[kernel] Run global constructors

Look up the global constructor list that the linker outputs, and run
them all. Required creation of the `kutil::no_construct` template for
objects that are constructed before the global constructors are run.

Also split the `memory_initialize` function into two - one for just
those objects that need to happen before the global ctors, and one
after.

Tags: memory c++

src/libraries/kutil/include/kutil/logger.h

@@ -18,11 +18,18 @@ enum class level : uint8_t {
 class logger
 {
 public:
+	/// Callback type for immediate-mode logging
+	typedef void (*immediate)(area_t, level, const char *);
+
 	/// Default constructor. Creates a logger without a backing store.
-	logger();
+	/// \arg output  Immediate-mode logging output function
+	logger(immediate output = nullptr);
 
 	/// Constructor. Logs are written to the given buffer.
-	logger(uint8_t *buffer, size_t size);
+	/// \arg buffer  Buffer to which logs are written
+	/// \arg size    Size of `buffer`, in bytes
+	/// \arg output  Immediate-mode logging output function
+	logger(uint8_t *buffer, size_t size, immediate output = nullptr);
 
 	/// Register a log area for future use.
 	/// \arg area      The key for the new area
@@ -30,9 +37,6 @@ public:
 	/// \arg verbosity What level of logs to print for this area
 	void register_area(area_t area, const char *name, level verbosity);
 
-	/// Callback type for immediate-mode logging
-	typedef void (*immediate)(area_t, level, const char *);
-
 	/// Register an immediate-mode log callback
 	inline void set_immediate(immediate cb) { m_immediate = cb; }
 

src/libraries/kutil/include/kutil/no_construct.h

@@ -0,0 +1,15 @@
+#pragma once
+/// \file no_construct.h
+/// Tools for creating objects witout running constructors
+
+namespace kutil {
+
+/// Helper template for creating objects witout running constructors
+template <typename T>
+union no_construct
+{
+	T value;
+	no_construct() {}
+};
+
+} // namespace kutil

src/libraries/kutil/logger.cpp

@@ -21,9 +21,9 @@ using kutil::memcpy;
 logger *logger::s_log = nullptr;
 const char *logger::s_level_names[] = {"", "debug", "info", "warn", "error", "fatal"};
 
-logger::logger() :
+logger::logger(logger::immediate output) :
 	m_buffer(nullptr, 0),
-	m_immediate(nullptr),
+	m_immediate(output),
 	m_sequence(0)
 {
 	memset(&m_levels, 0, sizeof(m_levels));
@@ -31,9 +31,9 @@ logger::logger() :
 	s_log = this;
 }
 
-logger::logger(uint8_t *buffer, size_t size) :
+logger::logger(uint8_t *buffer, size_t size, logger::immediate output) :
 	m_buffer(buffer, size),
-	m_immediate(nullptr),
+	m_immediate(output),
 	m_sequence(0)
 {
 	memset(&m_levels, 0, sizeof(m_levels));