Homework #01 CPU Emulation and Simple OS Solution

Homework Instructions










Download and Install Vmware Player from official site.



Download and install our virtual machine from https://drive.google.com/open?id=1YppX3lNkyTsHV_lvA4w9TomNCUkpLeEg
Carefully examine 8080 cookbook and instruction set.



Use the assembler at http://sensi.org/~svo/i8080/ to develop your assembly code.



You can download the output .com file directly using this assembler.




Your homework template includes several code and sample files. Here is a description for them. Do not change Emulator Files and do not send these files with your homework. Study these files to understand the 8080 assembly code and the emulator.




8080emu.cpp : Emulator implementation for 8080. You will not change this file




8080emuCPP.h: Emulator interface for 8080. You will not change this file




Memory.h and memoryBase.h : You will not change these files

gtuos.h : sample header for GTUOS. You will rewrite this file




gtuos.cpp : sample implementation for GTUOS. You will rewrite this file




main.cpp : sample main function for this HW. You will rewrite this file




sum.asm: Adds numbers from 0 to 10 and prints the results on screen.




sum2.asm : Adds numbers from 0 to 10 and prints the results on screen using a different system call.




printstr.asm : 8080 Assembly file that prints "Hello world" on screen.

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Homework Tasks




There are two main tasks for you to do in this homework. First, you need to implement a number of GTUOS systems calls as described below




Call
Params


Function
Cycle














PRINT_B
REGISTER
A
Prints the contents of Reg B the screen as decimal.
10




=4




















PRINT_MEM
REGISTER
A
Prints the of contents of memory pointed by Reg B and C as
10




=3


decimal
















READ_B
REGISTER
A
Reads an integer from the keyboard and puts it in to Reg B
10




=7




















READ_MEM
REGISTER
A
Reads an integer from the keyboard and puts it in to address
10




=2


Reg BC
















PRINT_STR
REGISTER
A
Prints the null terminated string at the address pointed by B
10
per


=1


and C
char














READ_STR
REGISTER
A
Reads the null terminated string from the keyboard and puts it
10
per


=8


at the memory location pointed by B and C
char

















You will rewrite the two files (gtuos.h, gtuos.cpp) to implement the above system calls and you will write another file (main.cpp) to use your OS with the 8080 CPU. Use the sample main file as a guide. Do​ not touch original emulator code files.




You will also write and test the following assembly files. Use the provided sample assembly files to learn about how to use the assembler and how we call the OS.







ShowPrimes.asm: file that prints all integer from 0 to 1000 on the screen if the



number is prime than it will print “prime” next to number. Each number will be printed on a new line.




Factorize.asm: Given an integer, your code will find and show integer factors of it.



For example: factors of 20 is 1,2,4,5,10,20




Palindrome.asm: Show whether a string given from keyboard is a palindrome by



printing the “string” semicolon: “Palindrome” or “Not Palindrome” Ex:

ada: Palindrome




arthas: Not Palindrome




Expected Files: ​gtuos.h, gtuos.cpp ,main.cpp and Assembly files above



Please carefully inspect the guidelines!!
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General Homework Guidelines










No cheating, No copying, No peaking to other people homeworks



Follow the instructions very carefully.



Send required files only. Do not share your whole file system with us.



If you fail to implement one of the requirements, leave it be. Do not send an empty



file




When homework mentions about reading from keyboard it means that we are



reading from afile called “input​.txt”.




All you outputs should be written into a file called “output​.txt”​. Whenever we talk about printing to screen we are referring to writing to “output​.txt”​
Respect the file names! Our HW grading is case-sensitive.



Failing to comply any of the warnings above will result in getting a 0​ for​ your current homework.
You should use the shared virtual machine to build your code in order to achieve



consistent behavior. Since we will grade your assignments on top of this virtual machine

You can get in touch with TA for any misunderstandings or confusions about assignments.