Skip to main content

Loading the code workspace…

LC

Program the 8259 Programmable Interrupt Controller

hard6/15

Implement Interrupt Descriptor Table and Handlers Program the PIT for Kernel Preemption

Language

Compiler

2.0s Limit 256MB

Submit and pass all tests to enable saving to GitHub.

Implementation

Simulate PIC initialization and control in C.

Requirements:

Define PIC_PORTS with command/data for master and slave
Implement pic_send_command() and pic_send_data() that print port operations
Implement pic_remap() with all 4 ICWs for both master and slave
Show correct ICW values being sent
Implement pic_send_eoi() for master, slave, and cascaded interrupts
Implement pic_set_mask() and pic_clear_mask() for individual IRQs
Show IRQ-to-vector mapping after remapping (IRQ0=32, etc.)
Demonstrate masking timer (IRQ0) and unmasking keyboard (IRQ1)
Print initialization sequence step by step

Test:

Show ICW1 sent to both PICs
Show ICW2 with offset 0x20
Show EOI sent for IRQ0 and IRQ1
Show mask being set and cleared

Why This Matters

Remapping the 8259 PIC's IRQ0-15 to vectors 32-47 is a mandatory step in every real x86 kernel, because without it hardware interrupts collide with CPU exception vectors 0-31 and a keyboard press could be misread as a divide-by-zero fault. Forgetting to send EOI after handling an interrupt is why a kernel's very first IRQ0 timer tick often silently hangs all future interrupts.

Hints

0 / 3 revealed

Validation Suite

main.c

Workspace 1.0

← Implement Interrupt Descriptor Table and HandlersProgram the PIT for Kernel Preemption →