Your starting point

Build firmware intuition, one concept at a time.

Choose a topic that matches your goal. Each path connects three existing, free lessons so you know where to begin and what to explore next.

Embedded C & registers ↓ARM architecture ↓Interrupts & concurrency ↓

Registers and memory

Embedded C in real firmware

Understand what the compiler can assume and how C code interacts with hardware.

Understand volatileWhy use volatile for MMIO? ↗
Apply bit manipulationHow do you set a bit safely? ↗
Think about representationWhy does structure padding matter? ↗

Start this path →

Core architecture

ARM and instruction execution

Connect processor instruction formats with the way code runs and uses memory.

See the architectureExplore RISC and load–store execution ↗
Read machine-level constraintsWhy can't constants fit one instruction? ↗
Understand memory conventionsWhy does the stack grow downward? ↗

Start this path →

Asynchronous events

Interrupts and shared state

Build the reasoning needed to debug races and respond to hardware events.

Compare control flowInterrupts versus polling ↗
Spot a raceInterrupt during read–modify–write ↗
Check your assumptionsWhy isn't volatile thread-safe? ↗

Start this path ↗

Explore freely

Prefer to choose a single topic?

Search the published library or practice Embedded C interview questions in any order.

Browse all resources Open interview practice