Schedule

Readings:

• A fun read on how the Raspberry Pi came to be for a taste of the adventure to come.
• For background, review our guides on electricity, binary/hexadecimal numbers, and the unix command line.
• Bookmark this collection of unix video tutorials that were prepared for CS107 students. These videos cover basic concepts, common utilities, development tools, and productivity features.
• I also recommend Steven Wolfram's blog post Untangling the Tale of Ada Lovelace for a nice description of Charles Babbage's and Lady Ada Lovelace's roles in developing the concept of a general-purpose computer.

• Read Baking Pi ( intro, lesson1, lesson2 ) and skim Carl Burch's Intro to ARM assembly.
• Here is a link to the VisUAL simulator demoed in lecture.

• Before lecture, read/skim sections A3.1-A3.4 and A3.11 from the ARM Instruction Set Architecture manual.
• Our one-page guide to ARM.
• An interactive demo of ARM immediate value encoding. A tribute to how much can be done with just an 8-bit value and barrel shifter!
• Enjoy Danny Cohen's article Holy Wars and a Plea for Peace on the history of little-endian vs. big-endian.

• Review sections A3.2 and A3.3 on conditional execution and branch instructions from the ARM Instruction Set manual
• Our one-page guide to ARM.
• Brush up on C basics (syntax, data types, operators, control structures) via your favorite C reference; sections 1-2 of Nick Parlante's EssentialC; or chapters 1, 2, and 3 of K&R. Skip content on I/O and standard libraries (we are bare metal!)
• Read Dennis Ritchie's account of the history of C
• Try out the Compiler Explorer demoed in lecture
• Read our guides on make and gcc

• Before lecture, read EssentialC chapters 3 (skip material on structures) and 6 (skip material on the heap and memory management) or K&R 5.1-5.4. C-strings are primitive compared to Java/C++ strings; take note of the manual effort required to use and pitfalls to avoid.
• C volatile can be subtle and tricky. See GeeksForGeeks advice on correct use and John Regehr's blog on what NOT to do with volatile

• Read up on C functions (Chapter 4 in K&R, or Section 4 in Essential C).
• Read Thinking Geek's explanation of the mechanics of local variables and stack frames.
• Here is the ARM reference on implementing stacks with ldm and stm and this nice explanation of LDM https://keleshev.com/ldm-my-favorite-arm-instruction/

• Read about characters and strings, IO functions (putc,puts,printf), and structures (Sections 1.5, 1.6, 1.9, 5.5, 6, 7 in K&R; or Section 3 in EssentialC).
• Poul-Henning Kamp's essay on The Most Expensive One-byte Mistake. Did Ken, Dennis, and Brian choose wrong with NUL-terminated text strings?
• Read Sparkfun's tutorial on serial communication.

• Read David Welch's articles on baremetal programming and bss data.

• Read our overview of ARM stack frames
• Review dynamic memory allocation (malloc/free in C) and the operation of the heap (K&R 5.6-5.9 or Essential C Section 6). Consider the comparison/contrast between stack and heap allocation and use cases for each.

We've crossed the halfway point! We will use this lecture to catch-up/expand on lecture content covered lightly on first pass, and discuss how to further your mastery of C.

Readings:

• Google style guide for C/C++ code: https://google.github.io/styleguide/cppguide.html
• Read code! Our code, your code, other published code,… Some selected projects to browse:
  • https://github.com/dwelch67/raspberrypi, David Welch baremetal examples
  • https://opensource.apple.com, Apple OpenSource
  • https://directory.fsf.org/wiki/GNU, Free Software Foundation (GNU)
  • https://musl.libc.org, Musl C library
• The masters share their best practices in the book "Beautiful Code: Leading Programmers Explain How They Think" https://www.amazon.com/dp/0596510047

• Read Adam Chapweske's overview of the PS/2 protocol for keyboards and mice.

• Read about the framebuffer in these Baking Pi lessons: Screen 1, Screen 2, Screen 3, Screen 4.

In this first lecture on interrupts, we'll focus on the low-level mechanics and what needs to happen at the assembly level to enable and process an interrupt.

• Handout with selected code from libpi interrupts module.
• Interrupts chapter of Broadcom manual, annotated by Dawson Engler for CS140E

Now we move up to the higher-level abstractions for interrupts, including library support for managing interrupt handlers and best practices for interrupt-safe code.

• Key documentation in Broadcom manual: armtimer, gpio event detection
• Source files for libpi modules: interrupts.c, gpio_interrupts.c, ringbuffer.c, armtimer.c

• Peruse our list of available sensors for possible use in your project.
• Wikipedia entries on analog-to-digital conversion and pulse width modulation.

Anna and Liana will lead a joint session on planning for final project and looking ahead to future adventures.

Representation of signed and unsigned numbers, types and type conversion.

• We'll wind back to the beginning of the quarter and show you how far you've come.
• We'll talk about learning, making, engineering, and what can lie ahead.