Difference between revisions of "Assembler:Commands:CALL"

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(Created page with ''''command''' call ''mnemonic'' ''operand'' Calls the given operand (address or function). A RET must be hit for a CALL to work properly, best to use JMPs if unsure. === Comman…')
 
 
(12 intermediate revisions by 2 users not shown)
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'''command''' call ''mnemonic'' ''operand''
+
[[Category:Assembler]]
 +
'''command''' call ''size'' ''operand''
 +
 
 +
Calls the given operand (address or function), jumps to the given operand then returns.
 +
 
 +
Note: A RET must be hit for a CALL to work properly, best to use JMPs if unsure.
 +
 
 +
 
 +
<div style="padding:2px;border:1px dashed #2f6fab;background-color:#f4f4f4;">
 +
Saves procedure linking information on the stack and branches to the procedure (called procedure)
 +
specified with the destination (target) operand.
 +
The target operand specifies the address of the first instruction in the called procedure.
 +
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 calls:
 +
; Near call
 +
: A call to a procedure within the current code segment (the segment currently pointed to by the CS register), sometimes referred to as an intrasegment call.
 +
; Far call
 +
: A call to a procedure located in a different segment than the current code segment, sometimes referred to as an intersegment call.
 +
; Inter-privilege-level far call
 +
: A far call to a procedure in a segment at a different privilege level than that of the currently executing program or procedure.
 +
; Task switch
 +
: A call to a procedure located in a different task.
 +
 
 +
[http://c9x.me/x86/html/file_module_x86_id_26.html c9x.me/x86/html/file_module_x86_id_26.html]
 +
</div>
  
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Calls the given operand (address or function).
 
−
A RET must be hit for a CALL to work properly, best to use JMPs if unsure.
 
  
 
=== Command Parameters ===
 
=== Command Parameters ===
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!style="width: 80%;background-color:white;" align="left"|Description
 
!style="width: 80%;background-color:white;" align="left"|Description
 
|-
 
|-
−
|mnemonic '''OPTIONAL'''
+
|size '''OPTIONAL'''
 
|The preferred size of the assembled address
 
|The preferred size of the assembled address
 
|-
 
|-
 
|operand
 
|operand
−
|The address or symbol to jump to
+
|The address or symbol to call
 
|}
 
|}
  
  
 
== Examples ==
 
== Examples ==
−
  call +1A  // Jump from end of command to +1A (hex).
+
  call +1A  // Call from end of command to +1A (hex).
 +
 
 +
call 00123ABC  // Call the address.
 +
 
 +
call 0000123456ABCDEF  // Call the address.
 +
 
 +
call eax  // Call the value of eax.
  
−
  call 00123ABC   // Jump to address.
+
  call rax   // Call the value of rax.
  
−
  call 0000123456ABCDEF   // Jump to address.
+
  call someSymbol   // Call the user defined symbol.
  
−
  call eax   // Jump to value of eax.
+
  call someLabel   // Call the label.
  
−
  call rax   // Jump to value of rax.
+
  call short someLabel   // Call the label with short byte code.
  
−
  call someSymbol   // Jump to user defined symbol.
+
  call long someLabel   // Call the label with full address.
  
−
  call someLabel   // Jump to label.
+
  call @b   // Call back the closest label
  
−
  call short someLabel   // Jump to label with short byte code.
+
  call @f   // Call forward the closest label
  
−
call long someLabel  // Jump to label with full address.
 
  
−
  call @b   // Jump back to closest anonymous label (''@@:'').
+
Running this script in 32 bit mode:
 +
globalAlloc(memTest, 0x200)
 +
label(testLbl)
 +
memTest:
 +
                          add [eax],al // db 00 00
 +
@@:
 +
                          add [eax],al
 +
                          ret
 +
  call short @b
 +
call short @f
 +
                          add [eax],al
 +
@@:
 +
                          add [eax],al
 +
                          ret
 +
                          add [eax],al
 +
call short -8
 +
call short +2
 +
                          add [eax],al
 +
testLbl:
 +
                          add [eax],al
 +
                          ret
 +
call 02EA0002
 +
                          add [eax],al
 +
call eax
 +
                          add [eax],al
 +
call memTest
 +
                          add [eax],al
 +
call testLbl
 +
                          add [eax],al
 +
call short testLbl
 +
                          add [eax],al
 +
call long testLbl
 +
                          add [eax],al
 +
db 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90
  
−
call @f  // Jump forward to closest anonymous label (''@@:'').
+
[[File:Assembler.CALL.02.png]]
  
  
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                           add [rax],al
 
                           add [rax],al
 
  db 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90
 
  db 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90
−
ret
 
  
 
[[File:Assembler.CALL.01.png]]
 
[[File:Assembler.CALL.01.png]]
  
−
== 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]
 
−
* [http://www.asmpedia.org/index.php?title=Main_Page asmpedia.org]
 

Latest revision as of 15:40, 3 January 2018

command call size operand

Calls the given operand (address or function), jumps to the given operand then returns.

Note: A RET must be hit for a CALL to work properly, best to use JMPs if unsure.


Saves procedure linking information on the stack and branches to the procedure (called procedure) specified with the destination (target) operand. The target operand specifies the address of the first instruction in the called procedure. 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 calls:

Near call
A call to a procedure within the current code segment (the segment currently pointed to by the CS register), sometimes referred to as an intrasegment call.
Far call
A call to a procedure located in a different segment than the current code segment, sometimes referred to as an intersegment call.
Inter-privilege-level far call
A far call to a procedure in a segment at a different privilege level than that of the currently executing program or procedure.
Task switch
A call to a procedure located in a different task.

c9x.me/x86/html/file_module_x86_id_26.html


Command Parameters[edit]

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


Examples[edit]

call +1A   // Call from end of command to +1A (hex).

call 00123ABC   // Call the address.

call 0000123456ABCDEF   // Call the address.

call eax   // Call the value of eax.

call rax   // Call the value of rax.

call someSymbol   // Call the user defined symbol.

call someLabel   // Call the label.

call short someLabel   // Call the label with short byte code.

call long someLabel   // Call the label with full address.

call @b   // Call back the closest label

call @f   // Call forward the closest label


Running this script in 32 bit mode: 

globalAlloc(memTest, 0x200)
label(testLbl)
memTest:
                          add [eax],al // db 00 00
@@:
                          add [eax],al
                          ret
call short @b
call short @f
                          add [eax],al
@@:
                          add [eax],al
                          ret
                          add [eax],al
call short -8
call short +2
                          add [eax],al
testLbl:
                          add [eax],al
                          ret
call 02EA0002
                          add [eax],al
call eax
                          add [eax],al
call memTest
                          add [eax],al
call testLbl
                          add [eax],al
call short testLbl
                          add [eax],al
call long testLbl
                          add [eax],al
db 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90

Assembler.CALL.02.png


Running this script in 64 bit mode: 

globalAlloc(memTest, 0x200)
label(testLbl)
memTest:
                          add [rax],al // db 00 00
@@:
                          add [rax],al
                          ret
call short @b
call short @f
                          add [rax],al
@@:
                          add [rax],al
                          ret
                          add [rax],al
call short -8
call short +2
                          add [rax],al
testLbl:
                          add [rax],al
                          ret
call 01160002
                          add [rax],al
call rax
                          add [rax],al
call memTest
                          add [rax],al
call testLbl
                          add [rax],al
call short testLbl
                          add [rax],al
call long testLbl
                          add [rax],al
db 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90

Assembler.CALL.01.png

See also[edit]

External links[edit]



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