build: factor out kernel API

26 files changed, 162 insertions, 245 deletions

diff --git a/.clang-format b/.clang-format
index b32e8c9..714f716 100644
--- a/.clang-format
+++ b/.clang-format
@@ -40,12 +40,9 @@ DerivePointerAlignment: 'false'
 FixNamespaceComments: 'true'
 IncludeBlocks: Regroup
 IncludeCategories:
-  # Kernel Headers
-  - Regex: 'kern/[[:alnum:]._\/]+\.hpp'
+  # Kernel API Headers
+  - Regex: 'kapi/[[:alnum:]._\/]+\.hpp'
     Priority: 100
-  # Architecture Interface Headers
-  - Regex: 'arch/[[:alnum:]._\/]+\.hpp'
-    Priority: 110
   # Architecture Implementation Headers
   - Regex: 'x86_64/[[:alnum:]._\/]+\.hpp'
     Priority: 110
diff --git a/CMakeLists.txt b/CMakeLists.txt
index aa1f6a9..5dd4044 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -35,15 +35,19 @@ add_compile_options(
 # Kernel Executable
 #]============================================================================]
 
-add_executable("kernel")
-
-add_subdirectory("libs")
-add_subdirectory("kern")
 add_subdirectory("arch")
+add_subdirectory("kapi")
+add_subdirectory("libs")
+
+add_executable("kernel"
+    "src/abort.cpp"
+    "src/kstd.cpp"
+    "src/main.cpp"
+)
 
 target_link_libraries("kernel" PRIVATE
     "arch::${CMAKE_SYSTEM_PROCESSOR}"
-    "os::kern"
+    "api::kapi"
 )
 
 target_link_options("kernel" PRIVATE
diff --git a/arch/CMakeLists.txt b/arch/CMakeLists.txt
index 83da439..516bfe9 100644
--- a/arch/CMakeLists.txt
+++ b/arch/CMakeLists.txt
@@ -1,27 +1,3 @@
-add_library("arch-any" INTERFACE)
-add_library("arch::any" ALIAS "arch-any")
-
-target_sources("arch-any" INTERFACE
-    FILE_SET HEADERS
-    BASE_DIRS "include"
-    FILES
-    "include/arch/io.hpp"
-    "include/arch/memory.hpp"
-    "include/arch/system.hpp"
-)
-
-target_include_directories("arch-any" INTERFACE
-    "include"
-)
-
-target_link_libraries("arch-any" INTERFACE
-    "libs::kstd"
-
-    "c"
-    "gcc"
-    "stdc++"
-)
+set(KERNEL_LINKER_SCRIPT "${CMAKE_CURRENT_SOURCE_DIR}/${CMAKE_SYSTEM_PROCESSOR}/scripts/kernel.ld" PARENT_SCOPE)
 
 add_subdirectory("${CMAKE_SYSTEM_PROCESSOR}")
-
-set(KERNEL_LINKER_SCRIPT "${CMAKE_CURRENT_SOURCE_DIR}/${CMAKE_SYSTEM_PROCESSOR}/scripts/kernel.ld" PARENT_SCOPE)
diff --git a/arch/include/arch/io.hpp b/arch/include/arch/io.hpp
deleted file mode 100644
index 8986b9c..0000000
--- a/arch/include/arch/io.hpp
+++ /dev/null
@@ -1,9 +0,0 @@
-#ifndef TEACHOS_ARCH_IO_HPP
-#define TEACHOS_ARCH_IO_HPP
-
-namespace teachos::arch::io
-{
-  auto init() -> void;
-}
-
-#endif
diff --git a/arch/include/arch/memory.hpp b/arch/include/arch/memory.hpp
deleted file mode 100644
index 33f7fdd..0000000
--- a/arch/include/arch/memory.hpp
+++ /dev/null
@@ -1,9 +0,0 @@
-#ifndef TEACHOS_ARCH_MEMORY_HPP
-#define TEACHOS_ARCH_MEMORY_HPP
-
-namespace teachos::arch::memory
-{
-  auto init() -> void;
-}
-
-#endif
diff --git a/arch/include/arch/system.hpp b/arch/include/arch/system.hpp
deleted file mode 100644
index 73e2463..0000000
--- a/arch/include/arch/system.hpp
+++ /dev/null
@@ -1,9 +0,0 @@
-#ifndef TEACHOS_ARCH_SYSTEM_HPP
-#define TEACHOS_ARCH_SYSTEM_HPP
-
-namespace teachos::arch::system
-{
-  [[noreturn]] auto halt() -> void;
-}
-
-#endif
diff --git a/arch/x86_64/CMakeLists.txt b/arch/x86_64/CMakeLists.txt
index 431520e..4cb20b6 100644
--- a/arch/x86_64/CMakeLists.txt
+++ b/arch/x86_64/CMakeLists.txt
@@ -6,8 +6,7 @@ target_include_directories("arch-x86_64" PUBLIC
 )
 
 target_link_libraries("arch-x86_64" PUBLIC
-    "arch::any"
-    "os::kern"
+    "api::kapi"
     "libs::multiboot2"
 )
 
diff --git a/arch/x86_64/src/io.cpp b/arch/x86_64/src/io.cpp
index 8e9e411..eab6473 100644
--- a/arch/x86_64/src/io.cpp
+++ b/arch/x86_64/src/io.cpp
@@ -1,28 +1,36 @@
-#include "kern/print.hpp"
+#include "kapi/io.hpp"
+
 #include "x86_64/vga/text.hpp"
 
-namespace teachos::arch::io
+namespace teachos::io
 {
 
   auto init() -> void
   {
+    x86_64::vga::text::clear();
     x86_64::vga::text::cursor(false);
+  }
+
+  auto print(std::string_view text) -> void
+  {
+    x86_64::vga::text::write(text, x86_64::vga::text::common_attributes::green_on_black);
+  }
+
+  auto println(std::string_view text) -> void
+  {
+    x86_64::vga::text::write(text, x86_64::vga::text::common_attributes::green_on_black);
+    x86_64::vga::text::newline();
+  }
+
+  auto print_error(std::string_view text) -> void
+  {
+    x86_64::vga::text::write(text, x86_64::vga::text::common_attributes::red_on_black);
+  }
 
-    teachos::set_print_handler(
-        [](auto text) { return x86_64::vga::text::write(text, x86_64::vga::text::common_attributes::green_on_black); });
-    teachos::set_println_handler([](auto text) {
-      x86_64::vga::text::write(text, x86_64::vga::text::common_attributes::green_on_black);
-      x86_64::vga::text::newline();
-    });
-
-    teachos::set_print_error_handler(
-        [](auto text) { return x86_64::vga::text::write(text, x86_64::vga::text::common_attributes::red_on_black); });
-    teachos::set_println_error_handler([](auto text) {
-      x86_64::vga::text::write(text, x86_64::vga::text::common_attributes::red_on_black);
-      x86_64::vga::text::newline();
-    });
-
-    teachos::println("[x86-64] Basic VGA text output initialized.");
+  auto println_error(std::string_view text) -> void
+  {
+    x86_64::vga::text::write(text, x86_64::vga::text::common_attributes::red_on_black);
+    x86_64::vga::text::newline();
   }
 
-}  // namespace teachos::arch::io
+}  // namespace teachos::io
diff --git a/arch/x86_64/src/memory.cpp b/arch/x86_64/src/memory.cpp
index b6901a5..d1c1f03 100644
--- a/arch/x86_64/src/memory.cpp
+++ b/arch/x86_64/src/memory.cpp
@@ -1,6 +1,6 @@
-#include "arch/memory.hpp"
+#include "kapi/memory.hpp"
 
-#include "kern/error.hpp"
+#include "kapi/system.hpp"
 
 #include "x86_64/boot/boot.hpp"
 #include "x86_64/boot/ld.hpp"
@@ -11,7 +11,7 @@
 
 #include <atomic>
 
-namespace teachos::arch::memory
+namespace teachos::memory
 {
   using namespace x86_64::memory;
   using namespace x86_64::boot;
@@ -36,13 +36,13 @@ namespace teachos::arch::memory
   {
     if (is_initialized.test_and_set())
     {
-      teachos::panic("[x86_64] Memory management has already been initialized.");
+      system::panic("[x86_64] Memory management has already been initialized.");
     }
 
     auto memory_map = multiboot_information_pointer->maybe_memory_map();
     if (!memory_map)
     {
-      teachos::panic("[x86_64] No memory map available.");
+      system::panic("[x86_64] No memory map available.");
     }
 
     auto mem_info = create_memory_information();
@@ -63,4 +63,4 @@ namespace teachos::arch::memory
     // video::vga::text::newline();
   }
 
-}  // namespace teachos::arch::memory
+}  // namespace teachos::memory
diff --git a/arch/x86_64/src/system.cpp b/arch/x86_64/src/system.cpp
index 60ebf0e..2d4c3fe 100644
--- a/arch/x86_64/src/system.cpp
+++ b/arch/x86_64/src/system.cpp
@@ -1,6 +1,6 @@
-#include "arch/system.hpp"
+#include "kapi/system.hpp"
 
-namespace teachos::arch::system
+namespace teachos::system
 {
 
   auto halt() -> void
@@ -9,4 +9,4 @@ namespace teachos::arch::system
     __builtin_unreachable();
   }
 
-}  // namespace teachos::arch::system
+}  // namespace teachos::system
diff --git a/kapi/CMakeLists.txt b/kapi/CMakeLists.txt
new file mode 100644
index 0000000..a3cd040
--- /dev/null
+++ b/kapi/CMakeLists.txt
@@ -0,0 +1,27 @@
+add_library("kapi" OBJECT)
+add_library("api::kapi" ALIAS "kapi")
+
+target_sources("kapi" PUBLIC
+    FILE_SET HEADERS
+    BASE_DIRS "include"
+    FILES
+    "include/kapi/io.hpp"
+    "include/kapi/memory.hpp"
+    "include/kapi/system.hpp"
+)
+
+target_sources("kapi" PRIVATE
+    "src/system.cpp"
+)
+
+target_include_directories("kapi" PUBLIC
+    "include"
+)
+
+target_link_libraries("kapi" PUBLIC
+    "libs::kstd"
+
+    "c"
+    "gcc"
+    "stdc++"
+)
diff --git a/kapi/include/kapi/io.hpp b/kapi/include/kapi/io.hpp
new file mode 100644
index 0000000..764738f
--- /dev/null
+++ b/kapi/include/kapi/io.hpp
@@ -0,0 +1,17 @@
+#ifndef TEACHOS_KAPI_IO_HPP
+#define TEACHOS_KAPI_IO_HPP
+
+#include <string_view>
+
+namespace teachos::io
+{
+  auto init() -> 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;
+}  // namespace teachos::io
+
+#endif
diff --git a/kapi/include/kapi/memory.hpp b/kapi/include/kapi/memory.hpp
new file mode 100644
index 0000000..842a2fa
--- /dev/null
+++ b/kapi/include/kapi/memory.hpp
@@ -0,0 +1,9 @@
+#ifndef TEACHOS_KAPI_MEMORY_HPP
+#define TEACHOS_KAPI_MEMORY_HPP
+
+namespace teachos::memory
+{
+  auto init() -> void;
+}
+
+#endif
diff --git a/kapi/include/kapi/system.hpp b/kapi/include/kapi/system.hpp
new file mode 100644
index 0000000..0d4f2c9
--- /dev/null
+++ b/kapi/include/kapi/system.hpp
@@ -0,0 +1,14 @@
+#ifndef TEACHOS_KAPI_SYSTEM_HPP
+#define TEACHOS_KAPI_SYSTEM_HPP
+
+#include <source_location>
+#include <string_view>
+
+namespace teachos::system
+{
+  [[noreturn]] auto halt() -> void;
+
+  [[noreturn]] auto panic(std::string_view message, std::source_location = std::source_location::current()) -> void;
+}  // namespace teachos::system
+
+#endif
diff --git a/kapi/src/system.cpp b/kapi/src/system.cpp
new file mode 100644
index 0000000..c3b1c5e
--- /dev/null
+++ b/kapi/src/system.cpp
@@ -0,0 +1,18 @@
+#include "kapi/system.hpp"
+
+#include "kapi/io.hpp"
+
+namespace teachos::system
+{
+
+  auto panic(std::string_view message, std::source_location location) -> void
+  {
+    io::println_error("!!!Kernel Panic!!! ");
+    io::println_error(message);
+    io::println_error(location.file_name());
+    io::println_error(location.function_name());
+
+    halt();
+  }
+
+}  // namespace teachos::system
diff --git a/kern/CMakeLists.txt b/kern/CMakeLists.txt
deleted file mode 100644
index 677fdc2..0000000
--- a/kern/CMakeLists.txt
+++ /dev/null
@@ -1,18 +0,0 @@
-add_library("kern" OBJECT)
-add_library("os::kern" ALIAS "kern")
-
-target_sources("kern" PRIVATE
-    "src/abort.cpp"
-    "src/error.cpp"
-    "src/kstd.cpp"
-    "src/main.cpp"
-    "src/print.cpp"
-)
-
-target_include_directories("kern" PUBLIC
-    "include"
-)
-
-target_link_libraries("kern" PUBLIC
-    "arch::any"
-)
diff --git a/kern/include/kern/error.hpp b/kern/include/kern/error.hpp
deleted file mode 100644
index e58b9f1..0000000
--- a/kern/include/kern/error.hpp
+++ /dev/null
@@ -1,13 +0,0 @@
-#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
deleted file mode 100644
index fc9b5d6..0000000
--- a/kern/include/kern/print.hpp
+++ /dev/null
@@ -1,26 +0,0 @@
-
-#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
deleted file mode 100644
index 6db0b74..0000000
--- a/kern/src/abort.cpp
+++ /dev/null
@@ -1,3 +0,0 @@
-#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
deleted file mode 100644
index a5229fd..0000000
--- a/kern/src/error.cpp
+++ /dev/null
@@ -1,19 +0,0 @@
-#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/kstd.cpp b/kern/src/kstd.cpp
deleted file mode 100644
index 1b7050b..0000000
--- a/kern/src/kstd.cpp
+++ /dev/null
@@ -1,10 +0,0 @@
-#include "kern/error.hpp"
-
-#include <kstd/bits/os.hpp>
-
-namespace kstd::os
-{
-
-  auto panic(std::string_view message, std::source_location location) -> void { teachos::panic(message, location); }
-
-}  // namespace kstd::os
\ No newline at end of file
diff --git a/kern/src/main.cpp b/kern/src/main.cpp
deleted file mode 100644
index b99fb37..0000000
--- a/kern/src/main.cpp
+++ /dev/null
@@ -1,14 +0,0 @@
-#include "arch/io.hpp"
-#include "arch/memory.hpp"
-#include "kern/error.hpp"
-#include "kern/print.hpp"
-
-auto main() -> int
-{
-  teachos::arch::io::init();
-  teachos::println("[OS] IO subsystem initialized.");
-
-  teachos::arch::memory::init();
-
-  teachos::panic("Architecture specific main returned!");
-}
diff --git a/kern/src/print.cpp b/kern/src/print.cpp
deleted file mode 100644
index 2c8539b..0000000
--- a/kern/src/print.cpp
+++ /dev/null
@@ -1,51 +0,0 @@
-
-#include "kern/print.hpp"
-
-#include <string_view>
-
-namespace teachos
-{
-  namespace
-  {
-    constinit auto noop = [](std::string_view) {};
-
-    constinit auto current_print_handler = static_cast<print_handler *>(noop);
-    constinit auto current_println_handler = static_cast<println_handler *>(noop);
-    constinit auto current_print_error_handler = static_cast<print_handler *>(noop);
-    constinit auto current_println_error_handler = static_cast<println_handler *>(noop);
-  }  // namespace
-
-  auto print(std::string_view text) -> void { current_print_handler(text); }
-  auto println(std::string_view text) -> void { current_println_handler(text); }
-  auto print_error(std::string_view text) -> void { current_print_error_handler(text); }
-  auto println_error(std::string_view text) -> void { 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
diff --git a/src/abort.cpp b/src/abort.cpp
new file mode 100644
index 0000000..6b0070e
--- /dev/null
+++ b/src/abort.cpp
@@ -0,0 +1,3 @@
+#include "kapi/system.hpp"
+
+extern "C" [[noreturn]] auto abort() -> void { teachos::system::panic("Abort called"); }
diff --git a/src/kstd.cpp b/src/kstd.cpp
new file mode 100644
index 0000000..2149c12
--- /dev/null
+++ b/src/kstd.cpp
@@ -0,0 +1,13 @@
+#include "kapi/system.hpp"
+
+#include <kstd/bits/os.hpp>
+
+namespace kstd::os
+{
+
+  auto panic(std::string_view message, std::source_location location) -> void
+  {
+    teachos::system::panic(message, location);
+  }
+
+}  // namespace kstd::os
\ No newline at end of file
diff --git a/src/main.cpp b/src/main.cpp
new file mode 100644
index 0000000..d6199d0
--- /dev/null
+++ b/src/main.cpp
@@ -0,0 +1,13 @@
+#include "kapi/io.hpp"
+#include "kapi/memory.hpp"
+#include "kapi/system.hpp"
+
+auto main() -> int
+{
+  teachos::io::init();
+  teachos::io::println("[OS] IO subsystem initialized.");
+
+  teachos::memory::init();
+
+  teachos::system::panic("Architecture specific main returned!");
+}