Implement BlDbgPrint() for printing debug messages to the serial console and rename loader entry point

xtldr/CMakeLists.txt

@@ -4,6 +4,7 @@ PROJECT(XTLDR)
 # Specify include directories
 include_directories(
     ${EXECTOS_SOURCE_DIR}/sdk/xtdk
+    ${EXECTOS_SOURCE_DIR}/sdk/xtklib/includes
     ${XTLDR_SOURCE_DIR}/includes)
 
 # Specify list of source code files
@@ -16,6 +17,9 @@ list(APPEND XTLDR_SOURCE
 # Add executable
 add_executable(xtldr ${XTLDR_SOURCE})
 
+# Add linker libraries
+target_link_libraries(xtldr xtklib)
+
 # Set proper binary name and install target
 if(ARCH STREQUAL "i686")
 	set(BINARY_NAME "bootia32")
@@ -26,5 +30,5 @@ set_target_properties(xtldr PROPERTIES OUTPUT_NAME ${BINARY_NAME} SUFFIX .efi)
 set_install_target(xtldr efi/boot)
 
 # Set loader entrypoint, imagebase address, ordinals and subsystem
-set_entrypoint(xtldr "XtLoaderStartup")
+set_entrypoint(xtldr "BlStartXtLoader")
 set_subsystem(xtldr efi_application)

xtldr/efiutil.c

@@ -9,6 +9,35 @@
 #include <xtbl.h>
 
 
+/**
+ * This routine formats the input string and prints it out to the serial console.
+ *
+ * @param Format
+ *        The formatted string that is to be written to the output.
+ *
+ * @param ...
+ *        Depending on the format string, this routine might expect a sequence of additional arguments.
+ *
+ * @return This routine does not return any value.
+ *
+ * @since XT 1.0
+ */
+VOID
+BlDbgPrint(IN PUINT16 Format,
+           IN ...)
+{
+    VA_LIST Arguments;
+
+    /* Initialise the va_list */
+    VA_START(Arguments, Format);
+
+    /* Format and print the string to the serial console */
+    BlStringPrint(BlComPortPutChar, Format, Arguments);
+
+    /* Clean up the va_list */
+    VA_END(Arguments);
+}
+
 /**
  * This routine formats the input string and prints it out to the stdout and serial console.
  *
@@ -22,7 +51,7 @@
  *
  * @since XT 1.0
  *
- * @todo Check if GOP is active and use it instead of default conout protocol; duplicate output to serial console.
+ * @todo Check if GOP is active and use it instead of default conout protocol
  */
 VOID
 BlEfiPrint(IN PUINT16 Format,
@@ -36,6 +65,9 @@ BlEfiPrint(IN PUINT16 Format,
     /* Format and print the string to the stdout */
     BlStringPrint(BlConsolePutChar, Format, Arguments);
 
+    /* Format and print the string to the serial console */
+    BlStringPrint(BlComPortPutChar, Format, Arguments);
+
     /* Clean up the va_list */
     VA_END(Arguments);
 }

xtldr/includes/xtbl.h

@@ -10,6 +10,7 @@
 #define __XTLDR_XTBL_H
 
 #include <xtkmapi.h>
+#include <xtklib.h>
 
 
 /* EFI Image Handle */
@@ -18,6 +19,12 @@ EXTERN EFI_HANDLE EfiImageHandle;
 /* EFI System Table */
 EXTERN EFI_SYSTEM_TABLE *EfiSystemTable;
 
+/* Serial port configuration */
+EXTERN CPPORT EfiSerialPort;
+
+VOID
+BlComPortPutChar(IN USHORT Character);
+
 VOID
 BlConsoleClearScreen();
 
@@ -27,10 +34,18 @@ BlConsoleInitialize();
 VOID
 BlConsolePutChar(IN USHORT Character);
 
+VOID
+BlDbgPrint(IN PUINT16 Format,
+           IN ...);
+
 VOID
 BlEfiPrint(IN PUINT16 Format,
            IN ...);
 
+EFI_STATUS
+BlStartXtLoader(IN EFI_HANDLE ImageHandle,
+                IN PEFI_SYSTEM_TABLE SystemTable);
+
 VOID
 BlStringPrint(IN VOID PutChar(IN USHORT Character),
               IN PUINT16 Format,
@@ -66,8 +81,4 @@ BlpStringPrintUnsigned64(IN VOID PutChar(IN USHORT Character),
 UINT64
 BlpStringReadPadding(IN PUINT16 *Format);
 
-EFI_STATUS
-XtLoaderStartup(IN EFI_HANDLE ImageHandle,
-                IN PEFI_SYSTEM_TABLE SystemTable);
-
 #endif /* __XTLDR_XTBL_H */

xtldr/xtldr.c

@@ -15,6 +15,31 @@ EFI_HANDLE EfiImageHandle;
 /* EFI System Table */
 PEFI_SYSTEM_TABLE EfiSystemTable;
 
+/* Serial port configuration */
+CPPORT EfiSerialPort;
+
+/**
+ * Writes a character to the serial console.
+ *
+ * @param Character
+ *        The integer promotion of the character to be written.
+ *
+ * @return This routine does not return any value.
+ *
+ * @since XT 1.0
+ */
+VOID
+BlComPortPutChar(IN USHORT Character)
+{
+    USHORT Buffer[2];
+
+    /* Write character to the serial console */
+    Buffer[0] = Character;
+    Buffer[1] = 0;
+
+    HlComPortPutByte(&EfiSerialPort, Buffer[0]);
+}
+
 /**
  * This routine is the entry point of the XT EFI boot loader.
  *
@@ -27,10 +52,9 @@ PEFI_SYSTEM_TABLE EfiSystemTable;
  * @return This routine returns status code.
  *
  * @since XT 1.0
- *
  */
 EFI_STATUS
-XtLoaderStartup(IN EFI_HANDLE ImageHandle,
+BlStartXtLoader(IN EFI_HANDLE ImageHandle,
                 IN PEFI_SYSTEM_TABLE SystemTable)
 {
     EFI_STATUS Status;
@@ -39,6 +63,12 @@ XtLoaderStartup(IN EFI_HANDLE ImageHandle,
     EfiImageHandle = ImageHandle;
     EfiSystemTable = SystemTable;
 
+    Status = HlInitializeComPort(&EfiSerialPort, 1, 0);
+    if(Status != STATUS_SUCCESS)
+    {
+        BlEfiPrint(L"Failed to initialize serial console");
+    }
+
     /* Initialize EFI console */
     Status = BlConsoleInitialize();
     if(Status != STATUS_EFI_SUCCESS) {