first commit

1 files changed, 45 insertions, 0 deletions

diff --git a/kernel/utility.cpp b/kernel/utility.cpp
new file mode 100644
index 0000000..865b817
--- /dev/null
+++ b/kernel/utility.cpp
@@ -0,0 +1,45 @@
+#include <mercury/kernel/utility.hpp>
+
+namespace mercury::kernel::utility {
+
+  void mark_bitmap_region_zero(
+      uint64_t *bitmap, uint64_t start_i, uint64_t end_i) {
+
+    if (start_i % 64 != 0) {
+      uint64_t keep = (1 << (start_i % 64)) - 1;
+      bitmap[start_i / 64] &= keep;
+      start_i = (start_i / 64 + 1) * 64;
+    }
+
+    if (end_i % 64 != 0) {
+      uint64_t replace = (1 << (end_i % 64)) - 1;
+      bitmap[end_i / 64] &= ~replace;
+      end_i = (end_i / 64) * 64;
+    }
+
+    for (uint64_t i = start_i / 64; i < end_i / 64; ++i)
+      bitmap[i] = 0;
+
+  }
+
+  void mark_bitmap_region_one(
+      uint64_t *bitmap, uint64_t start_i, uint64_t end_i) {
+
+    if (start_i % 64 != 0) {
+      uint64_t keep = (1 << (start_i % 64)) - 1;
+      bitmap[start_i / 64] |= ~keep;
+      start_i = (start_i / 64 + 1) * 64;
+    }
+
+    if (end_i % 64 != 0) {
+      uint64_t replace = (1 << (end_i % 64)) - 1;
+      bitmap[end_i / 64] |= replace;
+      end_i = (end_i / 64) * 64;
+    }
+
+    for (uint64_t i = start_i / 64; i < end_i / 64; ++i)
+      bitmap[i] = 0xffffffffffffffff;
+
+  }
+
+}