feat: add initial impl of efi-stub and kernel

drivers/firmware/efi/x86.zig

@@ -0,0 +1,17 @@
+const std = @import("std");
+const console = @import("console.zig");
+const uefi = std.os.uefi;
+const SystemTable = uefi.tables.SystemTable;
+
+export fn efi_pe_entry(image_handle: uefi.Handle, system_table: *SystemTable) callconv(.{ .x86_64_win = .{} }) uefi.Status {
+    const mark_ptr: *usize = @ptrFromInt(0x10000);
+    mark_ptr.* = 0xdeadbeef;
+    _ = image_handle;
+    if (system_table.hdr.signature != SystemTable.signature) {
+        return uefi.Status.invalid_parameter;
+    }
+    console.initUefiConsole(system_table);
+    console.info("Booting YukiOS kernel\n", .{});
+    while(true) {}
+    return .success;
+}