1 files changed, 78 insertions, 24 deletions

diff --git a/kapi/kapi/system.hpp b/kapi/kapi/system.hpp
index 80233507..d8a306d3 100644
--- a/kapi/kapi/system.hpp
+++ b/kapi/kapi/system.hpp
@@ -6,8 +6,8 @@
 
 #include <array>
 #include <cstddef>
+#include <iterator>
 #include <source_location>
-#include <span>
 #include <string_view>
 #include <type_traits>
 
@@ -17,25 +17,76 @@ namespace kapi::system
   //! @addtogroup kapi-system-kernel-defined
   //! @{
 
-  template<typename... FormatArguments>
-  struct panic_format_string
+  namespace detail
   {
-    kstd::format_string<FormatArguments...> format;
-    std::source_location location;
-
-    template<std::size_t Size>
-    consteval panic_format_string(char const (&format)[Size],  // NOLINT
-                                  std::source_location location = std::source_location::current())
-        : format{format}
-        , location{location}
-    {}
-
-    consteval panic_format_string(std::string_view format,
-                                  std::source_location location = std::source_location::current())
-        : format{format}
-        , location{location}
-    {}
-  };
+    template<typename... FormatArguments>
+    struct panic_format_string
+    {
+      kstd::format_string<FormatArguments...> format;
+      std::source_location location;
+
+      template<std::size_t Size>
+      consteval panic_format_string(char const (&format)[Size],  // NOLINT
+                                    std::source_location location = std::source_location::current())
+          : format{format}
+          , location{location}
+      {}
+
+      consteval panic_format_string(std::string_view format,
+                                    std::source_location location = std::source_location::current())
+          : format{format}
+          , location{location}
+      {}
+    };
+
+    struct panic_buffer
+    {
+      ~panic_buffer();
+
+      void append(char character);
+      void flush();
+
+    private:
+      std::array<char, 16> m_buffer{};
+      std::size_t m_written{};
+    };
+
+    struct panic_iterator
+    {
+      using iterator_category = std::output_iterator_tag;
+      using iterator_concept = std::output_iterator_tag;
+      using difference_type = std::ptrdiff_t;
+      using value_type = void;
+      using pointer = void;
+      using reference = void;
+
+      explicit panic_iterator(panic_buffer & buffer);
+
+      auto operator*() noexcept -> panic_iterator &;
+      auto operator=(char character) -> panic_iterator &;
+      auto operator++() -> panic_iterator &;
+      auto operator++(int) -> panic_iterator;
+
+    private:
+      panic_buffer * m_buffer;
+    };
+
+  }  // namespace detail
+
+  //! Initiate panic processing.
+  //!
+  //! @param location The location where the panic occurred.
+  auto panic_start(std::source_location location) -> void;
+
+  //! Write panic output.
+  //!
+  //! @param message The message to write.
+  auto panic_write(std::string_view message) -> void;
+
+  //! Finish panic processing
+  //!
+  //! @param location The location where the panic occurred.
+  [[noreturn]] auto panic_finish(std::source_location location) -> void;
 
   //! Terminate kernel execution with the given error message.
   //!
@@ -61,14 +112,17 @@ namespace kapi::system
   auto memory_initialized() -> void;
 
   //! @} // end group platform-defined
-  //
+
   template<typename... FormatArguments>
-  [[noreturn]] auto panic(panic_format_string<std::type_identity_t<FormatArguments>...> format,
+  [[noreturn]] auto panic(detail::panic_format_string<std::type_identity_t<FormatArguments>...> format,
                           FormatArguments &&... arguments)
   {
-    auto buffer = std::array<char, 512uz>{};
-    auto [_, length] = kstd::format_to(std::span{buffer}, format.format, std::forward<FormatArguments>(arguments)...);
-    panic(std::string_view{buffer.data(), length}, format.location);
+    panic_start(format.location);
+    {
+      auto buffer = detail::panic_buffer{};
+      kstd::format_to(detail::panic_iterator{buffer}, format.format, std::forward<FormatArguments>(arguments)...);
+    }
+    panic_finish(format.location);
   }
 
 }  // namespace kapi::system