From c2f48fb5df0981df1df23de2b277274f9fe75080 Mon Sep 17 00:00:00 2001
From: Benji Dial <benji@benjidial.net>
Date: Mon, 8 Jan 2024 22:28:41 -0500
Subject: first commit

---
 kernel/utility.cpp | 45 +++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 45 insertions(+)
 create mode 100644 kernel/utility.cpp

(limited to 'kernel/utility.cpp')

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;
+
+  }
+
+}
-- 
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