Files
LithosAnanake/include/starkernel/virtio_input.h
T
Robert Allan JamesandClaude Sonnet 5 b031b802e3 Rename FABRIC series: FABRIC.md->0, FABRIC-2.md->1, FABRIC-3.md->2, FABRIC-4.md unchanged
FABRIC.md -> FABRIC-0.md
FABRIC-2.md -> FABRIC-1.md
FABRIC-3.md -> FABRIC-2.md (the current/living document)
FABRIC-4.md unchanged (new #3 to follow separately)

Every cross-reference repo-wide updated to match, including doc-comment
citations inside kernel source (.c/.h) files -- done via an ordered
placeholder substitution (FABRIC-3.md->placeholder2, FABRIC-2.md->
placeholder1, FABRIC.md->placeholder0, then placeholders resolved to
final names) in a single pass per file to avoid double-shifting
already-renamed references.

One line in capsules/font.4th grew past the 64-char block-format limit
as a side effect of the longer filename; shortened it and reverified
with mkcapsule --lint (34/34 pass) before rebuilding.

Verified 3-arch boot to ok> (amd64/aarch64/riscv64, each in the
foreground) after the fix; logs and DoE CSVs from this session's
verification runs included per this repo's own audit-artifact
convention.

Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_019YcT3H2PQeyujrzjqS3Var
2026-09-04 11:22:51 -04:00

68 lines
2.8 KiB
C

/*
* virtio_input.h — Virtio 1.0 input device driver for StarKernel (item 4.3.5c)
*
* riscv64-only today (PCI transport, PLIC interrupt routing). aarch64's
* 4.3.5e reuses this device identity/event shape over the same PCI
* transport with GIC routing instead; riscv64/aarch64-specific pieces stay
* in their own arch trees, not here.
*
* Interrupt-driven end to end: the driver pre-posts empty event buffers
* into the eventq and the device fills+posts them asynchronously, signalled
* by the PLIC (via 4.3.5b's claim/complete substrate) — no polling.
*/
#ifndef STARKERNEL_VIRTIO_INPUT_H
#define STARKERNEL_VIRTIO_INPUT_H
#include <stdint.h>
/* virtio PCI vendor (same device family as virtio-blk) */
#define VIRTIO_INPUT_PCI_VENDOR_ID 0x1AF4u
/* Modern-ID formula 0x1040 + VIRTIO_ID_INPUT, VIRTIO_ID_INPUT = 18, per
* this build host's /usr/include/linux/virtio_ids.h. No legacy/transitional
* ID exists for virtio-input (postdates the legacy 0.9.5 spec). */
#define VIRTIO_INPUT_PCI_DEVICE_ID 0x1052u
/* struct virtio_input_event, per /usr/include/linux/virtio_input.h (BSD
* licensed, same wire format this driver decodes). */
typedef struct {
uint16_t type;
uint16_t code;
uint32_t value;
} VirtioInputEvent;
/* EV_KEY, per /usr/include/linux/input-event-codes.h */
#define VIRTIO_INPUT_EV_KEY 0x01u
/*
* virtio_input_find_keyboard — locate a virtio-keyboard-pci device on the
* PCI bus, initialise the driver, compute and
* enable its PLIC interrupt source (item
* 4.3.5c's own derivation, FABRIC-0.md §27.5.2),
* and pre-post the eventq's receive buffers.
*
* Returns 0 on success.
* Returns -1 if no virtio-keyboard-pci device was found on the PCI bus.
* Returns -2 on driver initialisation failure (bad BAR, queue setup, etc.).
*/
int virtio_input_find_keyboard(void);
/*
* virtio_input_isr — called from riscv64_interrupt_handler() when the PLIC
* claim matches this driver's computed source. Reads the
* ISR-status capability (mandatory — the routed source
* is level-triggered; skipping this leaves it latched),
* drains the used ring, pushes decoded EV_KEY events into
* the diagnostic ring buffer (keyboard_words.c), and
* re-posts drained buffers to the eventq's avail ring.
*/
void virtio_input_isr(void);
/*
* virtio_input_pop_event — diagnostic-ring consumer for keyboard_words.c's
* VKBD-EVENT, same shape as i8042_pop_scancode().
* Returns 1 and fills *code and *value if an event was available, 0 otherwise.
*/
int virtio_input_pop_event(uint16_t *code, uint32_t *value);
#endif /* STARKERNEL_VIRTIO_INPUT_H */