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Implement Serial Port Output for Kernel Debugging

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Write a PS/2 Keyboard Driver Write to VGA Text Mode Buffer

Language

Compiler

2.0s Limit 256MB

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Implementation

Implement serial port output for kernel debugging in C.

Requirements:

Define UART register addresses for COM1
Implement serial_init() that sets baud rate and line control
Show divisor calculation for 9600 baud
Implement serial_send_byte() that polls LSR before sending
Implement serial_print() that sends a string
Show Line Status Register being checked
Demonstrate sending "Hello, Kernel!" over serial
Implement serial_received() that checks if data is available
Implement serial_read() that reads one byte from serial
Print initialization configuration

Test:

Show serial port initialized with 9600 baud
Show character being sent with LSR polling
Show string "Hello, Kernel!" transmitted
Show receive buffer status check

Why This Matters

The UART 16550 you're programming here is why `qemu -serial stdio` and real hardware debug cables both work identically — serial output is often the only way to debug a kernel before VGA or any other driver is initialized. Forgetting to poll the Line Status Register before sending a byte is a common bug that silently drops characters when the transmit buffer isn't actually empty yet.

Hints

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Validation Suite

main.c

Workspace 1.0

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