x86_64: implement very simple VGA text output

1 files changed, 30 insertions, 0 deletions

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
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