phil-opp/blog_os

No keyboard input

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#1,173 opened on Nov 14, 2022

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help wanted

Description

I cloned "part12" and built using the standard versions of everything. It works fine except key presses aren't registered. I did a little debugging and the keyboard interrupt is never triggered as far as I can tell. The timer interrupt is triggered normally. I'm using QEMU 7.1.90 on a win10 machine. My host keyboard is a pretty ordinary Norwegian layout USB keyboard. I tried adding "-k no" to the qemu command line, but that made no difference. Any suggestions?

Contributor guide

Tech stack
rust
Domain
backend
Issue type
bug
DifficultyEstimated implementation difficulty for a new contributor, from 1 for very small changes to 5 for expert-level work.
3
Estimated timeA rough time range for an experienced contributor to investigate, implement, test, and prepare a pull request.
half day
Activity statusHow available the issue appears right now: fresh, active, stale, blocked, or waiting on maintainer input.
stale
ClarityHow clearly the issue explains the expected change, acceptance criteria, and next step.
mostly clear
Prerequisites
x86 interrupt handlingRustQEMUdebugging low level code
Newbie friendlinessA 1-100 score estimating how approachable this issue is for first-time contributors.
40
Research direction
The issue reports that keyboard interrupts are never triggered while timer interrupts work. Investigate the keyboard interrupt initialization in the OS kernel, likely in the `interrupts` module. Compare the setup of the keyboard (IRQ 1) with the timer (IRQ 0) in the `init` function. Check if the keyboard interrupt handler is correctly registered and if the APIC or PIC is properly configured. Also verify QEMU's keyboard input is enabled (e.g., no ` nographic` flag). Look at comments or linked PRs for similar issues.