misc: init()->initialize()

1 files changed, 60 insertions, 0 deletions

diff --git a/kernel/mm/physical_mm/bitmap.cc b/kernel/mm/physical_mm/bitmap.cc
new file mode 100644
index 0000000..6284173
--- /dev/null
+++ b/kernel/mm/physical_mm/bitmap.cc
@@ -0,0 +1,60 @@
+/*
+ * bubbl
+ * Copyright (C) 2025  Raghuram Subramani <raghus2247@gmail.com>
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ */
+
+#include <mm/physical_mm.h>
+#include <stdbool.h>
+#include <stdint.h>
+
+namespace PhysicalMM
+{
+
+/* Marks the block as 'used' */
+void
+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' */
+void
+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)
+ */
+bool
+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;
+}
+
+}