danos/system/drivers/display/display.zig

60 lines
2.3 KiB
Zig

//! /system/drivers/display - the generic display engine driver.
//! This driver is a non official driver for GPU vendors like Intel, NVIDIA, AMD. It provides basic
//! display engine features to the display engine protocol used by the display server, compositor
//! and graphical user interface libraries like Zooeee.
//!
//! This driver is acts like BUS driver, in that it detects the GPU, its capabilities and loads
//! sub-drivers for each device detected. Similar The device manager
//! finds display adaptor e.g. over the PCI/ACPI, and passes the buck on to this driver to handle.
//!
//! The display driver provides the low level part of identifying the device and launching the
//! generic device driver for a GPU vendor.
//!
//! It takes over the framebuffer feature that was setup during system boot.
const std = @import("std");
const runtime = @import("runtime");
const mmio = @import("mmio");
const device = runtime.device;
const dma = runtime.dma;
const shared_memory = runtime.shared_memory;
const system = runtime.system;
const ipc = runtime.ipc;
const display_protocol = runtime.display_protocol;
const scanout_protocol = runtime.scanout_protocol;
var device_id: u64 = 0;
fn initialise(endpoint: ipc.Handle) bool {
_ = endpoint;
// Hello the device manager (role: device — we claim one GPU's PCI function
// and serve its display engine; we report no children). Best-effort: without a
// manager the driver still runs standalone; when present, the manager marks us
// up before the hello deadline and restarts us if we die.
_ = runtime.device_manager.hello(.device, device_id);
return true;
}
fn onMessage(message: []const u8, reply: []u8, sender: u32, capability: ?ipc.Handle) usize {
_ = sender;
_ = capability;
_ = reply;
if (message.len < scanout_protocol.request_size) return 0;
return 0;
}
pub fn main(init: runtime.process.Init) void {
const argument = init.arguments.get(1) orelse {
_ = system.write("display: missing device id (argv[1])\n");
return;
};
device_id = std.fmt.parseInt(u64, argument, 10) catch {
std.log.info("malformed device id '{s}'", .{argument});
return;
};
runtime.service.run(256, .{
.service = .scanout,
.init = initialise,
.on_message = onMessage,
});
}