
jmp 02EA0002
                          add [eax],al
jmp eax
                          add [eax],al
jmp memTest
                          add [eax],al
jmp testLbl
                          add [eax],al
jmp short testLbl
                          add [eax],al
jmp long testLbl
                          add [eax],al
db 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90

Assembler.JMP.02.png


Running this script in 64 bit mode:

globalAlloc(memTest, 0x200)
memTest:
                          add [rax],al // db 00 00
                          add [rax],al
                          add [rax],al
jmp short -4
jmp short +2
                          add [rax],al
testLbl:
                          add [rax],al
jmp 01160002
                          add [rax],al
jmp rax
                          add [rax],al
jmp memTest
                          add [rax],al
jmp testLbl
                          add [rax],al
jmp short testLbl
                          add [rax],al
jmp long testLbl
                          add [rax],al
db 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90

Assembler.JMP.01.png


See also[edit]

External links[edit]