1 / 15

CSCI 2510 Tutorial 3 A “Tutorial3_x86Basics” Program in Assembly Language

CSCI 2510 Tutorial 3 A “Tutorial3_x86Basics” Program in Assembly Language. ZONG Wen Department of Computer Science and Engineering The Chinese University of Hong Kong wzong@cse.cuhk.edu.hk. Main topic:. 1, IA-32 Manuals 2, Tutorial3_x86Basics 3, Assembly Language Syntax

burian
Download Presentation

CSCI 2510 Tutorial 3 A “Tutorial3_x86Basics” Program in Assembly Language

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. CSCI 2510 Tutorial 3A “Tutorial3_x86Basics” Program in Assembly Language ZONG Wen Department of Computer Science and Engineering The Chinese University of Hong Kongwzong@cse.cuhk.edu.hk

  2. Main topic: 1, IA-32 Manuals 2, Tutorial3_x86Basics 3, Assembly Language Syntax 4, Related links and exercises

  3. IA-32Manuals • Volume 1: Basic Architecture • Volume 2A: Instruction Set Reference, A-M • Volume 2B: Instruction Set Reference, N-Z

  4. Tutorial3_x86Basics • Download Tutorial3_x86Basics.zip • http://www.cse.cuhk.edu.hk/csci2510

  5. Tutorial3_x86Basics • Extract Tutorial3_x86Basics.zip • Open Tutorial3_x86Basics.sln (Visual Studio Solution file) in Visual C++ 2008 • Press F7 to Build Solution (assemble) • Antivirus software may need to be temporarily shutdown to avoid false alarm • Add a Break Point . Press F10 to Start Debugging • Right click onEditor Window (assembly code,) click “Go to Disassembly”

  6. Tutorial3_x86Basics • View the values of variables in Registers, Memory 1 and Watch windows.(in Debug->Window)

  7. AssemblyLanguageSyntax • .686 • Target processor. Use instructions for Pentium class machines. • .MODEL FLAT, StdCall • Use the flat memory model. Use Standard calling conventions. • .DATA • Create a near data segment. Local variables are declared after this directive. • .CODE • Indicates the start of a code segment.

  8. AssemblyLanguageSyntax • option casemap:none • Case sensitive to avoid messing up function names. • include include\msvcrt.inc • includeliblib\msvcrt.lib • Include external library function definitions. • MicroSoftVisual C RunTime

  9. AssemblyLanguageSyntax • ; comment line • main PROC ; begin of procedure • label1: ; define an address label • jmp label1 ; jump to label1, i.e., infinite loop! • main ENDP ; end of procedure • times2 PROC ; begin of procedure • shl eax, 1 ; shift left by 1 bit, i.e., multiply by 2 in binary! • ret ; return • times2 ENDP ; end of procedure • END times2 ;end of this assembly file AND define entry point

  10. AssemblyLanguageSyntax • DB, DW, DWORD, DQ • Define 1-byte, 2-byte, 4-byte, 8-byte data items. • Intel uses little-endian, i.e. the least significant byte of a word is stored at its lowest address. • Examples: • SINGLEBYTE DB12h • TWOBYTEDW1234h • FOURBYTE DWORD12345678h • EIGHTBYTE DQ123456789abcdef0h

  11. AssemblyLanguageSyntax • Use DB to define a string, ended with 0 (null terminator) • HELLODB"Hello world!", 0 • FORMATDB"ebx = %d (base 10)", 10, 0 • ASCII code of new-line is 10, \n is NOT supported! • SIXBYTE DB6 DUP(99h) • Define 6 bytes, with 99h as the content of each byte • n DUP(X) means duplicate X n times • PI EQU 3.14159 • MYREG EQU eax • Symbolic constants for MASM substitution

  12. AssemblyLanguageSyntax

  13. AssemblyLanguageSyntax • moveax, 0a34abcdfh;eax = 0a34abcdfh • xoreax, eax ;eax = 0 • addMYREG, ebx ;eax = eax + ebx • Refer to x86Basic.asm for more details and examples.

  14. Relatedlink • Intel® 64 and IA-32 Architectures Software Developer's Manuals: • http://www.intel.com/products/processor/manuals/

  15. Exercises • Define two 32-bit integers in data segment, compute their average (floored to integer), and use crt_printf() to output the result. • Try to use crt_scanf() to read a 32-bit integer from user, multiply it by 2, and output the result.

More Related