x86_64: implement very simple VGA text output

12 files changed, 129 insertions, 9 deletions

diff --git a/.vscode/tasks.json b/.vscode/tasks.json
index db94c63..c280971 100644
--- a/.vscode/tasks.json
+++ b/.vscode/tasks.json
@@ -2,7 +2,7 @@
     "version": "2.0.0",
     "tasks": [
         {
-            "label": "Boot in QEMU",
+            "label": "Debug-Boot in QEMU",
             "command": "qemu-system-x86_64",
             "type": "shell",
             "args": [
@@ -18,6 +18,22 @@
             },
             "group": "none",
             "problemMatcher": []
+        },
+        {
+            "label": "Boot in QEMU",
+            "command": "qemu-system-x86_64",
+            "type": "shell",
+            "args": [
+                "-m",
+                "32M",
+                "-cdrom",
+                "${workspaceFolder}/build/Debug/teachos.iso"
+            ],
+            "presentation": {
+                "reveal": "always"
+            },
+            "group": "none",
+            "problemMatcher": []
         }
     ]
 }
\ No newline at end of file
diff --git a/source/.clang-format b/source/.clang-format
index fbcf7e4..89505b6 100644
--- a/source/.clang-format
+++ b/source/.clang-format
@@ -41,7 +41,7 @@ FixNamespaceComments: 'true'
 IncludeBlocks: Regroup
 IncludeCategories:
   # Local Headers
-  - Regex: '"(.*/)+/.+\.hpp"'
+  - Regex: '"(.*/?)+/.+\.hpp"'
     Priority: 100
   # STL Headers
   - Regex: '<[[:alnum:]._]+(?!\.(h|hpp))>'
diff --git a/source/boot/CMakeLists.txt b/source/boot/CMakeLists.txt
index 5591d70..66f1d65 100644
--- a/source/boot/CMakeLists.txt
+++ b/source/boot/CMakeLists.txt
@@ -8,6 +8,10 @@
 add_library("_boot" STATIC)
 add_library("teachos::boot" ALIAS "_boot")
 
+target_include_directories("_boot" PUBLIC
+  "include"
+)
+
 #[============================================================================[
 # Apply the platform dependent settings to the bootstrapping library.
 #]============================================================================]
diff --git a/source/boot/arch/x86_64/CMakeLists.txt b/source/boot/arch/x86_64/CMakeLists.txt
index 0fd6539..14b0610 100644
--- a/source/boot/arch/x86_64/CMakeLists.txt
+++ b/source/boot/arch/x86_64/CMakeLists.txt
@@ -4,3 +4,7 @@ target_sources("_boot" PRIVATE
   "src/crtn.s"
   "src/multiboot.s"
 )
+
+target_include_directories("_boot" PUBLIC
+  "include"
+)
\ No newline at end of file
diff --git a/source/boot/arch/x86_64/include/boot/pointers.hpp b/source/boot/arch/x86_64/include/boot/pointers.hpp
new file mode 100644
index 0000000..f4f504c
--- /dev/null
+++ b/source/boot/arch/x86_64/include/boot/pointers.hpp
@@ -0,0 +1,12 @@
+#ifndef TEACHOS_ARCH_X86_64_BOOT_POINTERS_HPP
+#define TEACHOS_ARCH_X86_64_BOOT_POINTERS_HPP
+
+#include <cstddef>
+
+namespace teachos::boot
+{
+  extern "C" std::byte const multiboot_information_pointer;
+  extern "C" std::byte * vga_buffer_pointer;
+}  // namespace teachos::boot
+
+#endif
\ No newline at end of file
diff --git a/source/boot/arch/x86_64/src/boot.s b/source/boot/arch/x86_64/src/boot.s
index 4781773..45f261e 100644
--- a/source/boot/arch/x86_64/src/boot.s
+++ b/source/boot/arch/x86_64/src/boot.s
@@ -103,6 +103,7 @@ mesage_long_mode_not_supported:
 /**
  * We need a pointer to our current position in the VGA text buffer.
  */
+.global vga_buffer_pointer
 vga_buffer_pointer: .long 0xb8000
 
 /**
@@ -369,6 +370,5 @@ _transition_to_long_mode:
 
     call _init
 
-    mov multiboot_information_pointer, %rdi
     call kernel_main
     hlt
diff --git a/source/boot/include/boot/asm_pointer.hpp b/source/boot/include/boot/asm_pointer.hpp
new file mode 100644
index 0000000..ec7141e
--- /dev/null
+++ b/source/boot/include/boot/asm_pointer.hpp
@@ -0,0 +1,43 @@
+#ifndef TEACHOS_BOOT_ASM_POINTER_HPP
+#define TEACHOS_BOOT_ASM_POINTER_HPP
+
+namespace teachos::boot
+{
+
+  template<typename Type>
+  struct asm_pointer
+  {
+    constexpr asm_pointer(Type & pointer)
+        : m_pointer{&pointer}
+    {
+    }
+
+    auto constexpr operator->() -> Type * { return m_pointer; }
+    auto constexpr operator->() const -> Type const * { return m_pointer; }
+    auto constexpr operator*() -> Type & { return *m_pointer; }
+    auto constexpr operator*() const -> Type const & { return *m_pointer; }
+
+  private:
+    Type * m_pointer;
+  };
+
+  template<typename Type>
+  struct asm_pointer<Type const>
+  {
+    constexpr asm_pointer(Type const & pointer)
+        : m_pointer{&pointer}
+    {
+    }
+
+    auto constexpr operator->() -> Type const * { return m_pointer; }
+    auto constexpr operator->() const -> Type const * { return m_pointer; }
+    auto constexpr operator*() -> Type const & { return *m_pointer; }
+    auto constexpr operator*() const -> Type const & { return *m_pointer; }
+
+  private:
+    Type const * m_pointer;
+  };
+
+}  // namespace teachos::boot
+
+#endif
\ No newline at end of file
diff --git a/source/cmake/Platforms/x86_64.cmake b/source/cmake/Platforms/x86_64.cmake
index 9e727cf..b681937 100644
--- a/source/cmake/Platforms/x86_64.cmake
+++ b/source/cmake/Platforms/x86_64.cmake
@@ -8,7 +8,7 @@ mark_as_advanced(CRT_BEGIN)
 string(REGEX REPLACE "/crtbegin.o" "" CMAKE_SYSROOT "${CRT_BEGIN}")
 mark_as_advanced(CMAKE_SYSROOT)
 
-set(CMAKE_CXX_FLAGS_INIT "-m64 -mno-red-zone -mcmodel=large")
+set(CMAKE_CXX_FLAGS_INIT "-m64 -mno-red-zone -mcmodel=large -fno-exceptions")
 set(CMAKE_EXE_LINKER_FLAGS_INIT "-nostartfiles")
 set(CMAKE_CXX_LINK_EXECUTABLE
   "<CMAKE_CXX_COMPILER> \
diff --git a/source/kernel/arch/x86_64/CMakeLists.txt b/source/kernel/arch/x86_64/CMakeLists.txt
index 99fafe7..ffce50c 100644
--- a/source/kernel/arch/x86_64/CMakeLists.txt
+++ b/source/kernel/arch/x86_64/CMakeLists.txt
@@ -7,6 +7,7 @@ mark_as_advanced(TEACHOS_KERNEL_LINKER_SCRIPT)
 
 target_sources("kernel" PRIVATE
   "src/entry.cpp"
+  "src/vga.cpp"
 )
 
 target_include_directories("kernel" PRIVATE
diff --git a/source/kernel/arch/x86_64/include/kernel/vga.hpp b/source/kernel/arch/x86_64/include/kernel/vga.hpp
new file mode 100644
index 0000000..ee5a808
--- /dev/null
+++ b/source/kernel/arch/x86_64/include/kernel/vga.hpp
@@ -0,0 +1,11 @@
+#ifndef TEACHOS_KERNEL_VGA_HPP
+#define TEACHOS_KERNEL_VGA_HPP
+
+#include <string_view>
+
+namespace teachos::kernel::vga
+{
+    auto write(std::string_view text, std::byte color) -> void;
+}
+
+#endif
\ No newline at end of file
diff --git a/source/kernel/arch/x86_64/src/entry.cpp b/source/kernel/arch/x86_64/src/entry.cpp
index 2d4e7fb..fd9d9d0 100644
--- a/source/kernel/arch/x86_64/src/entry.cpp
+++ b/source/kernel/arch/x86_64/src/entry.cpp
@@ -1,10 +1,9 @@
-namespace teachos
+#include "kernel/vga.hpp"
+
+namespace teachos::kernel
 {
   extern "C" auto kernel_main() -> void
   {
-    while (true)
-    {
-      asm volatile("nop");
-    }
+    vga::write("TeachOS is starting up...", static_cast<std::byte>(0x4f));
   }
 }  // namespace teachos
diff --git a/source/kernel/arch/x86_64/src/vga.cpp b/source/kernel/arch/x86_64/src/vga.cpp
new file mode 100644
index 0000000..d25eaa5
--- /dev/null
+++ b/source/kernel/arch/x86_64/src/vga.cpp
@@ -0,0 +1,30 @@
+#include "kernel/vga.hpp"
+
+#include "boot/asm_pointer.hpp"
+#include "boot/pointers.hpp"
+
+#include <string_view>
+#include <algorithm>
+
+namespace teachos::kernel::vga
+{
+
+  namespace
+  {
+    auto constinit text_buffer_pointer = boot::asm_pointer{boot::vga_buffer_pointer};
+
+    auto write(char character, std::byte color) -> void
+    {
+      auto & p = *text_buffer_pointer;
+      (*p++) = static_cast<std::byte>(character);
+      (*p++) = color;
+    };
+  }  // namespace
+
+  auto write(std::string_view text, std::byte color) -> void {
+    std::ranges::for_each(text, [&](auto character) {
+        write(character, color);
+    });
+  }
+
+}  // namespace teachos::kernel
\ No newline at end of file