kernel: restructure devices and drivers

15 files changed, 93 insertions, 40 deletions

diff --git a/cspell.json b/cspell.json
index 26d43d10..88a8db65 100644
--- a/cspell.json
+++ b/cspell.json
@@ -11,6 +11,7 @@
         "cppcoreguidelines",
         "crtc",
         "crtp",
+        "dentry",
         "efer",
         "FACS",
         "fcondition",
diff --git a/kapi/kapi/boot_module/bus.hpp b/kapi/kapi/boot_module/bus.hpp
index 4d195111..2dc1e1b7 100644
--- a/kapi/kapi/boot_module/bus.hpp
+++ b/kapi/kapi/boot_module/bus.hpp
@@ -38,9 +38,9 @@ namespace kapi::boot_modules
   {
     boot_module_device(std::size_t index, boot_module const & module);
 
-    auto command_line() const -> std::string_view override;
+    [[nodiscard]] auto command_line() const -> std::string_view override;
 
-    auto module() const -> boot_module const & override;
+    [[nodiscard]] auto module() const -> boot_module const & override;
 
   protected:
     auto query_interface(kapi::devices::interface interface) -> void * override;
diff --git a/kapi/kapi/boot_modules.hpp b/kapi/kapi/boot_modules.hpp
index 678195c0..56fefe4f 100644
--- a/kapi/kapi/boot_modules.hpp
+++ b/kapi/kapi/boot_modules.hpp
@@ -3,6 +3,7 @@
 
 #include <kapi/boot_module/boot_module.hpp>           // IWYU pragma: export
 #include <kapi/boot_module/boot_module_registry.hpp>  // IWYU pragma: export
+#include <kapi/boot_module/bus.hpp>                   // IWYU pragma: export
 
 namespace kapi::boot_modules
 {
diff --git a/kapi/kapi/devices/driver_registry.hpp b/kapi/kapi/devices/driver_registry.hpp
index 26a81678..8a733c90 100644
--- a/kapi/kapi/devices/driver_registry.hpp
+++ b/kapi/kapi/devices/driver_registry.hpp
@@ -41,7 +41,7 @@ namespace kapi::devices
     //! Driver matching will occur in driver registration order. The highest priority driver will win.
     auto try_bind(kstd::shared_ptr<device> const & device) -> void;
 
-    kstd::vector<kstd::shared_ptr<driver>> m_drivers;
+    kstd::vector<kstd::shared_ptr<driver>> m_drivers{};
   };
 
   //! @}
diff --git a/kernel/CMakeLists.txt b/kernel/CMakeLists.txt
index 700cde8f..082cb7be 100644
--- a/kernel/CMakeLists.txt
+++ b/kernel/CMakeLists.txt
@@ -42,9 +42,12 @@ target_sources("kernel_lib" PRIVATE
     "kernel/devices/block_device_utils.cpp"
     "kernel/devices/root_bus.cpp"
 
+    # Driver Subsystem
+    "kernel/drivers/storage/ram_disk.cpp"
+    "kernel/drivers/init.cpp"
+
     # Storage Device Subsystem
     "kernel/devices/storage.cpp"
-    "kernel/devices/storage/ram_disk/driver.cpp"
 
     # Filesystem Subsystem
     "kernel/filesystem/dentry.cpp"
diff --git a/kernel/kapi/devices.cpp b/kernel/kapi/devices.cpp
index 267bfb4d..64e549f3 100644
--- a/kernel/kapi/devices.cpp
+++ b/kernel/kapi/devices.cpp
@@ -1,8 +1,8 @@
 #include <kapi/devices.hpp>
 
 #include <kernel/devices/root_bus.hpp>
+#include <kernel/drivers/init.hpp>
 
-#include <kapi/devices/driver_registry.hpp>
 #include <kapi/system.hpp>
 #include <kapi/test_support/devices.hpp>
 
@@ -31,7 +31,7 @@ namespace kapi::devices
     }
 
     interface_registry::init();
-    driver_registry::init();
+    kernel::drivers::init();
 
     root_bus = kstd::make_shared<kernel::devices::root_bus>();
     register_device(root_bus);
diff --git a/kernel/kernel/devices/storage.cpp b/kernel/kernel/devices/storage.cpp
index cfdf3ec2..1f74b9af 100644
--- a/kernel/kernel/devices/storage.cpp
+++ b/kernel/kernel/devices/storage.cpp
@@ -1,7 +1,5 @@
 #include <kernel/devices/storage.hpp>
 
-#include <kernel/devices/storage/ram_disk/driver.hpp>
-
 #include <kapi/boot_module/bus.hpp>
 #include <kapi/boot_modules.hpp>
 #include <kapi/devices.hpp>
@@ -13,8 +11,6 @@ namespace kernel::devices::storage
 {
   auto init() -> void
   {
-    kapi::devices::driver_registry::get().add(kstd::make_shared<ram_disk::driver>());
-
     auto modules_bus =
         kstd::make_shared<kapi::boot_modules::boot_module_bus>(&kapi::boot_modules::get_boot_module_registry());
     kapi::devices::get_root_bus()->add_child(modules_bus);
diff --git a/kernel/kernel/drivers/init.cpp b/kernel/kernel/drivers/init.cpp
new file mode 100644
index 00000000..766011ef
--- /dev/null
+++ b/kernel/kernel/drivers/init.cpp
@@ -0,0 +1,21 @@
+#include <kernel/drivers/init.hpp>
+
+#include <kernel/drivers/storage/ram_disk.hpp>
+
+#include <kapi/devices/driver_registry.hpp>
+
+#include <kstd/memory.hpp>
+
+namespace kernel::drivers
+{
+
+  auto init() -> void
+  {
+    kapi::devices::driver_registry::init();
+
+    auto & registry = kapi::devices::driver_registry::get();
+
+    registry.add(kstd::make_shared<kernel::drivers::storage::ram_disk>());
+  }
+
+}  // namespace kernel::drivers
\ No newline at end of file
diff --git a/kernel/kernel/drivers/init.hpp b/kernel/kernel/drivers/init.hpp
new file mode 100644
index 00000000..73dfb9bc
--- /dev/null
+++ b/kernel/kernel/drivers/init.hpp
@@ -0,0 +1,11 @@
+#ifndef TEACHOS_KERNEL_DRIVERS_INIT_HPP
+#define TEACHOS_KERNEL_DRIVERS_INIT_HPP
+
+namespace kernel::drivers
+{
+
+  auto init() -> void;
+
+}
+
+#endif
\ No newline at end of file
diff --git a/kernel/kernel/devices/storage/ram_disk/driver.cpp b/kernel/kernel/drivers/storage/ram_disk.cpp
index 4aedf43b..69256a56 100644
--- a/kernel/kernel/devices/storage/ram_disk/driver.cpp
+++ b/kernel/kernel/drivers/storage/ram_disk.cpp
@@ -1,4 +1,4 @@
-#include <kernel/devices/storage/ram_disk/driver.hpp>
+#include <kernel/drivers/storage/ram_disk.hpp>
 
 #include <kernel/devices/block_device_utils.hpp>
 #include <kernel/filesystem/reserved_numbers.hpp>
@@ -24,16 +24,16 @@
 
 using namespace kstd::units_literals;
 
-namespace kernel::devices::storage::ram_disk
+namespace kernel::drivers::storage
 {
 
   namespace
   {
-    constexpr auto ram_disk_block_size = 512_B;
+    constexpr auto default_block_size = 512_B;
 
-    struct block_device final : kapi::devices::block_device
+    struct block_node final : kapi::devices::block_device
     {
-      explicit block_device(kapi::boot_modules::boot_module const & module)
+      explicit block_node(kapi::boot_modules::boot_module const & module)
           : m_module(module)
       {}
 
@@ -44,7 +44,7 @@ namespace kernel::devices::storage::ram_disk
           kapi::system::panic("[RAM DISK] read_block called with null buffer.");
         }
 
-        auto info = block_device_utils::calculate_transfer(*this, block_index);
+        auto info = devices::block_device_utils::calculate_transfer(*this, block_index);
 
         if (info.to_transfer > 0_B)
         {
@@ -67,7 +67,7 @@ namespace kernel::devices::storage::ram_disk
           kapi::system::panic("[RAM DISK] write_block called with null buffer.");
         }
 
-        auto const info = block_device_utils::calculate_transfer(*this, block_index);
+        auto const info = devices::block_device_utils::calculate_transfer(*this, block_index);
 
         if (info.to_transfer > 0_B)
         {
@@ -80,7 +80,7 @@ namespace kernel::devices::storage::ram_disk
 
       [[nodiscard]] auto block_size() const -> kstd::units::bytes override
       {
-        return ram_disk_block_size;
+        return default_block_size;
       }
 
       [[nodiscard]] auto capacity() const -> kstd::units::bytes override
@@ -94,7 +94,7 @@ namespace kernel::devices::storage::ram_disk
 
   }  // namespace
 
-  auto driver::probe(kapi::devices::device & device) -> kstd::result<void>
+  auto ram_disk::probe(kapi::devices::device & device) -> kstd::result<void>
   {
     auto interface = device.as<kapi::boot_modules::boot_module_identification>();
     if (!interface)
@@ -108,7 +108,7 @@ namespace kernel::devices::storage::ram_disk
       return kstd::failure(make_error_code(kstd::errc::invalid_argument));
     }
 
-    auto implementation = kstd::make_shared<struct block_device>(module);
+    auto implementation = kstd::make_shared<struct block_node>(module);
 
     auto next_index = std::ranges::count_if(
         kapi::devices::interface_registry::get().all(kapi::devices::block_device::id), [this](auto const & published) {
@@ -129,23 +129,23 @@ namespace kernel::devices::storage::ram_disk
     return kstd::success();
   }
 
-  auto driver::unbind(kapi::devices::device & device) -> void
+  auto ram_disk::unbind(kapi::devices::device & device) -> void
   {
     kapi::devices::interface_registry::get().unpublish(device, kapi::devices::block_device::id);
     device.set_driver_data(nullptr);
   }
 
-  auto driver::claimed_parameter() const -> std::pair<std::string_view, std::string_view>
+  auto ram_disk::claimed_parameter() const -> std::pair<std::string_view, std::string_view>
   {
     return {"type", "ramdisk"};
   }
 
-  auto driver::claimed_major() const -> std::optional<std::uint8_t>
+  auto ram_disk::claimed_major() const -> std::optional<std::uint8_t>
   {
     return kernel::filesystem::block_major_numbers::ram_disk;
   }
 
-  auto driver::query_interface(kapi::devices::interface interface) -> void *
+  auto ram_disk::query_interface(kapi::devices::interface interface) -> void *
   {
     if (interface == kapi::boot_modules::boot_module_driver_identification::id)
     {
@@ -155,4 +155,4 @@ namespace kernel::devices::storage::ram_disk
     return kapi::devices::driver::query_interface(interface);
   }
 
-}  // namespace kernel::devices::storage::ram_disk
\ No newline at end of file
+}  // namespace kernel::drivers::storage
\ No newline at end of file
diff --git a/kernel/kernel/devices/storage/ram_disk/driver.hpp b/kernel/kernel/drivers/storage/ram_disk.hpp
index e079d832..973a9e45 100644
--- a/kernel/kernel/devices/storage/ram_disk/driver.hpp
+++ b/kernel/kernel/drivers/storage/ram_disk.hpp
@@ -1,22 +1,20 @@
-#ifndef TEACH_OS_KERNEL_DEVICES_STORAGE_RAM_DISK_DRIVER_HPP
-#define TEACH_OS_KERNEL_DEVICES_STORAGE_RAM_DISK_DRIVER_HPP
+#ifndef TEACH_OS_KERNEL_DRIVERS_STORAGE_RAM_DISK_HPP
+#define TEACH_OS_KERNEL_DRIVERS_STORAGE_RAM_DISK_HPP
 
-#include <kapi/boot_module/bus.hpp>
 #include <kapi/boot_modules.hpp>
 #include <kapi/devices.hpp>
 
 #include <kstd/result.hpp>
-#include <kstd/units.hpp>
 
 #include <cstdint>
 #include <optional>
 #include <string_view>
 #include <utility>
 
-namespace kernel::devices::storage::ram_disk
+namespace kernel::drivers::storage
 {
 
-  struct driver final : kapi::devices::driver, kapi::boot_modules::boot_module_driver_identification
+  struct ram_disk final : kapi::devices::driver, kapi::boot_modules::boot_module_driver_identification
   {
     [[nodiscard]] auto probe(kapi::devices::device & device) -> kstd::result<void> override;
 
@@ -30,6 +28,6 @@ namespace kernel::devices::storage::ram_disk
     auto query_interface(kapi::devices::interface interface) -> void * override;
   };
 
-}  // namespace kernel::devices::storage::ram_disk
+}  // namespace kernel::drivers::storage
 
 #endif
\ No newline at end of file
diff --git a/kernel/kernel/filesystem/type_registry.cpp b/kernel/kernel/filesystem/type_registry.cpp
index 6850090a..0b4cb7ea 100644
--- a/kernel/kernel/filesystem/type_registry.cpp
+++ b/kernel/kernel/filesystem/type_registry.cpp
@@ -74,3 +74,11 @@ namespace kernel::filesystem
   }
 
 }  // namespace kernel::filesystem
+
+namespace kernel::tests::filesystem::type_registry
+{
+  auto deinit() -> void
+  {
+    kernel::filesystem::instance.reset();
+  }
+}  // namespace kernel::tests::filesystem::type_registry
\ No newline at end of file
diff --git a/kernel/kernel/main.cpp b/kernel/kernel/main.cpp
index bc1285c6..aa12df1a 100644
--- a/kernel/kernel/main.cpp
+++ b/kernel/kernel/main.cpp
@@ -156,7 +156,7 @@ auto main() -> int
   kstd::println("[OS] Memory subsystem initialized.");
 
   kapi::devices::init();
-  kstd::println("[OS] System root bus initialized.");
+  kstd::println("[OS] Basic device and driver subsystem initialized.");
 
   kapi::devices::init_platform_drivers();
   kstd::println("[OS] Platform drivers initialized.");
diff --git a/kernel/kernel/test_support/filesystem/type_registry.hpp b/kernel/kernel/test_support/filesystem/type_registry.hpp
new file mode 100644
index 00000000..8d5b6029
--- /dev/null
+++ b/kernel/kernel/test_support/filesystem/type_registry.hpp
@@ -0,0 +1,10 @@
+#ifndef TEACHOS_KERNEL_TEST_SUPPORT_FILESYSTEM_TYPE_REGISTRY_HPP
+#define TEACHOS_KERNEL_TEST_SUPPORT_FILESYSTEM_TYPE_REGISTRY_HPP
+
+namespace kernel::tests::filesystem::type_registry
+{
+  //! Deinitialize the FS type registry singleton.
+  auto deinit() -> void;
+}  // namespace kernel::tests::filesystem::type_registry
+
+#endif
\ No newline at end of file
diff --git a/kernel/kernel/test_support/state_reset_listener.cpp b/kernel/kernel/test_support/state_reset_listener.cpp
index 1f2cb769..cc51d43f 100644
--- a/kernel/kernel/test_support/state_reset_listener.cpp
+++ b/kernel/kernel/test_support/state_reset_listener.cpp
@@ -1,10 +1,13 @@
-#include <kernel/devices/storage/ram_disk/driver.hpp>
+#include <kernel/drivers/storage/ram_disk.hpp>
 #include <kernel/filesystem/open_file_table.hpp>
+#include <kernel/filesystem/type_registry.hpp>
+#include <kernel/filesystem/vfs.hpp>
 #include <kernel/test_support/boot_modules.hpp>
 #include <kernel/test_support/cio.hpp>
 #include <kernel/test_support/cpu.hpp>
 #include <kernel/test_support/filesystem/device_number_registry.hpp>
 #include <kernel/test_support/filesystem/open_file_table.hpp>
+#include <kernel/test_support/filesystem/type_registry.hpp>
 #include <kernel/test_support/filesystem/vfs.hpp>
 #include <kernel/test_support/memory.hpp>
 
@@ -28,28 +31,29 @@ struct state_reset_listener : Catch::EventListenerBase
 
   void testCaseStarting(Catch::TestCaseInfo const &) override
   {
-    kernel::filesystem::open_file_table::init();
-
     kapi::cio::init();
     kapi::cpu::init();
     kapi::memory::init();
     kapi::devices::init();
 
-    kapi::devices::driver_registry::get().add(kstd::make_shared<kernel::devices::storage::ram_disk::driver>());
+    kernel::filesystem::open_file_table::init();
+
+    kapi::devices::driver_registry::get().add(kstd::make_shared<kernel::drivers::storage::ram_disk>());
   }
 
   void testCaseEnded(Catch::TestCaseStats const &) override
   {
     kernel::tests::filesystem::device_number_registry::deinit();
-    kernel::tests::filesystem::open_file_table::deinit();
     kernel::tests::filesystem::vfs::deinit();
+    kernel::tests::filesystem::type_registry::deinit();
+    kernel::tests::filesystem::open_file_table::deinit();
+
     kernel::tests::boot_modules::deinit();
 
+    kapi::test_support::devices::deinit();
     kernel::tests::memory::deinit();
     kernel::tests::cpu::deinit();
     kernel::tests::cio::deinit();
-
-    kapi::test_support::devices::deinit();
   }
 };