Finishing PS/2 bus driver

system/drivers/ps2-bus/mouse.zig

@@ -0,0 +1,50 @@
+//! PS/2 Mouse Driver
+//!
+//! Spawned by the ps2-bus driver once the controller is initialized and port 2
+//! has passed its interface test and device reset. The bus driver hands us our
+//! device HID as argv[1]; we use it to locate our own device descriptor.
+
+const std = @import("std");
+const runtime = @import("runtime");
+const ps2 = @import("ps2-library.zig");
+const device = runtime.device;
+
+fn writeLine(comptime fmt: []const u8, arguments: anytype) void {
+    var line: [128]u8 = undefined;
+    _ = runtime.system.write(std.fmt.bufPrint(&line, fmt, arguments) catch return);
+}
+
+pub fn main() void {
+    const hid = runtime.argument(1);
+    if (hid.len == 0) {
+        _ = runtime.system.write("system/drivers/ps2-bus/mouse: no HID argument\n");
+        return;
+    }
+    writeLine("system/drivers/ps2-bus/mouse: starting for hid {s}\n", .{hid});
+
+    const buffer = runtime.allocator().alloc(device.DeviceDescriptor, 64) catch {
+        _ = runtime.system.write("system/drivers/ps2-bus/mouse: out of memory\n");
+        return;
+    };
+    const mouse_device_descriptor = device.findDeviceDescriptorByHid(buffer, hid) orelse {
+        writeLine("system/drivers/ps2-bus/mouse: no device for hid {s}\n", .{hid});
+        return;
+    };
+
+    // The mouse's own node (PNP0F13) carries IRQ12 and is not claimed by the bus,
+    // so this driver takes exclusive ownership of it. Port IO still goes through
+    // the bus, which owns the shared 8042 ports.
+    if (!device.claim(mouse_device_descriptor.id)) {
+        writeLine("system/drivers/ps2-bus/mouse: unable to claim device for hid {s}\n", .{hid});
+        return;
+    }
+    writeLine("system/drivers/ps2-bus/mouse: claimed device for hid {s}\n", .{hid});
+
+    _ = runtime.system.write("system/drivers/ps2-bus/mouse: ok\n");
+    while (true) runtime.system.sleep(1000);
+}
+
+pub const panic = runtime.panic;
+comptime {
+    _ = &runtime.start._start;
+}