Lab 7 Check

Start with loopback before running two programs. Loopback proves that one UART endpoint can configure itself, send a byte, and receive that byte back through the runtime. After that, run-pair checks whether two independent machines can communicate through a bridged serial link.

machinelab test uart
machinelab run --headless -- build/examples/uart_loopback
machinelab run-pair --headless build/examples/uart_peer_sender --right build/examples/uart_peer_receiver

Discussion Prompts

When reviewing the lab, discuss what fields you would add to a packet protocol built on UART bytes, how a receiver should recover if it starts mid-packet, and why loopback is useful before two-machine communication.

External Reading

For additional background, read OSDev on serial ports and UARTs, plus the Wikibooks guide to 8250/16550 UART programming.