feat: add global compile-time configuration header for LumeOS

1 files changed, 34 insertions, 0 deletions

diff --git a/na/include/lume/config.h b/na/include/lume/config.h
new file mode 100644
index 0000000..acd76ef
--- /dev/null
+++ b/na/include/lume/config.h
@@ -0,0 +1,34 @@
+/* SPDX-License-Identifier: GPL-2.0-or-later */
+/* Copyright (C) 2026 Richard Qin */
+
+#pragma once
+
+/*
+ * LumeOS Global Compile-Time Configuration
+ *
+ * All kernel-wide tuning constants live here.
+ * Architecture-specific constants live in <arch/config.h>.
+ *
+ * This header is safe to include from both C++ and assembly files.
+ * Assembly-visible constants use #define; C++ code gets typed constexpr.
+ *
+ * Reference: docs/specs/00_conventions.md §1.3
+ */
+
+/* These macros are shared with assembly (entry.S) */
+#define LUME_MAX_CPUS   8
+#define LUME_PAGE_SIZE  4096
+
+#ifndef __ASSEMBLER__
+
+#include <lume/types.h>
+
+/* Maximum number of CPUs supported by the kernel.
+ * Compile-time limit for static arrays (boot stacks, per-cpu data).
+ * Actual CPU count is detected at runtime via FDT. */
+inline constexpr int kMaxCpus = LUME_MAX_CPUS;
+
+/* Virtual memory page size (4KB, matching SV39 base page). */
+inline constexpr uint64 kPageSize = LUME_PAGE_SIZE;
+
+#endif /* __ASSEMBLER__ */
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