kapi: add basic device subsystem

2 files changed, 59 insertions, 0 deletions

diff --git a/kernel/src/devices/root_bus.cpp b/kernel/src/devices/root_bus.cpp
new file mode 100644
index 0000000..a7f3c1a
--- /dev/null
+++ b/kernel/src/devices/root_bus.cpp
@@ -0,0 +1,55 @@
+#include "kernel/devices/root_bus.hpp"
+
+#include "kapi/devices.hpp"
+#include "kapi/devices/bus.hpp"
+#include "kapi/devices/device.hpp"
+#include "kapi/system.hpp"
+
+#include <kstd/memory>
+#include <kstd/print>
+#include <kstd/vector>
+
+#include <algorithm>
+#include <utility>
+
+namespace kernel::devices
+{
+
+  root_bus::root_bus()
+      : kapi::devices::bus{kapi::devices::allocate_major_number(), 0, "system"}
+  {}
+
+  auto root_bus::add_child(kstd::unique_ptr<device> child) -> void
+  {
+    auto observer = m_observers.emplace_back(child.get());
+    m_children.push_back(std::move(child));
+
+    if (m_initialized)
+    {
+      kstd::println("Initializing child device '{}'", observer->name());
+      if (!observer->init())
+      {
+        kapi::system::panic("[kernel:devices] Failed to initialize child device");
+      }
+    }
+  }
+
+  auto root_bus::children() const -> kstd::vector<kstd::observer_ptr<device>> const &
+  {
+    return m_observers;
+  }
+
+  auto root_bus::init() -> bool
+  {
+    if (m_initialized)
+    {
+      kapi::system::panic("[kernel:devices] Root bus already initialized!");
+    }
+
+    return std::ranges::fold_left(m_children, true, [](bool acc, auto & child) -> bool {
+      kstd::println("[kernel:devices] Initializing child device '{}'", child->name());
+      return acc && child->init();
+    });
+  }
+
+}  // namespace kernel::devices
\ No newline at end of file
diff --git a/kernel/src/main.cpp b/kernel/src/main.cpp
index 37b4c5b..9d6028d 100644
--- a/kernel/src/main.cpp
+++ b/kernel/src/main.cpp
@@ -1,6 +1,7 @@
 #include "kapi/boot_modules.hpp"
 #include "kapi/cio.hpp"
 #include "kapi/cpu.hpp"
+#include "kapi/devices.hpp"
 #include "kapi/interrupts.hpp"
 #include "kapi/memory.hpp"
 #include "kapi/system.hpp"
@@ -179,6 +180,9 @@ auto main() -> int
   kstd::println("[OS] Memory subsystem initialized.");
   kapi::system::memory_initialized();
 
+  kapi::devices::init();
+  kstd::println("[OS] System root bus initialized.");
+
   kapi::boot_modules::init();
   kstd::println("[OS] Boot module registry initialized.");