Cross-architecture test suite

build.zig

@@ -21,6 +21,13 @@ pub fn build(b: *std.Build) void {
     // jumps/calls that Zig inline asm can't express (see the file's header).
     arch_mod.addAssemblyFile(b.path("src/arch/x86_64/isr.s"));
 
+    // Compile-time config the kernel reads as `@import("build_options")`. The
+    // QEMU test harness sets -Dtest-case=<name> to run one self-test at boot.
+    const test_case = b.option([]const u8, "test-case", "Kernel self-test case to run at boot (see src/tests.zig)");
+    const build_options = b.addOptions();
+    build_options.addOption(?[]const u8, "test_case", test_case);
+    const build_options_mod = build_options.createModule();
+
     // --- Kernel: freestanding x86_64 ELF, jumped to by the bootloader ---
     // SSE2 is part of the x86_64 baseline and UEFI leaves it enabled at handoff,
     // so we keep it: disabling it forces soft-float and makes the compiler unable
@@ -46,6 +53,7 @@ pub fn build(b: *std.Build) void {
             .imports = &.{
                 .{ .name = "danos", .module = mod },
                 .{ .name = "arch", .module = arch_mod },
+                .{ .name = "build_options", .module = build_options_mod },
             },
         }),
     });