I am learning Assembly Language (x86) and I need to figure out how to make a register overflow using only variables rather than intermediate values.
I with to overflow the AX register by putting FFFF into a variable, moving that variable into AX, and then incrementing AX. However, I am running into problems. First off, I go to declare a WORD variable like this:
limitReg WORD 0
Then later on in .code I do this:
MOV limitReg, FFFFh
MOV ax, limitReg
However, I get the following error:
error MSB3721: The command "ml.exe /c /nologo /Zi /Fo"Debug\pa2.obj" /Fl"PA2.lst" /I "C:\Irvine" /W3 /errorReport:prompt /Ta..\..\..\..\..\..\..\Irvine\Examples\ch03\pa2.asm" exited with code 1. C:\Program Files (x86)\MSBuild\Microsoft.Cpp\v4.0\V120\BuildCustomizations\masm.targets 50
I receive no other errors. Can someone please help me out?
Here is the entire code:
INCLUDE Irvine32.inc
.data; the data segment
limitReg WORD 0
.code ; start code segment
main PROC ; start the main procedure
SUB ax, ax; zero out all registers to be used by subtracting their contents from themselves
MOV limitReg, FFFFh
MOV ax, limitReg
call DumpRegs ; dump the registers
exit
main ENDP ; end of main procedure
END main ; end of source code
Hi,
If you use MASM, hexadecimal values need to start with a number.
so FFFFH should be 0FFFFH.
Steve
here is a template for Irvine32 code
notice the paths of the files - you may need to modify them
the floatio.inc, graphwin.inc, and macros.inc files are optional
you may not need them, but it won't hurt to add them if not used
the lib files are needed
the option casemap directive forces case-sensitivity in symbol names
you can leave it out, if desired, but i don't recommend it
;###############################################################################################
INCLUDE \Masm32\Irvine\Irvine32.inc ;adds SmallWin.inc, VirtualKeys.inc
OPTION CaseMap:None
INCLUDE \Masm32\Irvine\floatio.inc
INCLUDE \Masm32\Irvine\GraphWin.inc
INCLUDE \Masm32\Irvine\macros.inc
INCLUDELIB \Masm32\Irvine\kernel32.lib
INCLUDELIB \Masm32\Irvine\user32.lib
INCLUDELIB \Masm32\Irvine\Irvine32.lib
;###############################################################################################
.DATA
szMessage db 'Hello World',13,10,0
;***********************************************************************************************
.DATA?
;###############################################################################################
.CODE
;***********************************************************************************************
main PROC
mov edx,offset szMessage
call WriteString
call WaitMsg
INVOKE ExitProcess,0
main ENDP
;###############################################################################################
END main