Suppose I've an 3-element array in NASM
strings: dw 0x00, 0x00, 0x00
, that I want to fill with addresses of strings, also defined within the .data section, e.g.,
hello_word: db "HelloWorld!", 0.
Writing strings: dw hello_world, 0x00, 0x00 is a syntax error.
How do I populate an array with addresses, so that I can loop over it at runtime, each time incrementing the index?
Ah, "-f coff"! Make your addresses dd not dw.
this worked for me:
segment data
prompt_msg db "Input a string: ",0
output_msg db "The reverse is: ",0
stringPtr dw prompt_msg
dw output_msg
-->
0734:0100 49 6E 70 75 74 20 61 20-73 74 72 69 6E 67 3A 20 Input a string:
0734:0110 00 54 68 65 20 72 65 76-65 72 73 65 20 69 73 3A .The reverse is:
0734:0120 20 00 00 00 11
at 0x121: 00 00 and 00 11 are the two pointers to the strings
You could also load the effective addresses of the strings at runtime using the LEA instruction (x86):
lea eax, [_str1]
mov [_s_table], eax
lea eax, [_str2]
mov [_s_table + 0x04], eax
lea eax, [_str3]
mov [_s_table + 0x08], eax
But, probably, Frank Kotler's approach is better.
