XV6 'ps' System Call Implementation - Detailed Overview

Introduction

🌐 Welcome to the comprehensive documentation of the 'ps' system call enhancement for the XV6 operating system, a project developed as part of the Operating Systems course at the Open University of Israel. This document aims to strike a balance between professional detail and engaging presentation.

Implementation Overview

Files and Modifications

1. ps.c: The user-space interface 🚀. A straightforward, command-line gateway to our new system call.

2. user.h: Updated with cps192 system call prototype 📝, bridging user commands to kernel operations.

3. proc.c: Core implementation of cps192 🧠. This is where the process table gets translated into valuable insights.

4. sysproc.c: The kernel's gatekeeper 🛡️. Validates and processes the cps192 system call from user space.

5. Usys.S: Assembly instructions, tailored to smoothly handle our new system call 🎩. The syscall number 192 is a key player here.

6. syscall.c: Integrating our star, the cps192, into the grand system call dispatch table 🌟.

7. defs.h: Contains the formal declaration of cps192 🔍, ensuring internal kernel components recognize our new addition.

Execution Flow

• User-Space Invocation: Triggered by ps, this simple yet powerful command unravels the curtain to reveal the state of system processes.

• Kernel-Level Execution: sysproc.c and proc.c work in tandem, validating and executing the system call, thereby turning data into information.

Usage Guidelines

Invoke the ps command in the XV6 shell to access real-time process information, a crucial tool for system introspection and debugging.

Testing & Compliance

• Assigned syscall number 192, meticulously chosen to avoid any conflicts and ensure seamless integration.

• Rigorous tests and validations were conducted to affirm functionality, security, and stability, ensuring top-notch performance.

Reflections and Achievements

Despite a small setback due to a delay in handling (resulting in a 98/100 score), the project stands as a testament to the fusion of academic rigor and practical system programming skills.

Conclusion

The addition of the 'ps' system call is more than just a feature; it's a bridge connecting theoretical knowledge with real-world system operation, crafted with care for the aspiring minds at the Open University of Israel. Here's to many more cycles of learning and innovation! 🎓💡