Tag Archives: Debug

hello world, C and GNU as

A thing all these programs had in common was their use of the 09h function of INT 21h for printing the “hello, world!” string. But it’s time to move forward. Now I plan to use the lovely C printf function.

Posted in programming | Also tagged , , , , , , , , , , , , , , , , , , | Comments closed

Writing Programs with Echo (DOS)

How do you input those characters as parameters for the echo command? I found no way of doing that. If you know a way, please drop me a line.

Posted in programming | Also tagged , , , , , , , , , , , , , | Comments closed

Encoding Intel x86/IA-32 Assembler Instructions

Translation of the second line is a direct and solved issue. What about jmp 114? Well, we want to jump over the data (18 bytes, one byte per each character in the string.) IASDM tell us (Appendix B) that the opcode for unconditional jumps in the same segment is 11101011, which in hexadecimal, is expressed as EB.

Posted in programming | Also tagged , , , , , , , , , , , , , , , , , , | Comments closed

Debugging “hello, world”

The Go command (g) will run the program starting at the given address (in this case, CS:0100) If everything goes right, the program should output the intended “hello, world!” string, and finish with the message “Program terminated normally.”

Posted in programming | Also tagged , , , , | Comments closed