feat: initial locking etc.

kernel/mem/paging.c

@@ -0,0 +1,58 @@
+//
+// Created by rick on 21-02-21.
+//
+
+#include "paging.h"
+#include <types.h>
+#include <stdbool.h>
+#include <attributes.h>
+
+#define TABLE_ADDR_MASK 0xFFFFF000
+#define DIRECTORY_SIZE 1024
+
+const uint32_t x = TABLE_ADDR_MASK;
+typedef struct {
+    union {
+        struct {
+            bool present: 1;
+            bool read_write: 1;
+            bool user_mode: 1;
+            bool write_through: 1;
+            bool cache_disabled: 1;
+            bool accessed: 1;
+            char ignored: 1;
+            bool page_size: 1;
+            bool global: 1; // ignored
+            uint8_t avail: 3;
+        } packed;
+        uint32_t addr;
+    };
+} packed page_directory_entry;
+
+typedef struct {
+    union {
+        struct {
+            bool present: 1;
+            bool read_write: 1;
+            bool user_supervisor: 1;
+            bool write_through: 1;
+            bool cache_disabled: 1;
+            bool accessed: 1;
+            bool dirty: 1;
+            char ignored: 1;
+            bool global: 1;
+            uint8_t available: 3;
+        } packed;
+        uint32_t addr;
+    };
+} packed page_table_entry;
+
+page_directory_entry page_directory[DIRECTORY_SIZE] at_aligned(4096);
+
+void page_pre_init() {
+    for (int i = 0; i < DIRECTORY_SIZE; ++i) {
+        page_directory[i].read_write = true;
+        page_directory[i].user_mode = false;
+        page_directory[i].present = false;
+    }
+}