audk/OvmfPkg/Library/PlatformDebugLibIoPort/DebugLib.c

/** @file
  Base Debug library instance for QEMU debug port.
  It uses PrintLib to send debug messages to a fixed I/O port.

  Copyright (c) 2006 - 2012, Intel Corporation. All rights reserved.<BR>
  Copyright (c) 2012, Red Hat, Inc.<BR>
  This program and the accompanying materials
  are licensed and made available under the terms and conditions of the BSD License
  which accompanies this distribution.  The full text of the license may be found at
  http://opensource.org/licenses/bsd-license.php.

  THE PROGRAM IS DISTRIBUTED UNDER THE BSD LICENSE ON AN "AS IS" BASIS,
  WITHOUT WARRANTIES OR REPRESENTATIONS OF ANY KIND, EITHER EXPRESS OR IMPLIED.

**/

#include <Base.h>
#include <Uefi.h>
#include <Library/DebugLib.h>
#include <Library/BaseLib.h>
#include <Library/IoLib.h>
#include <Library/PrintLib.h>
#include <Library/PcdLib.h>
#include <Library/BaseMemoryLib.h>
#include <Library/DebugPrintErrorLevelLib.h>

//
// Define the maximum debug and assert message length that this library supports
//
#define MAX_DEBUG_MESSAGE_LENGTH  0x100

/**
  This constructor function does not have to do anything.

  @retval EFI_SUCCESS   The constructor always returns RETURN_SUCCESS.

**/
RETURN_STATUS
EFIAPI
PlatformDebugLibIoPortConstructor (
  VOID
  )
{
  return EFI_SUCCESS;
}

/**
  Prints a debug message to the debug output device if the specified error level is enabled.

  If any bit in ErrorLevel is also set in DebugPrintErrorLevelLib function
  GetDebugPrintErrorLevel (), then print the message specified by Format and the
  associated variable argument list to the debug output device.

  If Format is NULL, then ASSERT().

  @param  ErrorLevel  The error level of the debug message.
  @param  Format      Format string for the debug message to print.
  @param  ...         Variable argument list whose contents are accessed
                      based on the format string specified by Format.

**/
VOID
EFIAPI
DebugPrint (
  IN  UINTN        ErrorLevel,
  IN  CONST CHAR8  *Format,
  ...
  )
{
  CHAR8    Buffer[MAX_DEBUG_MESSAGE_LENGTH];
  VA_LIST  Marker;
  UINT8    *Ptr;

  //
  // If Format is NULL, then ASSERT().
  //
  ASSERT (Format != NULL);

  //
  // Check driver debug mask value and global mask
  //
  if ((ErrorLevel & GetDebugPrintErrorLevel ()) == 0) {
    return;
  }

  //
  // Convert the DEBUG() message to an ASCII String
  //
  VA_START (Marker, Format);
  AsciiVSPrint (Buffer, sizeof (Buffer), Format, Marker);
  VA_END (Marker);

  //
  // Send the print string to the debug I/O port
  //
  for (Ptr = (UINT8 *) Buffer; *Ptr; Ptr++) {
    IoWrite8 (PcdGet16(PcdDebugIoPort), *Ptr);
  }
}


/**
  Prints an assert message containing a filename, line number, and description.
  This may be followed by a breakpoint or a dead loop.

  Print a message of the form "ASSERT <FileName>(<LineNumber>): <Description>\n"
  to the debug output device.  If DEBUG_PROPERTY_ASSERT_BREAKPOINT_ENABLED bit of
  PcdDebugProperyMask is set then CpuBreakpoint() is called. Otherwise, if
  DEBUG_PROPERTY_ASSERT_DEADLOOP_ENABLED bit of PcdDebugProperyMask is set then
  CpuDeadLoop() is called.  If neither of these bits are set, then this function
  returns immediately after the message is printed to the debug output device.
  DebugAssert() must actively prevent recursion.  If DebugAssert() is called while
  processing another DebugAssert(), then DebugAssert() must return immediately.

  If FileName is NULL, then a <FileName> string of "(NULL) Filename" is printed.
  If Description is NULL, then a <Description> string of "(NULL) Description" is printed.

  @param  FileName     The pointer to the name of the source file that generated the assert condition.
  @param  LineNumber   The line number in the source file that generated the assert condition
  @param  Description  The pointer to the description of the assert condition.

**/
VOID
EFIAPI
DebugAssert (
  IN CONST CHAR8  *FileName,
  IN UINTN        LineNumber,
  IN CONST CHAR8  *Description
  )
{
  CHAR8  Buffer[MAX_DEBUG_MESSAGE_LENGTH];
  UINT8 *Ptr;

  //
  // Generate the ASSERT() message in Ascii format
  //
  AsciiSPrint (Buffer, sizeof (Buffer), "ASSERT %a(%d): %a\n", FileName, LineNumber, Description);

  //
  // Send the print string to the Console Output device
  //
  for (Ptr = (UINT8 *) Buffer; *Ptr; Ptr++) {
    IoWrite8 (PcdGet16(PcdDebugIoPort), *Ptr);
  }

  //
  // Generate a Breakpoint, DeadLoop, or NOP based on PCD settings
  //
  if ((PcdGet8(PcdDebugPropertyMask) & DEBUG_PROPERTY_ASSERT_BREAKPOINT_ENABLED) != 0) {
    CpuBreakpoint ();
  } else if ((PcdGet8(PcdDebugPropertyMask) & DEBUG_PROPERTY_ASSERT_DEADLOOP_ENABLED) != 0) {
    CpuDeadLoop ();
  }
}


/**
  Fills a target buffer with PcdDebugClearMemoryValue, and returns the target buffer.

  This function fills Length bytes of Buffer with the value specified by
  PcdDebugClearMemoryValue, and returns Buffer.

  If Buffer is NULL, then ASSERT().
  If Length is greater than (MAX_ADDRESS - Buffer + 1), then ASSERT().

  @param   Buffer  The pointer to the target buffer to be filled with PcdDebugClearMemoryValue.
  @param   Length  The number of bytes in Buffer to fill with zeros PcdDebugClearMemoryValue.

  @return  Buffer  The pointer to the target buffer filled with PcdDebugClearMemoryValue.

**/
VOID *
EFIAPI
DebugClearMemory (
  OUT VOID  *Buffer,
  IN UINTN  Length
  )
{
  //
  // If Buffer is NULL, then ASSERT().
  //
  ASSERT (Buffer != NULL);

  //
  // SetMem() checks for the the ASSERT() condition on Length and returns Buffer
  //
  return SetMem (Buffer, Length, PcdGet8(PcdDebugClearMemoryValue));
}


/**
  Returns TRUE if ASSERT() macros are enabled.

  This function returns TRUE if the DEBUG_PROPERTY_DEBUG_ASSERT_ENABLED bit of
  PcdDebugProperyMask is set.  Otherwise FALSE is returned.

  @retval  TRUE    The DEBUG_PROPERTY_DEBUG_ASSERT_ENABLED bit of PcdDebugProperyMask is set.
  @retval  FALSE   The DEBUG_PROPERTY_DEBUG_ASSERT_ENABLED bit of PcdDebugProperyMask is clear.

**/
BOOLEAN
EFIAPI
DebugAssertEnabled (
  VOID
  )
{
  return (BOOLEAN) ((PcdGet8(PcdDebugPropertyMask) & DEBUG_PROPERTY_DEBUG_ASSERT_ENABLED) != 0);
}


/**
  Returns TRUE if DEBUG() macros are enabled.

  This function returns TRUE if the DEBUG_PROPERTY_DEBUG_PRINT_ENABLED bit of
  PcdDebugProperyMask is set.  Otherwise FALSE is returned.

  @retval  TRUE    The DEBUG_PROPERTY_DEBUG_PRINT_ENABLED bit of PcdDebugProperyMask is set.
  @retval  FALSE   The DEBUG_PROPERTY_DEBUG_PRINT_ENABLED bit of PcdDebugProperyMask is clear.

**/
BOOLEAN
EFIAPI
DebugPrintEnabled (
  VOID
  )
{
  return (BOOLEAN) ((PcdGet8(PcdDebugPropertyMask) & DEBUG_PROPERTY_DEBUG_PRINT_ENABLED) != 0);
}


/**
  Returns TRUE if DEBUG_CODE() macros are enabled.

  This function returns TRUE if the DEBUG_PROPERTY_DEBUG_CODE_ENABLED bit of
  PcdDebugProperyMask is set.  Otherwise FALSE is returned.

  @retval  TRUE    The DEBUG_PROPERTY_DEBUG_CODE_ENABLED bit of PcdDebugProperyMask is set.
  @retval  FALSE   The DEBUG_PROPERTY_DEBUG_CODE_ENABLED bit of PcdDebugProperyMask is clear.

**/
BOOLEAN
EFIAPI
DebugCodeEnabled (
  VOID
  )
{
  return (BOOLEAN) ((PcdGet8(PcdDebugPropertyMask) & DEBUG_PROPERTY_DEBUG_CODE_ENABLED) != 0);
}


/**
  Returns TRUE if DEBUG_CLEAR_MEMORY() macro is enabled.

  This function returns TRUE if the DEBUG_PROPERTY_CLEAR_MEMORY_ENABLED bit of
  PcdDebugProperyMask is set.  Otherwise FALSE is returned.

  @retval  TRUE    The DEBUG_PROPERTY_CLEAR_MEMORY_ENABLED bit of PcdDebugProperyMask is set.
  @retval  FALSE   The DEBUG_PROPERTY_CLEAR_MEMORY_ENABLED bit of PcdDebugProperyMask is clear.

**/
BOOLEAN
EFIAPI
DebugClearMemoryEnabled (
  VOID
  )
{
  return (BOOLEAN) ((PcdGet8(PcdDebugPropertyMask) & DEBUG_PROPERTY_CLEAR_MEMORY_ENABLED) != 0);
}