The reason for the error is that two memory spaces cannot be exchanged directly, such as mov [di], [Si]. Register ax is required to save the following transfer values
mov ax, [si]
mov [di], ax
Error a2070: invalid instruction operations may be reported when compiling with MASM
Error condition
.WHILE CL < BUF_L
.IF BUF[CX] > MAX
MOV MAX , BUF[CX]
.ENDIF
.ENDW
Cause of occurrence
It can only be used as an address register in the stack segment for BX, BP, Si, Di BP
Solution:
Change CXin the code to BX
Using “assemble” option to patch binary files in IDA, you will receive an invalid operation error every time you enter an arithmetic instruction with calculated offset. For example:
mov [bp-4], bx Invalid operate error occurred
however
mov ax, bxsuccess. The official explanation is that the function support of modification instruction is relatively small, so it needs to be modified by other methods.
Date: 2018-7-15
1. Reference:
https://stackoverflow.com/questions/2370942/arm-assembly-print-register-value-in-decimal
2. Arm register printing
Since the ARM register print is always in hexadecimal, it seems to be a bit of a struggle. Therefore, we have been exploring the relatively convenient method of arm register printing recently, and now there are two methods for reference.
Method one:
print_decimal:
stmfd sp!, {
r4,r5,lr}
cmp r0, #0
moveq r0, #'0'
bleq putchar
beq done
mov 
.code
main proc
ret
main endp
endDirect F5 run (right-click added project), annoying error:
LNK2001: unresolved external symbol mainCRTStartup
Unparsed external symbol mainCRTStartup, which is the default entry function, will call the main function we wrote, but that is the main function inC /C++, such as void main() {return 0; }, the compiler can’t find such a main function to report the above error, so we need to specify the entry function as our own main function (in this case mian is not that main; you can change it to any other name that conforms to the identifier specification).
Right-click the project name and select the last project property
Linker -> Advanced -> The Entry Point: main name needs to be the same as in the code.
If nothing happens, you’ll be fine, but of course this code doesn’t do anything, and you won’t see anything.