From b84c4c9d8c90f3d3fd5a60de282278912fad2f04 Mon Sep 17 00:00:00 2001
From: Felix Morgner <felix.morgner@ost.ch>
Date: Thu, 2 Apr 2026 13:59:27 +0200
Subject: x86_64/devices: implement ISA bus stub

---
 arch/x86_64/CMakeLists.txt           |  4 +++
 arch/x86_64/include/arch/bus/isa.hpp | 31 ++++++++++++++++++++
 arch/x86_64/kapi/devices.cpp         | 22 ++++++++++++++
 arch/x86_64/src/bus/isa.cpp          | 56 ++++++++++++++++++++++++++++++++++++
 4 files changed, 113 insertions(+)
 create mode 100644 arch/x86_64/include/arch/bus/isa.hpp
 create mode 100644 arch/x86_64/kapi/devices.cpp
 create mode 100644 arch/x86_64/src/bus/isa.cpp

(limited to 'arch')

diff --git a/arch/x86_64/CMakeLists.txt b/arch/x86_64/CMakeLists.txt
index 4427e4c..21dceef 100644
--- a/arch/x86_64/CMakeLists.txt
+++ b/arch/x86_64/CMakeLists.txt
@@ -15,6 +15,7 @@ target_sources("x86_64" PRIVATE
     "kapi/boot_modules.cpp"
     "kapi/cio.cpp"
     "kapi/cpu.cpp"
+    "kapi/devices.cpp"
     "kapi/interrupts.cpp"
     "kapi/memory.cpp"
     "kapi/system.cpp"
@@ -24,6 +25,9 @@ target_sources("x86_64" PRIVATE
     "src/cpu/interrupts.cpp"
     "src/cpu/interrupt_stubs.S"
 
+    # Bus Initialization
+    "src/bus/isa.cpp"
+
     # Low-level bootstrap
     "src/boot/boot32.S"
     "src/boot/entry64.s"
diff --git a/arch/x86_64/include/arch/bus/isa.hpp b/arch/x86_64/include/arch/bus/isa.hpp
new file mode 100644
index 0000000..41dda93
--- /dev/null
+++ b/arch/x86_64/include/arch/bus/isa.hpp
@@ -0,0 +1,31 @@
+#ifndef TEACHOS_X86_64_BUS_ISA_HPP
+#define TEACHOS_X86_64_BUS_ISA_HPP
+
+#include "kapi/devices/bus.hpp"
+#include "kapi/devices/device.hpp"
+
+#include <kstd/memory>
+#include <kstd/vector>
+
+namespace arch::bus
+{
+
+  struct isa final : public kapi::devices::bus
+  {
+    isa();
+
+    auto add_child(kstd::unique_ptr<device> child) -> void override;
+
+    [[nodiscard]] auto children() const -> kstd::vector<kstd::observer_ptr<device>> const & override;
+
+    auto init() -> bool override;
+
+  private:
+    kstd::vector<kstd::unique_ptr<device>> m_devices{};
+    kstd::vector<kstd::observer_ptr<device>> m_observers{};
+    bool m_initialized{};
+  };
+
+}  // namespace arch::bus
+
+#endif  // TEACHOS_X86_64_BUS_ISA_HPP
diff --git a/arch/x86_64/kapi/devices.cpp b/arch/x86_64/kapi/devices.cpp
new file mode 100644
index 0000000..25185d6
--- /dev/null
+++ b/arch/x86_64/kapi/devices.cpp
@@ -0,0 +1,22 @@
+#include "kapi/devices.hpp"
+
+#include "arch/bus/isa.hpp"
+
+#include <kstd/memory>
+#include <kstd/print>
+
+#include <utility>
+
+namespace kapi::devices
+{
+
+  auto init_platform_devices() -> void
+  {
+    kstd::println("[x86_64:devices] Initializing ISA bus...");
+    auto isa_bus = kstd::make_unique<arch::bus::isa>();
+
+    auto & root_bus = get_root_bus();
+    root_bus.add_child(std::move(isa_bus));
+  }
+
+}  // namespace kapi::devices
\ No newline at end of file
diff --git a/arch/x86_64/src/bus/isa.cpp b/arch/x86_64/src/bus/isa.cpp
new file mode 100644
index 0000000..3fe4f6f
--- /dev/null
+++ b/arch/x86_64/src/bus/isa.cpp
@@ -0,0 +1,56 @@
+#include "arch/bus/isa.hpp"
+
+#include "kapi/devices.hpp"
+#include "kapi/devices/device.hpp"
+#include "kapi/system.hpp"
+
+#include <kstd/memory>
+#include <kstd/print>
+#include <kstd/vector>
+
+#include <algorithm>
+#include <utility>
+
+namespace arch::bus
+{
+
+  isa::isa()
+      : kapi::devices::bus(kapi::devices::allocate_major_number(), 0, "isa")
+  {}
+
+  auto isa::add_child(kstd::unique_ptr<device> child) -> void
+  {
+    auto observer = m_observers.emplace_back(child.get());
+    m_devices.push_back(std::move(child));
+
+    if (m_initialized)
+    {
+      kstd::println("[bus:{}} Initializing child device '{}'", name(), observer->name());
+      if (!observer->init())
+      {
+        kapi::system::panic("[x86_64:devices] Failed to initialize child device");
+      }
+    }
+  }
+
+  auto isa::children() const -> kstd::vector<kstd::observer_ptr<device>> const &
+  {
+    return m_observers;
+  }
+
+  auto isa::init() -> bool
+  {
+    if (m_initialized)
+    {
+      kapi::system::panic("[x86_64:devices] ISA bus already initialized!");
+    }
+
+    m_initialized = std::ranges::fold_left(m_devices, true, [](bool acc, auto & child) -> bool {
+      kstd::println("[x86_64:devices] Initializing child device '{}'", child->name());
+      return acc && child->init();
+    });
+
+    return m_initialized;
+  }
+
+}  // namespace arch::bus
\ No newline at end of file
-- 
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