7 files changed, 164 insertions, 0 deletions
diff --git a/kern/CMakeLists.txt b/kern/CMakeLists.txt
new file mode 100644
index 0000000..b2c7e2f
--- /dev/null
+++ b/kern/CMakeLists.txt
@@ -0,0 +1,16 @@
+add_library("kern" OBJECT
+    "src/abort.cpp"
+    "src/error.cpp"
+    "src/main.cpp"
+    "src/print.cpp"
+)
+
+target_include_directories("kern" PUBLIC
+    "include"
+)
+
+target_link_libraries("kern" PUBLIC
+    "arch::all"
+
+    "gcc"
+)
diff --git a/kern/include/kern/error.hpp b/kern/include/kern/error.hpp
new file mode 100644
index 0000000..e58b9f1
--- /dev/null
+++ b/kern/include/kern/error.hpp
@@ -0,0 +1,13 @@
+#ifndef TEACHOS_KERN_ERROR_HPP
+#define TEACHOS_KERN_ERROR_HPP
+
+#include <source_location>
+#include <string_view>
+
+namespace teachos
+{
+  [[noreturn]]
+  auto panic(std::string_view message, std::source_location = std::source_location::current()) -> void;
+}
+
+#endif
diff --git a/kern/include/kern/print.hpp b/kern/include/kern/print.hpp
new file mode 100644
index 0000000..fc9b5d6
--- /dev/null
+++ b/kern/include/kern/print.hpp
@@ -0,0 +1,26 @@
+
+#ifndef TEACHOS_KERN_PRINT_HPP
+#define TEACHOS_KERN_PRINT_HPP
+
+#include <string_view>
+
+namespace teachos
+{
+
+  using print_handler = auto(std::string_view) -> void;
+  using println_handler = auto(std::string_view) -> void;
+
+  auto print(std::string_view text) -> void;
+  auto println(std::string_view text) -> void;
+
+  auto print_error(std::string_view text) -> void;
+  auto println_error(std::string_view text) -> void;
+
+  auto set_print_handler(print_handler handler) -> print_handler *;
+  auto set_println_handler(println_handler handler) -> print_handler *;
+  auto set_print_error_handler(print_handler handler) -> print_handler *;
+  auto set_println_error_handler(println_handler handler) -> print_handler *;
+
+}  // namespace teachos
+
+#endif
diff --git a/kern/src/abort.cpp b/kern/src/abort.cpp
new file mode 100644
index 0000000..6db0b74
--- /dev/null
+++ b/kern/src/abort.cpp
@@ -0,0 +1,3 @@
+#include "kern/error.hpp"
+
+extern "C" [[noreturn]] auto abort() -> void { teachos::panic("Abort called"); }
diff --git a/kern/src/error.cpp b/kern/src/error.cpp
new file mode 100644
index 0000000..a5229fd
--- /dev/null
+++ b/kern/src/error.cpp
@@ -0,0 +1,19 @@
+#include "kern/error.hpp"
+
+#include "arch/system.hpp"
+#include "kern/print.hpp"
+
+namespace teachos
+{
+
+  auto panic(std::string_view message, std::source_location location) -> void
+  {
+    println_error("!!!Kernel Panic!!! ");
+    println_error(message);
+    println_error(location.file_name());
+    println_error(location.function_name());
+
+    arch::system::halt();
+  }
+
+}  // namespace teachos
diff --git a/kern/src/main.cpp b/kern/src/main.cpp
new file mode 100644
index 0000000..5e1b6ea
--- /dev/null
+++ b/kern/src/main.cpp
@@ -0,0 +1,11 @@
+#include "arch/io.hpp"
+#include "arch/memory.hpp"
+#include "kern/error.hpp"
+
+auto main() -> int
+{
+  teachos::arch::io::init();
+  teachos::arch::memory::init();
+
+  teachos::panic("Architecture specific main returned!");
+}
diff --git a/kern/src/print.cpp b/kern/src/print.cpp
new file mode 100644
index 0000000..64e2c65
--- /dev/null
+++ b/kern/src/print.cpp
@@ -0,0 +1,76 @@
+
+#include "kern/print.hpp"
+
+#include <string_view>
+
+namespace teachos
+{
+  namespace
+  {
+    print_handler * current_print_handler{};
+    println_handler * current_println_handler{};
+    print_handler * current_print_error_handler{};
+    println_handler * current_println_error_handler{};
+  }  // namespace
+
+  auto print(std::string_view text) -> void
+  {
+    if (current_print_handler)
+    {
+      current_print_handler(text);
+    }
+  }
+
+  auto println(std::string_view text) -> void
+  {
+    if (current_println_handler)
+    {
+      current_println_handler(text);
+    }
+  }
+
+  auto print_error(std::string_view text) -> void
+  {
+    if (current_print_error_handler)
+    {
+      current_print_error_handler(text);
+    }
+  }
+
+  auto println_error(std::string_view text) -> void
+  {
+    if (current_println_error_handler)
+    {
+      current_println_error_handler(text);
+    }
+  }
+
+  auto set_print_handler(print_handler handler) -> print_handler *
+  {
+    auto old = current_print_handler;
+    current_print_handler = handler;
+    return old;
+  }
+
+  auto set_println_handler(println_handler handler) -> print_handler *
+  {
+    auto old = current_println_handler;
+    current_println_handler = handler;
+    return old;
+  }
+
+  auto set_print_error_handler(print_handler handler) -> print_handler *
+  {
+    auto old = current_print_error_handler;
+    current_print_error_handler = handler;
+    return old;
+  }
+
+  auto set_println_error_handler(println_handler handler) -> print_handler *
+  {
+    auto old = current_println_error_handler;
+    current_println_error_handler = handler;
+    return old;
+  }
+
+}  // namespace teachos