1 files changed, 107 insertions, 0 deletions
diff --git a/src/sys/include/vm/mmu.h b/src/sys/include/vm/mmu.h
new file mode 100644
index 0000000..0edd0bc
--- /dev/null
+++ b/src/sys/include/vm/mmu.h
@@ -0,0 +1,107 @@
+/*
+ * 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: Standard CPU MMU interface
+ * Author: Ian Marco Moffett
+ */
+
+#ifndef _MACHINE_MMU_H_
+#define _MACHINE_MMU_H_
+
+#include <sys/cpuvar.h>
+#include <sys/mman.h>
+#include <sys/param.h>
+#include <vm/vm.h>
+
+/*
+ * Standard memory protection flags
+ */
+#define MMU_PROT_NONE   0x0         /* Nothing */
+#define MMU_PROT_READ   PROT_READ   /* Readable */
+#define MMU_PROT_WRITE  PROT_WRITE  /* Writable */
+#define MMU_PROT_EXEC   PROT_EXEC   /* Executable */
+
+/*
+ * This will represent a virtual to
+ * physical address mapping.
+ *
+ * @va: Virtual address
+ * @pa: Physical address
+ */
+struct mmu_map {
+    vaddr_t va;
+    paddr_t pa;
+};
+
+/*
+ * Represents the current virtual address
+ *
+ * @cr3: The value of CR3 for this VAS
+ */
+struct vm_vas {
+    paddr_t cr3;
+};
+
+/*
+ * Global early kernel VAS structure used in the
+ * creation of new virtual address spaces.
+ */
+extern struct vm_vas g_kvas;
+
+/*
+ * Initialize arch-specific MMU state such as
+ * page tables, initial mappings and sanity checks.
+ *
+ * Returns zero on success, otherwise a less than zero
+ * value on failure.
+ */
+int mmu_init(void);
+
+/*
+ * Map a single virtual page into physical address
+ * space.
+ *
+ * @spec: Mapping specifier (virtual/physical address)
+ * @prot: Protection flags for the mapping (see MMU_PROT_*)
+ */
+int mmu_map_single(struct vm_vas *vas, struct mmu_map *spec, int prot);
+
+/*
+ * Get a pointer to the current virtual address
+ * space.
+ *
+ * @vasres_p: Resulting VAS is written here
+ *
+ * Returns zero on success, otherwise a less than zero
+ * value on failure.
+ */
+int mmu_this_vas(struct vm_vas *vasres_p);
+
+#endif  /* !_MACHINE_MMU_H_ */