Real Time OS on MBED

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Real Time OS on MBED
Spencer Reardon and Kenneth Adams Jr. ECE 4180
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Design

• Service Calls (API)
• Threads
• Synchronization
• I/O
• Scheduler
• Drivers
• Demo Apps

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Threads

• API Calls
• task_create
• task_wait
• task_exit
• task_detach
• task_self
• sleep
• Features
• Priority designation (real time, high, normal,
  and low), range of allowable stack sizes,
  protected stacks, lower power idle mode

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Synchronization

• API Calls
• mutex_create
• mutex_lock
• mutex_unlock
• Features
• Task ownership, sleep based blocking, makes use
  of ARM atomic instruction, smart unlocking

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Memory Protection

• Implementation
• Catches access violations
• Stack overflow protection

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I/O Device Support

• Implementation
• open
• read
• write
• close
• seek
• ioctl
• Features
• Sleep tasks trying to write to full buffers
  supports pwm, GPIO, serial, filesystem

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Gantt Chart
(Planned)
(Actual)
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Demo

• SPASH (SPArtan SHell) Offers a command
  interpreter that allows a user to run various
  tasks.
• Control priorities of tasks
• Background or foreground tasks
• Various applications
• top show multiple tasks running
• audio plays audio over pwm output
• video plays video over serial connection
• crash force user mode crash by null dereference
• Debug Console Debug console shows pertinent
  information about task life cycles

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Questions?
You there, student, what is your question?