Prepare some logging system

kernel/include/logging.hpp

@@ -0,0 +1,26 @@
+//=======================================================================
+// Copyright Baptiste Wicht 2013-2014.
+// Distributed under the Boost Software License, Version 1.0.
+// (See accompanying file LICENSE_1_0.txt or copy at
+//  http://www.boost.org/LICENSE_1_0.txt)
+//=======================================================================
+
+#include <types.hpp>
+#include <string.hpp>
+
+#ifndef LOGGING_HPP
+#define LOGGING_HPP
+
+namespace logging {
+
+bool is_early();
+bool is_file();
+void finalize();
+void to_file();
+
+void log(const char* s);
+void log(const std::string& s);
+
+} //end of namespace logging
+
+#endif

kernel/src/kernel.cpp

@@ -22,6 +22,7 @@
 #include "gdt.hpp"
 #include "terminal.hpp"
 #include "scheduler.hpp"
+#include "logging.hpp"
 #include "vfs/vfs.hpp"
 #include "fs/sysfs.hpp"
 
@@ -62,7 +63,21 @@ void  kernel_main(){
     //Call global constructors
     _init();
 
-    //Finalize memory operations
+    //Try to init VESA
+    if(vesa::vesa_enabled && !vesa::init()){
+        vesa::vesa_enabled = false;
+
+        //Unfortunately, we are in long mode, we cannot go back
+        //to text mode for now
+        suspend_boot();
+    }
+
+    init_console();
+
+    //Starting from here, the logging system can use the console
+    logging::finalize();
+
+    //Finalize memory operations (register sysfs values)
     paging::finalize();
     physical_allocator::finalize();
     virtual_allocator::finalize();
@@ -77,22 +92,14 @@ void  kernel_main(){
     //Init the virtual file system
     vfs::init();
 
-    //Try to init VESA
+    //Starting from here, the logging system can output logs to file
-    if(vesa::vesa_enabled && !vesa::init()){
+    logging::to_file();
-        vesa::vesa_enabled = false;
-
-        //Unfortunately, we are in long mode, we cannot go back
-        //to text mode for now
-        suspend_boot();
-    }
 
     stdio::init_terminals();
 
     //Only install system calls when everything else is ready
     install_system_calls();
 
-    init_console();
-
     sysfs::set_constant_value("/sys/", "version", "0.1");
     sysfs::set_constant_value("/sys/", "author", "Baptiste Wicht");
 

kernel/src/logging.cpp

@@ -0,0 +1,65 @@
+//=======================================================================
+// Copyright Baptiste Wicht 2013-2014.
+// Distributed under the Boost Software License, Version 1.0.
+// (See accompanying file LICENSE_1_0.txt or copy at
+//  http://www.boost.org/LICENSE_1_0.txt)
+//=======================================================================
+
+#include "logging.hpp"
+#include "assert.hpp"
+
+namespace {
+
+bool early = true;
+bool file = false;
+
+constexpr const size_t MAX_EARLY = 128;
+
+size_t current_early = 0;
+const char* early_logs[MAX_EARLY];
+
+} //end of anonymous namespace
+
+bool logging::is_early(){
+    return early;
+}
+
+bool logging::is_file(){
+    return file;
+}
+
+void logging::finalize(){
+    //Starting from there, the messages will be displayed on
+    //the screen
+    early = false;
+}
+
+void logging::to_file(){
+    file = true;
+
+    //TODO
+}
+
+void logging::log(const char* s){
+    if(is_early()){
+        thor_assert(current_early < MAX_EARLY, "early log buffer is full");
+
+        early_logs[current_early++] = s;
+    } else {
+        if(is_file()){
+            //TODO
+        } else {
+            //TODO
+        }
+    }
+}
+
+void logging::log(const std::string& s){
+    thor_assert(!is_early(), "log(string) in only valid in normal mode");
+
+    if(is_file()){
+        //TODO
+    } else {
+        //TODO
+    }
+}