Reflections on Fall Semester 2022

This fall semester of 2022 was a memorable one for me. I put my full focus into classes such as System Programming, Digital Systems Design and Experiments, and Internet Security and was able to achieve great results. In this post, I want to take an overview of what I have learned in each subject and record my experiences during this semester.

System Programming

In System Programming, I learned about the general overview of computer systems by reading CS:APP. Through this class, I studied the following topics:

• Machine-Level Programming
  • Assembly Basics
  • x86-64 Linux Memory Layout & How program uses stack for calling procedures
  • Buffer Overflow Attack and Mitigations for the attack (Stack Canary, ASLR, NX, …)
  • Assignments: bomblab(Reverse Engineering using gdb) & attacklab(Exploiting programs using BOF)
• Basics of Compiler Optimization (Constant Folding, Loop Unrolling, Code Motion…)
• Memory Hierarchy
• Linking
  • ELF object files
  • Loading Executable Object Files
  • Static Linking & Dynamic Linking
  • Position-Independent Code (PIC)
• Exceptional Control Flow
  • Exception & Exception handler, Signals
  • Process Control (fork, wait, exec, …)
  • Assignments: shlab(Wrote my own Unix shell), dbglab(Wrote my own debugger with breakpoint feature)
• Virtual Memory
  • Overview of Virtual Memory
  • Dynamic Memory Allocation
  • Assignment: malloclab(Wrote my own memory allocator using segregated free lists)
• System Level I/O, File System
• Network Programming
• Concurrent Programming
  • Multithreading, Semaphore, Mutex
  • Race, Deadlock, Livelock, Starvation
  • Thread-safe & Async-signal-safe
  • Assignment: proxylab(Wrote my own web proxy)

Digital Systems Design and Experiments

In Digital Systems Design and Experiments, I learned Verilog to design a practical digital system, and various digital modules such as Adders, Multipliers, Counters. Through this class, I learned following topics:

• Verilog
• Designing Digital Systems
  • ASICs, FPGAs, …
  • Static Timing Analysis
• Number Representations
  • 1’s Complement, 2’s Complement, RNS, MRS, …
  • Floating-Point Arithmetic
• Adders
  • RCA, CLA, Carry Select Adder, Carry Skip Adder, Carry Save Adder, Parallel Counters, …
• Multiplication
  • Booth’s Algorithm
• Labs & Term Project - Implementing a CNN Accelerator
  • Term project was to implement a CNN Accelerator using Systolic Array on the FPGA board in team.
  • I designed a pooling module that performs the computation in pooling layer in CNN, and modules that uses APB protocol to communicate with host CPU from FPGA board.
  • I also participated in debugging a FC module and Conv module.
  • Although our every modules did success to pass the simulation test, we couldn’t upload the program on FPGA board, because of the error in Conv module. 🥲 (Pooling module & FC module worked well when uploaded on the board.)

Internet Security

In Internet Security, I learned various topics about internet security such as Cryptography, Blockchain, Web security.

• Cryptography
  • Symmetric key cryptography
  • Public key cryptography - RSA, ElGamal algorithm, ECC…
  • Digital Signatures, MAC
• PKI (Public Key Infrastructure)
• Blockchain
• Web & Network Security
  • TCP/IP Architecture, HTTPS
  • DDoS Attacks
  • Firewall, IDS
  • Cookie, SQL Injection, XSS, CSRF

Conclusion

Overall, I am very pleased with the results I have achieved this semester. My hard work has paid off, and I have earned an A+ in all of the classes I took this semester. 😊

My fall semester of 2022 was a fruitful one that allowed me to gain insight and knowledge in a variety of different topics. Through the classes I took, I was able to learn about computer systems, digital systems design, internet security, and more. I am grateful for the experience I had and look forward to continuing to learn and grow.