kern/amd64+mu: Add initial virtual memory sources

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

3 files changed, 99 insertions, 0 deletions

diff --git a/sys/inc/arch/amd64/vas.h b/sys/inc/arch/amd64/vas.h
new file mode 100644
index 0000000..eeca5f7
--- /dev/null
+++ b/sys/inc/arch/amd64/vas.h
@@ -0,0 +1,39 @@
+/*
+ * Copyright (c) 2023-2025 Ian Marco Moffett and the Osmora Team.
+ * 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 Hyra 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.
+ */
+
+#ifndef _MACHINE_VAS_H_
+#define _MACHINE_VAS_H_ 1
+
+#include <sys/types.h>
+
+struct mmu_vas {
+    uintptr_t cr3;
+};
+
+#endif  /* !_MACHINE_VAS_H_ */
diff --git a/sys/inc/mu/mmu.h b/sys/inc/mu/mmu.h
new file mode 100644
index 0000000..85f4343
--- /dev/null
+++ b/sys/inc/mu/mmu.h
@@ -0,0 +1,54 @@
+/*
+ * Copyright (c) 2023-2025 Ian Marco Moffett and the Osmora Team.
+ * 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 Hyra 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.
+ */
+
+#ifndef _MU_PMAP_H_
+#define _MU_PMAP_H_ 1
+
+#include <sys/types.h>
+#include <sys/cdefs.h>
+#include <md/vas.h>    /* shared */
+
+/*
+ * Read the currently in-use virtual address space
+ * structure
+ */
+__weak int mu_pmap_readvas(struct mmu_vas *vas);
+
+/*
+ * Write a new virtual address structure to be put
+ * into use as the current address space
+ */
+__weak int mu_pmap_writevas(struct mmu_vas *vas);
+
+/*
+ * Initialize the platform memory management unit
+ */
+__weak void mu_pmap_init(void);
+
+#endif  /* !_MU_PMAP_H_ */
diff --git a/sys/inc/vm/vm.h b/sys/inc/vm/vm.h
index e1866cb..4134005 100644
--- a/sys/inc/vm/vm.h
+++ b/sys/inc/vm/vm.h
@@ -40,4 +40,10 @@ extern volatile struct limine_hhdm_request hhdm_req;
 #define PHYS_TO_VIRT(PHYS) PTR_OFFSET(PHYS, hhdm_req.response->offset)
 #define VIRT_TO_PHYS(VIRT) (uintptr_t)PTR_NOFFET(VIRT, hhdm_req.response->offset)
 
+/*
+ * Initialize the virtual memory management
+ * subsystem
+ */
+void vm_init(void);
+
 #endif  /* !_VM_VM_H_ */