x86_64/debug: add support for QEMU debug console

5 files changed, 61 insertions, 3 deletions

diff --git a/.vscode/tasks.json b/.vscode/tasks.json
index f94098e..e07afd2 100644
--- a/.vscode/tasks.json
+++ b/.vscode/tasks.json
@@ -13,6 +13,8 @@
                 "q35",
                 "-display",
                 "curses",
+                "-debugcon",
+                "file:${workspaceFolder}/qemu-debugcon-${command:cmake.buildType}.log",
                 "-no-reboot",
                 "-d",
                 "int,cpu_reset",
@@ -52,6 +54,8 @@
                 "q35",
                 "-display",
                 "curses",
+                "-debugcon",
+                "file:${workspaceFolder}/qemu-debugcon-${command:cmake.buildType}.log",
                 "-cdrom",
                 "${command:cmake.buildDirectory}/bin/${command:cmake.buildType}/kernel.iso",
                 "2>${workspaceFolder}/qemu-stderr-${command:cmake.buildType}.log"
diff --git a/arch/x86_64/CMakeLists.txt b/arch/x86_64/CMakeLists.txt
index 2505bb6..519fb93 100644
--- a/arch/x86_64/CMakeLists.txt
+++ b/arch/x86_64/CMakeLists.txt
@@ -17,6 +17,9 @@ target_sources("x86_64" PRIVATE
     "src/boot/initialize_runtime.cpp"
     "src/boot/multiboot.s"
 
+    # Debug interfaces
+    "src/debug/qemu_output.cpp"
+
     # api::kapi implementation
     "src/kapi/cio.cpp"
     "src/kapi/cpu.cpp"
diff --git a/arch/x86_64/include/x86_64/debug/qemu_output.hpp b/arch/x86_64/include/x86_64/debug/qemu_output.hpp
new file mode 100644
index 0000000..759a66b
--- /dev/null
+++ b/arch/x86_64/include/x86_64/debug/qemu_output.hpp
@@ -0,0 +1,26 @@
+#ifndef TEACHOS_X86_64_DEBUG_QEMU_OUTPUT_HPP
+#define TEACHOS_X86_64_DEBUG_QEMU_OUTPUT_HPP
+
+#include "kapi/cio.hpp"
+
+#include "x86_64/device_io/port_io.hpp"
+
+#include <string_view>
+
+namespace teachos::debug::x86_64
+{
+  struct qemu_output : cio::output_device
+  {
+    using dbg = io::x86_64::port<0xE9, char, io::x86_64::port_write>;
+
+    qemu_output(output_device & lower);
+
+    auto write(cio::output_stream stream, std::string_view text) -> void override;
+
+  private:
+    output_device & m_lower;
+  };
+
+}  // namespace teachos::debug::x86_64
+
+#endif
\ No newline at end of file
diff --git a/arch/x86_64/src/debug/qemu_output.cpp b/arch/x86_64/src/debug/qemu_output.cpp
new file mode 100644
index 0000000..773306f
--- /dev/null
+++ b/arch/x86_64/src/debug/qemu_output.cpp
@@ -0,0 +1,24 @@
+#include "x86_64/debug/qemu_output.hpp"
+
+#include "kapi/cio.hpp"
+
+#include <string_view>
+
+namespace teachos::debug::x86_64
+{
+
+  qemu_output::qemu_output(output_device & lower)
+      : m_lower{lower}
+  {}
+
+  auto qemu_output::write(cio::output_stream stream, std::string_view text) -> void
+  {
+    for (auto c : text)
+    {
+      dbg::write(c);
+    }
+
+    m_lower.write(stream, text);
+  }
+
+}  // namespace teachos::debug::x86_64
diff --git a/arch/x86_64/src/kapi/cio.cpp b/arch/x86_64/src/kapi/cio.cpp
index 617146e..5594fcc 100644
--- a/arch/x86_64/src/kapi/cio.cpp
+++ b/arch/x86_64/src/kapi/cio.cpp
@@ -1,5 +1,6 @@
 #include "kapi/cio.hpp"
 
+#include "x86_64/debug/qemu_output.hpp"
 #include "x86_64/vga/text.hpp"
 
 #include <optional>
@@ -8,12 +9,12 @@ namespace teachos::cio
 {
 
   auto static constinit vga_device = std::optional<vga::x86_64::text::device>{};
+  auto static constinit dbg_device = std::optional<debug::x86_64::qemu_output>{};
 
   auto init() -> void
   {
-    vga_device.emplace();
-    vga_device->cursor(false);
-    set_output_device(*vga_device);
+    vga_device.emplace().cursor(false);
+    set_output_device(dbg_device.emplace(*vga_device));
   }
 
 }  // namespace teachos::cio