SourceLevelDebugPkg/Library/DebugCommunicationLibSerialPort/DebugCommunicationLibSerialPort.c

   1 /** @file
   2   Debug Port Library implementation based on serial port.
   3
   4   Copyright (c) 2010 - 2018, Intel Corporation. All rights reserved.<BR>
   5   SPDX-License-Identifier: BSD-2-Clause-Patent
   6
   7 **/
   8
   9 #include <Base.h>
  10
  11 #include <Library/DebugCommunicationLib.h>
  12 #include <Library/SerialPortLib.h>
  13 #include <Library/DebugLib.h>
  14
  15 /**
  16   Initialize the debug port.
  17
  18   This function will initialize debug port to get it ready for data transmission. If
  19   certain Debug Communication Library instance has to save some private data in the
  20   stack, this function must work on the mode that doesn't return to the caller, then
  21   the caller needs to wrap up all rest of logic after DebugPortInitialize() into one
  22   function and pass it into DebugPortInitialize(). DebugPortInitialize() is
  23   responsible to invoke the passing-in function at the end of DebugPortInitialize().
  24
  25   If the parameter Function is not NULL, Debug Communication Library instance will
  26   invoke it by passing in the Context to be the first parameter. Debug Communication
  27   Library instance could create one debug port handle to be the second parameter
  28   passing into the Function. Debug Communication Library instance also could pass
  29   NULL to be the second parameter if it doesn't create the debug port handle.
  30
  31   If the parameter Function is NULL, and Context is not NULL. At this time, Context
  32   is the debug port handle created by the previous Debug Communication Library
  33   instance.
  34   a) If the instance can understand and continue use the private data of the previous
  35      instance, it could return the same handle as passed in (as Context parameter).
  36   b) If the instance does not understand, or does not want to continue use the
  37      private data of the previous instance, it could ignore the input Context parameter
  38      and create the new handle to be returned.
  39
  40   If Function() is NULL and Context is NULL, Debug Communication Library could create a
  41   new handle and return it. NULL is also a valid handle to be returned.
  42
  43   @param[in] Context      Context needed by callback function; it was optional.
  44   @param[in] Function     Continue function called by Debug Communication library;
  45                           it was optional.
  46
  47   @return  The debug port handle created by Debug Communication Library if Function
  48            is not NULL.
  49
  50 **/
  51 DEBUG_PORT_HANDLE
  52 EFIAPI
  53 DebugPortInitialize (
  54   IN VOID                 *Context,
  55   IN DEBUG_PORT_CONTINUE  Function
  56   )
  57 {
  58   RETURN_STATUS  Status;
  59
  60   Status = SerialPortInitialize ();
  61   if (RETURN_ERROR (Status)) {
  62     DEBUG ((DEBUG_ERROR, "Debug Serial Port: Initialization failed!\n"));
  63   }
  64
  65   if (Function != NULL) {
  66     Function (Context, NULL);
  67   }
  68
  69   return NULL;
  70 }
  71
  72 /**
  73   Read data from debug device and save the data in a buffer.
  74
  75   Reads NumberOfBytes data bytes from a debug device into the buffer
  76   specified by Buffer. The number of bytes actually read is returned.
  77   If the return value is less than NumberOfBytes, then the rest operation failed.
  78   If NumberOfBytes is zero, then return 0.
  79
  80   @param  Handle           Debug port handle.
  81   @param  Buffer           Pointer to the data buffer to store the data read from the debug device.
  82   @param  NumberOfBytes    Number of bytes which will be read.
  83   @param  Timeout          Timeout value for reading from debug device. It unit is Microsecond.
  84
  85   @retval 0                Read data failed, no data is to be read.
  86   @retval >0               Actual number of bytes read from debug device.
  87
  88 **/
  89 UINTN
  90 EFIAPI
  91 DebugPortReadBuffer (
  92   IN DEBUG_PORT_HANDLE  Handle,
  93   IN UINT8              *Buffer,
  94   IN UINTN              NumberOfBytes,
  95   IN UINTN              Timeout
  96   )
  97 {
  98   if ((NumberOfBytes != 1) || (Buffer == NULL) || (Timeout != 0)) {
  99     return 0;
 100   }
 101
 102   return SerialPortRead (Buffer, 1);
 103 }
 104
 105 /**
 106   Write data from buffer to debug device.
 107
 108   Writes NumberOfBytes data bytes from Buffer to the debug device.
 109   The number of bytes actually written to the debug device is returned.
 110   If the return value is less than NumberOfBytes, then the write operation failed.
 111   If NumberOfBytes is zero, then return 0.
 112
 113   @param  Handle           Debug port handle.
 114   @param  Buffer           Pointer to the data buffer to be written.
 115   @param  NumberOfBytes    Number of bytes to written to the debug device.
 116
 117   @retval 0                NumberOfBytes is 0.
 118   @retval >0               The number of bytes written to the debug device.
 119                            If this value is less than NumberOfBytes, then the read operation failed.
 120
 121 **/
 122 UINTN
 123 EFIAPI
 124 DebugPortWriteBuffer (
 125   IN DEBUG_PORT_HANDLE  Handle,
 126   IN UINT8              *Buffer,
 127   IN UINTN              NumberOfBytes
 128   )
 129 {
 130   return SerialPortWrite (Buffer, NumberOfBytes);
 131 }
 132
 133 /**
 134   Polls a debug device to see if there is any data waiting to be read.
 135
 136   Polls a debug device to see if there is any data waiting to be read.
 137   If there is data waiting to be read from the debug device, then TRUE is returned.
 138   If there is no data waiting to be read from the debug device, then FALSE is returned.
 139
 140   @param  Handle           Debug port handle.
 141
 142   @retval TRUE             Data is waiting to be read from the debug device.
 143   @retval FALSE            There is no data waiting to be read from the serial device.
 144
 145 **/
 146 BOOLEAN
 147 EFIAPI
 148 DebugPortPollBuffer (
 149   IN DEBUG_PORT_HANDLE  Handle
 150   )
 151 {
 152   return SerialPortPoll ();
 153 }