1 files changed, 41 insertions, 0 deletions
diff --git a/kernel/mm/physical_mm/memory_map.c b/kernel/mm/physical_mm/memory_map.c
new file mode 100644
index 0000000..2df905c
--- /dev/null
+++ b/kernel/mm/physical_mm/memory_map.c
@@ -0,0 +1,41 @@
+#include <stdbool.h>
+#include <stdint.h>
+
+#include <mm/memory_map.h>
+#include <mm/physical_mm.h>
+
+/* Marks the block as 'used' */
+ALWAYS_INLINE void
+physical_mm_set_used(const uint32_t bit,
+                     uint32_t *total_free_blocks,
+                     uint32_t *memory_map)
+{
+  uint32_t memory_map_index = bit / BITMAP_ENTRY_SIZE;
+  uint32_t bitmask = 1 << (bit % BITMAP_ENTRY_SIZE);
+  (*total_free_blocks)--;
+  memory_map[memory_map_index] |= bitmask;
+}
+
+/* Marks the block as 'unused' */
+ALWAYS_INLINE void
+physical_mm_set_usable(const uint32_t bit,
+                       uint32_t *total_free_blocks,
+                       uint32_t *memory_map)
+{
+  uint32_t memory_map_index = bit / BITMAP_ENTRY_SIZE;
+  uint32_t bitmask = 1 << (bit % BITMAP_ENTRY_SIZE);
+  (*total_free_blocks)++;
+  memory_map[memory_map_index] &= ~bitmask;
+}
+
+/* Returns:
+ * True if the bit is set (block is in use)
+ * False if the bit is unset (block isn't in use)
+ */
+ALWAYS_INLINE bool
+physical_mm_test_bit(const uint32_t bit, uint32_t *memory_map)
+{
+  uint32_t memory_map_index = bit / BITMAP_ENTRY_SIZE;
+  uint32_t bitmask = 1 << (bit % BITMAP_ENTRY_SIZE);
+  return memory_map[memory_map_index] & bitmask;
+}