Files
danos/system/services/block/protocol.zig
Daniel Samson 3fb9d5936a USB driver stack: xHCI transfers, HID keyboard/mouse, mass storage
Flesh out the xHCI host-controller driver into a full transfer engine and build
the three USB class drivers on top, all verified end to end under QEMU.

- xHCI engine (usb-xhci-library.zig): controller reset, command/event rings with
  cycle-bit bookkeeping (gated on a No-Op-command proof), device slots, Address
  Device, control transfers, full chapter-9 enumeration, Configure Endpoint, and
  interrupt/bulk transfers. Each interface is device_registered with its
  (class,subclass,protocol) identity, unique per (port,interface).
- Bus<->class transfer protocol (usb-transfer-protocol.zig + runtime.usb): open /
  control / interrupt-subscribe (async report pump on a poll timer) / bulk-by-
  physical-address, so sector data never crosses the 256-byte IPC limit.
- USB HID keyboard + mouse (usb-hid/): decode boot-protocol reports and publish
  to the input service. A USB usage is already the input protocol's keycode.
- USB mass storage (usb-storage/): Bulk-Only Transport + transparent SCSI,
  serving a block device under the new .block service id (block-protocol).
- device-manager matches USB interfaces to class drivers (usbDriverForIdentity).
- usb-abi / usb-ids made importable modules; add HID and mass-storage class
  requests, packTriple, and a usb_device DeviceClass.
- Fix test/qemu_test.py on macOS: the QMP unix-socket path was built from the
  deep worktree path and exceeded the 104-byte sun_path limit, so QEMU exited
  before booting. It now lives under a short temp path.

Tests: usb-report, usb-hid, usb-storage pass under python3 test/qemu_test.py;
host units (usb-abi, usb-ids, hid-report, bulk-only-transport, scsi) green.
2026-07-13 14:11:00 +01:00

41 lines
1.6 KiB
Zig

//! The block-device wire protocol — what a filesystem (the FAT server) says to a
//! block driver (usb-storage) over its well-known `.block` endpoint. A protocol
//! module like vfs-protocol / usb-transfer-protocol: extern-struct messages, an
//! `Operation` tag, everything in one IPC message.
//!
//! Data path: read and write move whole blocks to or from a **caller-owned DMA
//! buffer**, named by its physical address — the same physical-address handoff
//! usb-storage already uses toward the controller, one layer up. So a 512-byte
//! sector never has to cross the 256-byte IPC boundary; only the small request /
//! reply headers do. (Safe while the IOMMU is unenforced; see docs/driver-model.md.)
pub const Operation = enum(u32) {
/// geometry() -> { block_size, block_count }
geometry = 0,
/// read(lba, count, physical): read `count` blocks from `lba` into the buffer
read = 1,
/// write(lba, count, physical): write `count` blocks at `lba` from the buffer
write = 2,
};
pub const Request = extern struct {
operation: u32,
reserved: u32 = 0,
lba: u64,
count: u32, // number of blocks (read/write)
reserved2: u32 = 0,
physical: u64, // caller's DMA buffer physical address (read/write)
};
pub const Reply = extern struct {
status: i32, // 0 on success, negative on failure
reserved: u32 = 0,
block_size: u32, // geometry: bytes per block (512)
reserved2: u32 = 0,
block_count: u64, // geometry: total blocks; read/write: blocks moved
};
pub const message_maximum: usize = 256;
pub const request_size: usize = @sizeOf(Request);
pub const reply_size: usize = @sizeOf(Reply);