os: Disable boot output by default, add boot_logger driver, remove silent_start driver, update VGA output

Author: fwsGonzo

api/kernel/os.hpp

@@ -137,12 +137,6 @@ class OS {
    *  Add handler for standard output.
    */
   static void add_stdout(print_func func);
-  /**
-   *  Add stdout handler that simply calls OS::default_stdout
-  **/
-  static void add_default_stdout() {
-    add_stdout(OS::default_stdout);
-  }
 
   /**
    *  The default output method preferred by each platform

src/drivers/CMakeLists.txt

@@ -16,8 +16,8 @@ add_dependencies(vmxnet3 PrecompiledLibraries)
 add_library(heap_debugging STATIC heap_debugging.cpp)
 add_dependencies(heap_debugging PrecompiledLibraries)
 
-add_library(silent_start STATIC silent.cpp)
-add_dependencies(silent_start PrecompiledLibraries)
+add_library(boot_logger STATIC bootlog.cpp)
+add_dependencies(boot_logger PrecompiledLibraries)
 
 add_library(vga_output STATIC vgaout.cpp)
 add_dependencies(vga_output PrecompiledLibraries)
@@ -26,7 +26,7 @@ install(TARGETS
     virtionet virtioblk
     vmxnet3
     heap_debugging
-    silent_start vga_output
+    boot_logger vga_output
     DESTINATION includeos/${ARCH}/drivers)
 
 if(WITH_SOLO5)

src/drivers/silent.cpp src/drivers/bootlog.cppsrc/drivers/silent.cpp renamed to src/drivers/bootlog.cpp

@@ -15,16 +15,5 @@
 // See the License for the specific language governing permissions and
 // limitations under the License.
 
-#include <os>
-#include <kprint>
-
-// prevent default serial out
-void default_stdout_handlers()
-{
-  OS::add_stdout(
-  [] (const char* str, size_t len)
-  {
-    if (OS::is_booted() || OS::is_panicking())
-        OS::default_stdout(str, len);
-  });
-}
+// enable logging during boot
+bool os_enable_boot_logging = true;

src/drivers/vgaout.cpp

@@ -15,10 +15,11 @@
 // See the License for the specific language governing permissions and
 // limitations under the License.
 
-// use VGA as default output instead of serial
 #include <vga>
 
+// output to VGA as well as the default stdout
 void default_stdout_handlers()
 {
+  OS::add_stdout(&OS::default_stdout);
   OS::add_stdout(TextmodeVGA::get().get_print_handler());
 }

src/kernel/os.cpp

@@ -139,12 +139,16 @@ void OS::add_stdout(OS::print_func func)
 __attribute__ ((weak))
 void default_stdout_handlers()
 {
-  OS::add_default_stdout();
+  OS::add_stdout(&OS::default_stdout);
 }
+__attribute__((weak))
+bool os_enable_boot_logging = false;
 void OS::print(const char* str, const size_t len)
 {
-  for (auto& func : os_print_handlers)
-      func(str, len);
+  for (auto& callback : os_print_handlers) {
+    if (os_enable_boot_logging || OS::is_booted() || OS::is_panicking())
+      callback(str, len);
+  }
 }
 
 void OS::legacy_boot() {