system76-edk2/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 - 2015, 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 <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>
#include "DebugLibDetect.h"

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

/**
  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;
  UINTN    Length;

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

  //
  // Check if the global mask disables this message or the device is inactive
  //
  if ((ErrorLevel & GetDebugPrintErrorLevel ()) == 0 ||
      !PlatformDebugLibIoPortFound ()) {
    return;
  }

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

  //
  // Send the print string to the debug I/O port
  //
  IoWriteFifo8 (PcdGet16 (PcdDebugIoPort), Length, Buffer);
}


/**
  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];
  UINTN  Length;

  //
  // Generate the ASSERT() message in Ascii format
  //
  Length = AsciiSPrint (Buffer, sizeof Buffer, "ASSERT %a(%Lu): %a\n",
             FileName, (UINT64)LineNumber, Description);

  //
  // Send the print string to the debug I/O port, if present
  //
  if (PlatformDebugLibIoPortFound ()) {
    IoWriteFifo8 (PcdGet16 (PcdDebugIoPort), Length, Buffer);
  }

  //
  // 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);
}

/**
  Returns TRUE if any one of the bit is set both in ErrorLevel and PcdFixedDebugPrintErrorLevel.

  This function compares the bit mask of ErrorLevel and PcdFixedDebugPrintErrorLevel.

  @retval  TRUE    Current ErrorLevel is supported.
  @retval  FALSE   Current ErrorLevel is not supported.

**/
BOOLEAN
EFIAPI
DebugPrintLevelEnabled (
  IN  CONST UINTN        ErrorLevel
  )
{
  return (BOOLEAN) ((ErrorLevel & PcdGet32(PcdFixedDebugPrintErrorLevel)) != 0);
}

/**
  Return the result of detecting the debug I/O port device.

  @retval TRUE   if the debug I/O port device was detected.
  @retval FALSE  otherwise

**/
BOOLEAN
EFIAPI
PlatformDebugLibIoPortDetect (
  VOID
  )
{
  return IoRead8 (PcdGet16 (PcdDebugIoPort)) == BOCHS_DEBUG_PORT_MAGIC;
}