CptS460

Operating Systems and Computer Architecture | KC Wang | Spring 2021 | Washington State University

Course Goal

Design and implement a REAL embedded operating system

Resources

• Website
• Samples & Base Code
• Embedded and Real-time Operating Systems by K.C. Wang
• Design and Implementation of the MTX Operating System by K.C. Wang

Labs

1. Booter
2. LCD Driver
3. Timer and KBD Drivers
4. Midterm
5. User Mode Commands and Syscalls
6. Fork & Exec
7. Buffer Management
8. Last

Last Assignment

Objective

Develop our own User Command Program

Requirements

System Call	Function	E & RT OS
init	fork several login processes on serial ports	pg 321
login	handle login processes	pg 322
ls [filename]	list cwd or filename	pg 299
cat [filename]	display file contents or stdin to screen	-
more [filename]	display file one page/line at a time	-
grep pattern [filename]	prints each line matching the pattern	-
l2u [file1 file2]	convert lower to upper case	-
cp [file1 file2]	copy files or directories	-
sh	executable program, support I/O redirections and pipes	pg 365

Base Code

sdimage:

        /---|
            |----bin/ : All binary executables are in /bin
            |
            |---dev/ : special files tty0  c 4 0 
            |                        fd0   b 2 0 
            |                        sdc   b 3 0 
            |                        ttyS0 c 5 0
            |                        ttyS1 c 5 1
            |                        ttyS2 c 5 2   
            |---etc/ : passwd file 
            |           
            |---boot/: bootable EOS kernels
            |
            |---user/: users HOME directories

mku: script to generate a NEW user mode command from test.c and copy to /bin of sdimage

string.c: bcopy(), memcpy(), memset(), memcmp(), strcmp(), strcpy(), strlen(), strcat(), atoi(), etc

ucode.c: rest of user commands we don't have to write

uio.c: printk(char*); prints(char*), printi(int), printu(u32), printx(u32), printc(char)

Prerequisites

Ubuntu Linux version 20.04

Installation

1. Install ARM Cross Compiling packages

   sudo apt-get install gcc-arm-none-eabi
   sudo apt-get install qemu-system-arm
   

2. Clone the repository

   git clone https://github.com/k-radford/CptS460.git
   

3. Start Kernel

   cd CptS460/LAST
   ./mku test
   

4. Run a Command

   ##################### KATES's HELP MENU #####################
   #  ls       cd     pwd    cat   more    cp     mv   >   >>  #
   #  mkdir    rmdir  creat  rm    chmod   chown  lpr  <   |   #
   #############################################################
   SH 1 (input command): _
   

Demo Commands & Grading

Command	Expected Results	Observed	Weight
Boot up	P1 (init) create login processes	show 3 logins: console, ttys0, ttys1	10
login	login from tty0	user=root pass=12345, show root logged in and sh2	10
	login from ttyS0, ttyS1	show can login	5
	logout; login again	logout from console and ttys0, show another login	5
Control-C	sh must not die	on tty0 or console only	5
ls	SAME as ls -l in Linux	ls; ls /bin	10
cat	show input lines from stdin	enter keys from keyboard, cat echos	5
cat f	show contents of file f		5
cat f1 > f2; ls	show f1 and f2 SAME size		10
grep abcd	grep for abcd from stdin		5
grep printf f	show lines with "printf" ONLY		5
more f	pause after display ONE screen, Enter: advance by line, Space: advance by screen	MUST pause to let user input keys	5
cat f \ more	must PAUSE for Enter/Space	show can stop to allow user input	10
cat f \ grep printf	show lines with printf	ONE Pipe	10
cat f \ l2u \ grep PRINT	outputs all uppercase	2 pipes	20
cat < f \ cat \ grep print > out; cat out	3 PIPEs	out file created with contents	10
cp f g; ls	show f and g SAME size	Test their cp	10

Course Topics

1. Introduction to Operating Systems: Unix/Linux, MTX. computer system and operations, system development software, PC emulators, link C and assembly programs.

2. Booting OS

3. ARM Archicture, ARM programming and embedded systems

4. Processes: Concept and implementation of processes; process states, context switching, process scheduling.

5. Process management: fork, wait, exit, exec, signals, pipes in Unix/Linux and Wanix. Processes in (microKernel based) OS: Micro vs. Monnolithic Kernels, tasks, servers and user processes in Minix;

6. Process Synchronization:
   The process model; mutual exclusion and critical regions, Implementation of low-level mutual exclusion primitives. Synchronization primitives; events, event queues, semaphores.

7. Process Communication:
   High-level process synchronization constructs; messages.

8. Process Control:
   Scheduling algorithms. Dead lock and starvation problems.

9. Memory Management: Memory management schemes
   Paging and Virtual memory

10. I/O device drivers:
    Interrupts and interrupt processing Interraction between interrupt handler and process. Design and implementation of I/O drivers;

11. File Systems: Review of EXT2 file system. NFS and RFS based on UDP and TCP/IP

12. Real-time OS