Description
Purpose:
Become familiar with the tool chain → the assembler, linker, and debugger. Refresh concepts regarding data representation including binary, decimal, and hex. Display values in memory for integers, reals, and characters. Points: 25
Assignment:
Part A: Write a simple assembly language program to compute the following formulas: bAns1 = bVar1 + bVar2 bAns2 = bVar1 – bVar2 wAns1 = wVar1 + wVar2 wAns2 = wVar1 – wVar2 dAns1 = dVar1 + dVar2 dAns2 = dVar1 – dVar2 Declare the following variables in the data segment (after the “.data”). bVar1 db 37 bVar2 db 51 bAns1 db 0 bAns2 db 0 wVar1 dw 2654 wVar2 dw 1873 wAns1 dw 0 wAns2 dw 0 dVar1 dd 164126937 dVar2 dd 102512521 dVar3 dd -15476 dAns1 dd 0 dAns2 dd 0 qVar1 dq 123456789112 flt1 dd -15.125 flt2 dd 11.25 tao dd 2.71828 myClass db “CS-218”, NULL saying db “May the force be with you.”, NULL myName db “your name goes here”, NULL Be sure to replace the “your name goes here” with your actual name (in quotes). Fail to replace your name will result in a 20% penalty.
Part B: Complete the Assignment #2 – Data Representation Worksheet on the class web page. The assignment #2 worksheet answers on available from the debugger. Note, the data representation worksheet will not be accepted late. Submission: • All source files must assemble and execute on Ubuntu with yasm. • Submit source files ◦ Submit a copy of the program source file via the on-line
submission • Once you submit, the system will score the project and provide feedback. ◦ If you do not get full score, you can (and should) correct and resubmit. ◦ You can re-submit an unlimited number of times before the due date/time. • Late submissions will be accepted for a period of 24 hours after the due date/time for any given assignment.
Late submissions will be subject to a ~2% reduction in points per an hour late. If you submit 1 minute – 1 hour late -2%, 1-2 hours late -4%, … , 23-24 hours late -50%. This means after 24 hours late submissions will receive an automatic 0.
Program Header Block
All source files must include your name, section number, assignment, NSHE number, and program description. The required format is as follows: ; Name: ; NSHE_ID: ; Section: <4-digit-section> ; Assignment: ; Description: Failure to include your name in this format will result in a loss of up to 20%. Scoring Rubric Scoring will include functionality, code quality, and documentation. Below is a summary of the scoring rubric for this assignment. Criteria Weight Summary Assemble – Failure to assemble will result in a score of 0. Program Header 20% Must include header block in the required format (see above). General Comments 20% Must include an appropriate level of program documentation. Program Functionality (and on-time) 60% Program must meet the functional requirements as outlined in the assignment. Must be submitted on time for full score.
Debugger Commands:
Execute the program in the debugger (in the same manner as assignment #1). You should review the DDD/GDB debugger information handout to understand the debugger commands examine memory variables. You may use the provided “a2in.txt” to display the variables with the debugger. • Each byte, word, double-word sized, and quad-word variable is displayed twice (once in decimal and again in hex). • The floating point values are display twice (once as a real value and again in hex). • The strings are displayed twice, once showing both the decimal and ASCII values and then just the hex values for the first six characters A brief summary of the command to examine memory is as follows: x/ & Examine memory location number of locations to display, 1 is default. format: d – decimal x – hex t – binary u – unsigned c – character s – string t – binary f – floating point unit size: b – byte (8-bits) h – halfword (16-bits) w – word (32-bits) g – giant (64-bits) For example, to display the 16-bit variable wVar2 and the 32-bit variable dVar1, the commands would be as follows: x/dh &wVar2 x/dw &dVar1 x/dg &qVar1 For future assignments you will need to select the correct command to display the data based on the defined size and any guidance from the assignment.
