vmm: brokie paging :)

kernel/src/mm/vmm.h

@@ -0,0 +1,45 @@
+/*
+ *  The Soaplin Kernel
+ *  Copyright (C) 2025 The SILD Project
+ *
+ *  vmm.c - Virtual memory manager
+ */
+
+#pragma once
+
+// Page flags
+#include <stdint.h>
+
+#define PTE_ADDR_MASK 0x000ffffffffff000
+#define PTE_GET_ADDR(VALUE) ((VALUE) & PTE_ADDR_MASK)
+#define PTE_GET_FLAGS(VALUE) ((VALUE) & ~PTE_ADDR_MASK)
+
+#define PTE_PRESENT  (1 << 0)
+#define PTE_WRITE    (1 << 1)
+#define PTE_USER     (1 << 2)
+#define PTE_NX       (1ULL << 63) // NX = No eXecute.
+
+typedef uint64_t *pagemap_t;
+
+// These are defined in the linker file.
+extern char reqs_start_ld;
+extern char reqs_end_ld;
+
+extern char text_start_ld;
+extern char text_end_ld;
+
+extern char rodata_start_ld;
+extern char rodata_end_ld;
+
+extern char data_start_ld;
+extern char data_end_ld;
+
+void vmm_init();
+pagemap_t vmm_alloc_pm();
+void vmm_free_pm(pagemap_t pm);
+
+void vmm_map(pagemap_t pm, uint64_t vaddr, uint64_t paddr, uint64_t flags);
+void vmm_map_user(pagemap_t pm, uint64_t vaddr, uint64_t paddr,
+                  uint64_t flags);
+void vmm_unmap(pagemap_t pm, uint64_t vaddr);
+void vmm_protect(pagemap_t pm, uint64_t vaddr, uint64_t flags);