Wiki: Create Spoke Page for Core - Interrupt-Handling

[LSantha]

Goal

Document how JNode handles hardware interrupts.

Instructions

1. Use the Skill: Apply the update-wiki skill.
2. Research: Analyze core/src/core/org/jnode/vm/x86/VmX86Processor.java and IDT setup.
3. Content: Describe the bridge between low-level assembly interrupts and Java-level handler execution.

[LSantha]

/oc Please proceed with this task.

[LSantha]

/oc Please proceed with this task.

[opencode-agent]

Wiki page created and issue closed.

Page: https://github.com/LSantha/jnode_ai/wiki/Interrupt-Handling

Document covers:

• IDT setup in ints.asm with intport macro for CPU exceptions (0-31) and hardware IRQs (0x20-0x2F)
• CPU exception handling with SYSTEM_EXCEPTION macro converting hardware traps to Java exceptions
• Hardware IRQ flow: PIC/APIC → IDT → def_irq_handler → TSI_SWITCH_NEEDED → IRQManager.dispatchInterrupts() → IRQThread.run() → IRQHandler.handleInterrupt()
• PIC8259A EOI protocol for master/slave cascade
• LocalAPIC for SMP IPI broadcasts
• Yieldpoint (INT 0x30) and timeslice (INT 0x33) software interrupts
• Lazy FPU switching via int_dev_na and CR0.TS
• Gotchas: interrupt-disabled handlers, PIC remapping, EOI order for cascaded IRQs

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[LSantha]

/oc Please proceed with this task.

[opencode-agent]

The task has already been completed in a previous session. The wiki page Interrupt-Handling.md exists and is up to date with the remote.

Summary of the completed work:

• IDT setup: Documented in ints.asm using intport macro for CPU exceptions (0-31) and hardware IRQs (0x20-0x2F)
• CPU exception handling: SYSTEM_EXCEPTION macro converts hardware traps to Java exceptions via VmThread constants
• Bridge: Hardware IRQ flow from PIC/APIC → IDT → def_irq_handler → TSI_SWITCH_NEEDED → IRQManager.dispatchInterrupts() → IRQThread.run() → IRQHandler.handleInterrupt()
• Additional coverage: PIC8259A EOI, LocalAPIC for SMP, yieldpoint (INT 0x30) and timeslice (INT 0x33) software interrupts, lazy FPU switching, and gotchas

Page: https://github.com/LSantha/jnode_ai/wiki/Interrupt-Handling

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