tailieunhanh - Cracker Handbook 1.0 part 41

Tham khảo tài liệu 'cracker handbook part 41', công nghệ thông tin, kỹ thuật lập trình phục vụ nhu cầu học tập, nghiên cứu và làm việc hiệu quả | -n The rcx command allows us to change the content of the CX register to the value we obtained from the size of the file with h in this case 000a since the result of the subtraction of the final address from the initial address. -rcx CX 0000 000a Lastly the w command writes our program on the disk indicating how many bytes it wrote. -w Writing 000A bytes To save an already loaded file two steps are necessary Give the name of the file to be loaded. Load it using the l load command. To obtain the correct result of the following steps it is necessary that the above program be already created. Inside Debug we write the following -n -l -u 100 109 0C3D 0100 B80200 MOV AX 0002 0C3D 0103 BB0400 MOV BX 0004 0C3D 0106 01D8 ADD AX BX 0C3D 0108 CD20 INT 20 The last u command is used to verify that the program was loaded on memory. What it does is that it disassembles the code and shows it disassembled. The parameters indicate to Debug from where and to where to disassemble. Debug always loads the programs on memory on the address 100H otherwise indicated. 3 Assembler programming Table of Contents Building Assembler programs Assembly process More assembler programs Types of instructions Click here to get more assembler programs Building Assembler programs Needed software Assembler Programming Needed software In order to be able to create a program several tools are needed First an editor to create the source program. Second a compiler which is nothing more than a program that translates the source program into an object program. And third a linker that generates the executable program from the object program. The editor can be any text editor at hand and as a compiler we will use the TASM macro assembler from Borland and as a linker we will use the Tlink program. The extension used so that TASM recognizes the source programs in assembler is .ASM once translated the source program the TASM creates a file with the .OBJ .