kern: Add '.modules' section to kernel binary

The '.modules' section stores the list of modules to bring up on early
boot.

Signed-off-by: Ian Moffett <ian@osmora.org>

1 files changed, 89 insertions, 0 deletions

diff --git a/src/sys/include/os/module.h b/src/sys/include/os/module.h
new file mode 100644
index 0000000..f0f7dc0
--- /dev/null
+++ b/src/sys/include/os/module.h
@@ -0,0 +1,89 @@
+/*
+ * Copyright (c) 2025 Ian Marco Moffett and L5 engineers
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions are met:
+ *
+ * 1. Redistributions of source code must retain the above copyright notice,
+ *    this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in the
+ *    documentation and/or other materials provided with the distribution.
+ * 3. Neither the name of the project nor the names of its
+ *    contributors may be used to endorse or promote products derived from
+ *    this software without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
+ * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+ * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE
+ * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
+ * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
+ * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
+ * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
+ * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
+ * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
+ * POSSIBILITY OF SUCH DAMAGE.
+ */
+
+/*
+ * Description: Module interface
+ * Author: Ian Marco Moffett
+ */
+
+#ifndef _OS_MODULE_H_
+#define _OS_MODULE_H_ 1
+
+#include <sys/types.h>
+
+/* Early (high priority)modules */
+extern char __modules_init_start[];
+extern char __modules_init_end[];
+
+/*
+ * Module type enumeration
+ *
+ * @MODTYPE_GENERIC: Generic module/driver
+ * @MODTYPE_PCI: PCI driver
+ */
+typedef enum {
+    MODTYPE_GENERIC,
+    MODTYPE_PCI,
+} modtype_t;
+
+struct module {
+    const char *name;
+    modtype_t type;
+    int(*init)(struct module *modp);
+};
+
+/*
+ * Export a module to be started up upon
+ * early boot.
+ */
+#define MODULE_EXPORT(NAME, TYPE, INIT_FN) \
+    __attribute__((used, section(".modules")))       \
+    struct module __module_##INIT_FN  = {          \
+        .name = (NAME),                             \
+        .type = (TYPE),                             \
+        .init = (INIT_FN)                           \
+    };
+
+/*
+ * XXX: Guarding this in case ever exported
+ */
+#if defined(_KERNEL)
+/*
+ * Used internally to initializemodules
+ */
+#define __MODULES_INIT(TYPE) \
+    for (struct module *__m = (struct module *)__modules_init_start;    \
+         (uintptr_t)__m < (uintptr_t)__modules_init_end; ++__m)         \
+    {                                                                   \
+        if (__m->type == ((TYPE)))                                      \
+            __m->init(__m);                                             \
+    }
+
+#endif  /* _KERNEL */
+#endif  /* !_OS_MODULE_H_ */