Implementing Simple Realtime Systems

1
Implementing Simple Realtime Systems

• Chapter 2

2
Topics

• Multi-tasking
• Simple task loop with interrupts
• XINU system details
• How to work on Project 1?

3
Multi-tasking

• Execute the command to how many processes you
  operating system is currently processing
• gt ps A wc -l

4
Simple Task Loops
isr1
isr2
isr3
Undependable response time Esp. with interrupts
5
Simple IO

• Simple IO program to access the parallel port
• Observe the use of time library for delays.
• In our project 1 you will access the LEDs on the
  board using GPIO General purpose IO, register of
  1 bit per LED
• Simple stepper motor observe that the code is
  table-driven

6
XINU on WRT54GL System

• Lets analyze the code, various components, the
  memory layout
• The XINU kernel

7
Memory Layout

• Lets look at XINU/ WRT54GL layout in the handout
  enclosed.
• Memory layout
• Also see the Nexos lab handout