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/control_register.cpp | 72 +++++++++++++++++++++++++
 1 file changed, 72 insertions(+)
 create mode 100644 arch/x86_64/src/kernel/cpu/control_register.cpp

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

diff --git a/arch/x86_64/src/kernel/cpu/control_register.cpp b/arch/x86_64/src/kernel/cpu/control_register.cpp
new file mode 100644
index 0000000..3051bae
--- /dev/null
+++ b/arch/x86_64/src/kernel/cpu/control_register.cpp
@@ -0,0 +1,72 @@
+#include "arch/kernel/cpu/control_register.hpp"
+
+#include "arch/exception_handling/panic.hpp"
+
+#include <type_traits>
+
+namespace teachos::arch::memory::cpu
+{
+  auto read_control_register(control_register cr) -> uint64_t
+  {
+    uint64_t current_value;
+    switch (cr)
+    {
+      case control_register::CR0:
+        asm volatile("mov %%cr0, %[output]" : [output] "=r"(current_value));
+        break;
+      case control_register::CR2:
+        asm volatile("mov %%cr2, %[output]" : [output] "=r"(current_value));
+        break;
+      case control_register::CR3:
+        asm volatile("mov %%cr3, %[output]" : [output] "=r"(current_value));
+        break;
+      case control_register::CR4:
+        asm volatile("mov %%cr4, %[output]" : [output] "=r"(current_value));
+        break;
+      default:
+        exception_handling::panic("[Control Register] Attempted to read non-existent or reserved control register");
+        break;
+    }
+    return current_value;
+  }
+
+  auto write_control_register(control_register cr, uint64_t new_value) -> void
+  {
+    switch (cr)
+    {
+      case control_register::CR0:
+        asm volatile("mov %[input], %%cr0"
+                     : /* no output from call */
+                     : [input] "r"(new_value)
+                     : "memory");
+        break;
+      case control_register::CR2:
+        asm volatile("mov %[input], %%cr2"
+                     : /* no output from call */
+                     : [input] "r"(new_value)
+                     : "memory");
+        break;
+      case control_register::CR3:
+        asm volatile("mov %[input], %%cr3"
+                     : /* no output from call */
+                     : [input] "r"(new_value)
+                     : "memory");
+        break;
+      case control_register::CR4:
+        asm volatile("mov %[input], %%cr4"
+                     : /* no output from call */
+                     : [input] "r"(new_value)
+                     : "memory");
+        break;
+      default:
+        exception_handling::panic("[Control Register] Attempted to write non-existent or reserved control register");
+        break;
+    }
+  }
+
+  auto set_cr0_bit(cr0_flags flag) -> void
+  {
+    auto const cr0 = read_control_register(control_register::CR0);
+    write_control_register(control_register::CR0, static_cast<std::underlying_type<cr0_flags>::type>(flag) | cr0);
+  }
+}  // namespace teachos::arch::memory::cpu
-- 
cgit v1.2.3


From 11db9338dac611ea32e202add5ce5055b54ebb58 Mon Sep 17 00:00:00 2001
From: Fabian Imhof <fabian.imhof@ost.ch>
Date: Thu, 13 Mar 2025 15:46:16 +0000
Subject: fixup typing and continue adding gdt

---
 arch/x86_64/src/kernel/cpu/control_register.cpp | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

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

diff --git a/arch/x86_64/src/kernel/cpu/control_register.cpp b/arch/x86_64/src/kernel/cpu/control_register.cpp
index 3051bae..a39a360 100644
--- a/arch/x86_64/src/kernel/cpu/control_register.cpp
+++ b/arch/x86_64/src/kernel/cpu/control_register.cpp
@@ -4,7 +4,7 @@
 
 #include <type_traits>
 
-namespace teachos::arch::memory::cpu
+namespace teachos::arch::kernel::cpu
 {
   auto read_control_register(control_register cr) -> uint64_t
   {
@@ -69,4 +69,4 @@ namespace teachos::arch::memory::cpu
     auto const cr0 = read_control_register(control_register::CR0);
     write_control_register(control_register::CR0, static_cast<std::underlying_type<cr0_flags>::type>(flag) | cr0);
   }
-}  // namespace teachos::arch::memory::cpu
+}  // namespace teachos::arch::kernel::cpu
-- 
cgit v1.2.3


From 5a8c9d2f2e4a3d2810f81c35070c6ef0926cfdd1 Mon Sep 17 00:00:00 2001
From: Fabian Imhof <fabian.imhof@ost.ch>
Date: Sat, 3 May 2025 09:45:45 +0000
Subject: write wrapper function for syscall

---
 arch/x86_64/src/kernel/cpu/control_register.cpp | 6 ------
 1 file changed, 6 deletions(-)

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

diff --git a/arch/x86_64/src/kernel/cpu/control_register.cpp b/arch/x86_64/src/kernel/cpu/control_register.cpp
index a39a360..41b8cd7 100644
--- a/arch/x86_64/src/kernel/cpu/control_register.cpp
+++ b/arch/x86_64/src/kernel/cpu/control_register.cpp
@@ -23,9 +23,6 @@ namespace teachos::arch::kernel::cpu
       case control_register::CR4:
         asm volatile("mov %%cr4, %[output]" : [output] "=r"(current_value));
         break;
-      default:
-        exception_handling::panic("[Control Register] Attempted to read non-existent or reserved control register");
-        break;
     }
     return current_value;
   }
@@ -58,9 +55,6 @@ namespace teachos::arch::kernel::cpu
                      : [input] "r"(new_value)
                      : "memory");
         break;
-      default:
-        exception_handling::panic("[Control Register] Attempted to write non-existent or reserved control register");
-        break;
     }
   }
 
-- 
cgit v1.2.3