starkernel: item 4.3.5 -- amd64 I/O APIC + i8042 keyboard, interrupt-driven
Punch list §25 item 4.3.5 complete. New ioapic.c/i8042.c drivers (MADT-derived I/O APIC base, no hardcoded constants) plus a KBD-SCAN/KBD-DEBUG diagnostic word pair. Three real bugs found and fixed en route, all blocking this item's own acceptance: a fatal LAPIC spurious-vector crash (nothing had driven a real external interrupt through the I/O APIC before), OVMF leaving the keyboard device itself scanning-disabled (0xF4 fix), and isr.S's stub table only having individually-numbered stubs through vector 32 -- everything above that, including our IRQ1 vector 33, silently reported as vector 255 regardless of which IDT slot actually fired. Verified live via QEMU sendkey against KBD-SCAN: correct XT Set-1 make/break codes for two different keys. Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com>
This commit is contained in:
Robert Allan James
co-authored by
Claude Sonnet 5
Claude Sonnet 5
parent
78ff335b97
commit
88eb73cfe8
@@ -53,9 +53,20 @@
|
||||
/* Heartbeat timer vector (user-defined IRQ space starts at 0x20) */
|
||||
#define APIC_TIMER_VECTOR 0x20
|
||||
|
||||
/* Spurious-interrupt vector (APIC_REG_SIVR, set in apic_init()). A normal,
|
||||
* occasional hardware race per Intel SDM Vol.3 §10.9 -- not a fault. Must
|
||||
* be silently ignored with no EOI. Surfaced by item 4.3.5's I/O APIC work:
|
||||
* no real external interrupt had ever been delivered through the I/O APIC
|
||||
* before, so this path was previously dormant. */
|
||||
#define APIC_SPURIOUS_VECTOR 0xFF
|
||||
|
||||
/* Initialize Local APIC (enables APIC, sets spurious vector) */
|
||||
int apic_init(BootInfo *boot_info);
|
||||
|
||||
/* Return this CPU's xAPIC ID (APIC_REG_ID bits 31:24) — used as the
|
||||
* destination field when programming I/O APIC redirection entries. */
|
||||
uint8_t apic_id(void);
|
||||
|
||||
/* Send End-of-Interrupt signal */
|
||||
void apic_eoi(void);
|
||||
|
||||
|
||||
@@ -0,0 +1,81 @@
|
||||
/*
|
||||
StarForth — Steady-State Virtual Machine Runtime
|
||||
|
||||
Copyright (c) 2023–2025 Robert A. James
|
||||
All rights reserved.
|
||||
|
||||
This file is part of the StarForth project.
|
||||
|
||||
Licensed under the StarForth License, Version 1.0 (the "License");
|
||||
you may not use this file except in compliance with the License.
|
||||
|
||||
You may obtain a copy of the License at:
|
||||
https://github.com/star.4th@proton.me/StarForth/LICENSE.txt
|
||||
|
||||
This software is provided "AS IS", WITHOUT WARRANTY OF ANY KIND,
|
||||
express or implied, including but not limited to the warranties of
|
||||
merchantability, fitness for a particular purpose, and noninfringement.
|
||||
|
||||
See the License for the specific language governing permissions and
|
||||
limitations under the License.
|
||||
|
||||
*/
|
||||
|
||||
/**
|
||||
* i8042.h - PS/2 keyboard controller interface (amd64 only)
|
||||
*
|
||||
* Item 4.3.5 (FABRIC.md §27.5). Interrupt-driven only — no polling of the
|
||||
* status port (0x64) anywhere in this path. Groundwork only: this captures
|
||||
* and prints raw scancodes. Scancode-to-keycode translation and a consumer
|
||||
* API belong to the REPL keyboard-input work noted in FABRIC.md, not here.
|
||||
*/
|
||||
|
||||
#ifndef STARKERNEL_I8042_H
|
||||
#define STARKERNEL_I8042_H
|
||||
|
||||
#include <stdint.h>
|
||||
|
||||
/* IDT vector the I/O APIC delivers legacy IRQ1 to. */
|
||||
#define I8042_KEYBOARD_VECTOR 0x21
|
||||
|
||||
/**
|
||||
* Enable IRQ1 delivery in the i8042 controller's command byte. Assumes the
|
||||
* controller was already brought up by firmware (OVMF) — does not run the
|
||||
* 0xAA self-test or the full two-port init sequence, since that is more
|
||||
* than this item's scope requires.
|
||||
*/
|
||||
void i8042_init(void);
|
||||
|
||||
/**
|
||||
* Drain any byte sitting in the output buffer right before unmasking IRQ1.
|
||||
* Edge-triggered lines only assert on a rising edge; if OBF is already set
|
||||
* (from real wall-clock time elapsing between i8042_init() and unmask
|
||||
* while OBF was already high), there is no edge left to fire on, ever.
|
||||
*/
|
||||
void i8042_drain_stale(void);
|
||||
|
||||
/* Count of real keyboard IRQs serviced since boot (diagnostic). */
|
||||
extern volatile uint32_t g_i8042_isr_count;
|
||||
|
||||
/**
|
||||
* Called from the keyboard IRQ dispatch path (interrupts.c) on every
|
||||
* I8042_KEYBOARD_VECTOR interrupt. Trivial by design: reads the scancode
|
||||
* from port 0x60 (must always be read, or the controller never clears
|
||||
* OBF and stops delivering further interrupts) and pushes it onto a small
|
||||
* ring buffer. No printing, no translation, no other work — that all
|
||||
* happens outside interrupt context via i8042_pop_scancode(). Does not
|
||||
* issue apic_eoi() — the caller does.
|
||||
*/
|
||||
void i8042_handle_irq(void);
|
||||
|
||||
/**
|
||||
* Pop one raw scancode off the ring buffer, from non-interrupt context.
|
||||
* Single producer (the ISR), single reader (this function) — same shape
|
||||
* already established safe on one hart elsewhere in this tree (§21.1).
|
||||
*
|
||||
* @param out Written with the popped scancode on success.
|
||||
* @return 1 if a scancode was popped, 0 if the buffer was empty.
|
||||
*/
|
||||
int i8042_pop_scancode(uint8_t *out);
|
||||
|
||||
#endif /* STARKERNEL_I8042_H */
|
||||
@@ -0,0 +1,68 @@
|
||||
/*
|
||||
StarForth — Steady-State Virtual Machine Runtime
|
||||
|
||||
Copyright (c) 2023–2025 Robert A. James
|
||||
All rights reserved.
|
||||
|
||||
This file is part of the StarForth project.
|
||||
|
||||
Licensed under the StarForth License, Version 1.0 (the "License");
|
||||
you may not use this file except in compliance with the License.
|
||||
|
||||
You may obtain a copy of the License at:
|
||||
https://github.com/star.4th@proton.me/StarForth/LICENSE.txt
|
||||
|
||||
This software is provided "AS IS", WITHOUT WARRANTY OF ANY KIND,
|
||||
express or implied, including but not limited to the warranties of
|
||||
merchantability, fitness for a particular purpose, and noninfringement.
|
||||
|
||||
See the License for the specific language governing permissions and
|
||||
limitations under the License.
|
||||
|
||||
*/
|
||||
|
||||
/**
|
||||
* ioapic.h - I/O APIC interface (amd64 only)
|
||||
*
|
||||
* Item 4.3.5 (FABRIC.md §27.5): no I/O APIC driver existed anywhere in this
|
||||
* tree before this item. The Local APIC (apic.h) self-interrupts for the
|
||||
* timer and needs no routing; any *legacy* IRQ (i8042 keyboard's IRQ1
|
||||
* included) requires the I/O APIC to redirect it to a Local APIC vector.
|
||||
*/
|
||||
|
||||
#ifndef STARKERNEL_IOAPIC_H
|
||||
#define STARKERNEL_IOAPIC_H
|
||||
|
||||
#include <stdint.h>
|
||||
|
||||
/**
|
||||
* Locate and map the I/O APIC via the ACPI MADT (parsed from @p acpi_rsdp).
|
||||
* Also captures any Interrupt Source Override entries so legacy ISA IRQs
|
||||
* with a non-default GSI/polarity/trigger mapping route correctly.
|
||||
*
|
||||
* @param acpi_rsdp BootInfo->acpi_table (RSDP), or NULL.
|
||||
* @return 0 on success, -1 if no MADT/I/O APIC entry was found.
|
||||
*/
|
||||
int ioapic_init(void *acpi_rsdp);
|
||||
|
||||
/**
|
||||
* Program a redirection entry for a legacy ISA IRQ, initially masked.
|
||||
* Honors an Interrupt Source Override for @p isa_irq if the MADT had one
|
||||
* (different GSI, polarity, or trigger mode); otherwise uses the ISA
|
||||
* default (GSI == isa_irq, active-high, edge-triggered) per the ACPI
|
||||
* specification's "conforms to bus" default.
|
||||
*
|
||||
* @param isa_irq Legacy IRQ number (0-15).
|
||||
* @param vector IDT vector to deliver (e.g. 0x21).
|
||||
* @param dest_apic_id Destination Local APIC ID (see apic_id()).
|
||||
* @return 0 on success, -1 if ioapic_init() has not succeeded.
|
||||
*/
|
||||
int ioapic_route_legacy_irq(uint8_t isa_irq, uint8_t vector, uint8_t dest_apic_id);
|
||||
|
||||
/**
|
||||
* Clear the mask bit on a previously routed legacy IRQ's redirection entry.
|
||||
* Call only after ioapic_route_legacy_irq() has programmed it.
|
||||
*/
|
||||
void ioapic_unmask_legacy_irq(uint8_t isa_irq);
|
||||
|
||||
#endif /* STARKERNEL_IOAPIC_H */
|
||||
Reference in New Issue
Block a user