add placeholders for display driver

system/drivers/display/display.zig

@@ -0,0 +1,56 @@
+//! /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;
+const device_manager_protocol = runtime.device_manager_protocol;
+var device_id: u64 = 0;
+
+
+fn initialise(endpoint: ipc.Handle) bool {
+    _ = endpoint;
+    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,
+    });
+}