root: Provide entry point if not overriden by importer root source file

1 files changed, 12 insertions, 0 deletions

diff --git a/src/root.zig b/src/root.zig
index 42ef2d0..f0cc048 100644
--- a/src/root.zig
+++ b/src/root.zig
@@ -2,6 +2,8 @@
 //
 // SPDX-License-Identifier: AGPL-3.0-or-later
 
+const builtin = @import("builtin");
+const root = @import("root");
 const std = @import("std");
 pub const hwinfo = @import("hwinfo.zig");
 
@@ -14,6 +16,16 @@ const Result = struct {
 
 const SyscallError = error{Kernel};
 
+fn _start() noreturn {
+    if (!@hasDecl(root, "main")) @compileError("no main function");
+    root.main();
+    end();
+}
+
+comptime {
+    if (!builtin.is_test) @export(_start, .{ .name = "_start" });
+}
+
 fn autoCast(value: anytype) usize {
     return switch (@typeInfo(@TypeOf(value))) {
         .Type => @compileError("cannot pass type to system call"),