From 2e4cbd473ff3bb7ac7371af39becf830b4fb753b Mon Sep 17 00:00:00 2001
From: Fabian Imhof <fabian.imhof@ost.ch>
Date: Thu, 13 Mar 2025 14:05:45 +0000
Subject: IN_PROGRESS implement gdt initialization

---
 arch/x86_64/src/kernel/cpu/ss.cpp | 33 +++++++++++++++++++++++++++++++++
 1 file changed, 33 insertions(+)
 create mode 100644 arch/x86_64/src/kernel/cpu/ss.cpp

(limited to 'arch/x86_64/src/kernel/cpu/ss.cpp')

diff --git a/arch/x86_64/src/kernel/cpu/ss.cpp b/arch/x86_64/src/kernel/cpu/ss.cpp
new file mode 100644
index 0000000..b7e52e1
--- /dev/null
+++ b/arch/x86_64/src/kernel/cpu/ss.cpp
@@ -0,0 +1,33 @@
+#include "arch/kernel/cpu/ss.hpp"
+
+namespace teachos::arch::memory::cpu
+{
+  segment_selector::segment_selector(uint16_t index, std::bitset<1U> table_indicator,
+                                     std::bitset<2U> requested_privilege_level)
+      : index(index)
+      , table_indicator(table_indicator)
+      , requested_privilege_level(requested_privilege_level)
+  {
+    // Nothing to do
+  }
+
+  auto segment_selector::to_uint16() const -> uint16_t
+  {
+    return static_cast<uint16_t>((index << 3) | (table_indicator.to_ulong() << 2) |
+                                 requested_privilege_level.to_ulong());
+  }
+
+  auto read_ss() -> uint16_t
+  {
+    uint16_t ss;
+    __asm__("mov %%ss, %0" : "=r"(ss));
+    return ss;
+  }
+
+  auto write_ss(segment_selector selector) -> void
+  {
+    uint16_t ss = selector.to_uint16();
+    __asm__("mov %0, %%ss" ::"r"(ss));
+  }
+
+}  // namespace teachos::arch::memory::cpu
\ No newline at end of file
-- 
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