15-minute session: read for 3 minutes, trace for 3, experiment for 7, and complete the check for 2. Spend longer whenever you need.
A hardware interrupt transfers control through architecture-specific entry code. A host callback is not a hardware interrupt. A driver validates device state, manages buffers, and observes ordering rules. Begin with a fake device so you can test invalid lengths and timeouts without writing to arbitrary hardware addresses.
Practice and evidence: Design a read(buffer,length) contract with success, invalid argument, and timeout outcomes. Write one test per outcome before choosing an emulator and documented device.
Keep three notes: your prediction, the actual result, and why they match or differ. The completion check grades understanding; the practice task builds skill.