Daniel Samson
1f2c60b3ec
The kernel publishes the FADT as one more acpi-tables memory resource (tagged by its intact FACP header — the AML blobs are header-stripped); the acpi service reads the PM1 event/control and GPE register ports from that copy, so the kernel's own FADT parse is untouched. A power-protocol module (ServiceId.power = 5, domain-named so an ARM PSCI service can serve the same id) carries subscribe / shutdown / events. The acpi service converts to runtime.service.run — device discovery, the .power protocol, and the SCI notification all fold into one loop. At startup it enables ACPI mode if SCI_EN is clear (the SMI dance), binds the SCI (found as the node's len-1 irq resource, distinct from the broad window), and sets PWRBTN_EN. On the SCI it reads PM1_STS, clears PWRBTN_STS write-1, logs the press, publishes power_button to subscribers, and always acks. The power-button scenario proves it with a real QMP system_powerdown injected mid-run through the M21.0 channel.
69 lines
2.4 KiB
Zig
69 lines
2.4 KiB
Zig
//! The power protocol (docs/m21-plan.md): system power's domain-named surface,
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//! registered under `ServiceId.power`. On x86 the acpi service serves it; on
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//! ARM a PSCI/mailbox service will register the same id — subscribers never
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//! learn which firmware they are on (m19-m20-plan.md decision 7). The
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//! vfs-protocol pattern: extern-struct messages, a version, reserved fields.
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/// The protocol version a client states nowhere yet — reserved for the day a
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/// handshake needs it; requests carry it so a mismatch can be refused loudly.
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pub const version: u16 = 1;
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pub const Operation = enum(u8) {
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/// Subscribe to power events: the subscriber's endpoint rides as the
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/// call's capability (the input/device-manager pattern); events arrive on
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/// it as buffered messages carrying an `EventMessage`.
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subscribe = 1,
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/// Orderly shutdown's last step: enter S5. Accepted only from PID 1
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/// (init) — the process that has already run the stop sequence over
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/// everything else.
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shutdown = 2,
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/// The published event payload (never sent *to* the service).
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event = 3,
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};
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/// What happened. The vocabulary is hardware-neutral: a lid is a lid whether
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/// ACPI or a PSCI mailbox reported it.
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pub const Event = enum(u8) {
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power_button = 1,
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lid = 2,
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ac = 3,
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battery = 4,
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/// A device notification that maps to none of the named events — the
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/// `code` and `hid` fields say which device and what code.
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notify = 5,
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};
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pub const Subscribe = extern struct {
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operation: u8 = @intFromEnum(Operation.subscribe),
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reserved0: u8 = 0,
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version: u16 = version,
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reserved1: u32 = 0,
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};
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pub const Shutdown = extern struct {
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operation: u8 = @intFromEnum(Operation.shutdown),
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reserved0: u8 = 0,
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version: u16 = version,
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reserved1: u32 = 0,
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};
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/// A published event, as the buffered-message payload subscribers receive.
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pub const EventMessage = extern struct {
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operation: u8 = @intFromEnum(Operation.event),
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/// An Event value.
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event: u8,
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reserved0: u16 = 0,
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/// The device notification code (Notify's second argument), or 0.
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code: u32 = 0,
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/// The notifying device's hardware id (EISA-decoded), or all zero.
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hid: [8]u8 = .{0} ** 8,
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};
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pub const Reply = extern struct {
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status: i32,
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reserved: u32 = 0,
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};
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/// Upper bound on any message in this protocol — sizes endpoint buffers.
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pub const message_maximum = 64;
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