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      1 /** @file
      2   Serial I/O Port library functions with no library constructor/destructor
      3 
      4   Copyright (c) 2008 - 2009, Apple Inc. All rights reserved.<BR>
      5 
      6   This program and the accompanying materials
      7   are licensed and made available under the terms and conditions of the BSD License
      8   which accompanies this distribution.  The full text of the license may be found at
      9   http://opensource.org/licenses/bsd-license.php
     10 
     11   THE PROGRAM IS DISTRIBUTED UNDER THE BSD LICENSE ON AN "AS IS" BASIS,
     12   WITHOUT WARRANTIES OR REPRESENTATIONS OF ANY KIND, EITHER EXPRESS OR IMPLIED.
     13 
     14 **/
     15 
     16 #include <Uefi.h>
     17 #include <Library/DebugLib.h>
     18 #include <Library/SemihostLib.h>
     19 #include <Library/SerialPortLib.h>
     20 
     21 
     22 /*
     23 
     24   Programmed hardware of Serial port.
     25 
     26   @return    Always return EFI_UNSUPPORTED.
     27 
     28 **/
     29 RETURN_STATUS
     30 EFIAPI
     31 SerialPortInitialize (
     32   VOID
     33   )
     34 {
     35   if (SemihostConnectionSupported ()) {
     36     return RETURN_SUCCESS;
     37   } else {
     38     return RETURN_UNSUPPORTED;
     39   }
     40 }
     41 
     42 /**
     43   Write data to serial device.
     44 
     45   @param  Buffer           Point of data buffer which need to be writed.
     46   @param  NumberOfBytes    Number of output bytes which are cached in Buffer.
     47 
     48   @retval 0                Write data failed.
     49   @retval !0               Actual number of bytes writed to serial device.
     50 
     51 **/
     52 
     53 #define PRINT_BUFFER_SIZE       512
     54 #define PRINT_BUFFER_THRESHOLD  (PRINT_BUFFER_SIZE - 4)
     55 
     56 UINTN
     57 EFIAPI
     58 SerialPortWrite (
     59   IN UINT8     *Buffer,
     60   IN UINTN     NumberOfBytes
     61 )
     62 {
     63   UINT8 PrintBuffer[PRINT_BUFFER_SIZE];
     64   UINTN SourceIndex      = 0;
     65   UINTN DestinationIndex = 0;
     66   UINT8 CurrentCharacter;
     67 
     68   while (SourceIndex < NumberOfBytes)
     69   {
     70       CurrentCharacter = Buffer[SourceIndex++];
     71 
     72       switch (CurrentCharacter)
     73       {
     74       case '\r':
     75           continue;
     76 
     77       case '\n':
     78           PrintBuffer[DestinationIndex++] = ' ';
     79           // fall through
     80 
     81       default:
     82           PrintBuffer[DestinationIndex++] = CurrentCharacter;
     83           break;
     84       }
     85 
     86       if (DestinationIndex > PRINT_BUFFER_THRESHOLD)
     87       {
     88           PrintBuffer[DestinationIndex] = '\0';
     89           SemihostWriteString ((CHAR8 *) PrintBuffer);
     90 
     91           DestinationIndex = 0;
     92       }
     93   }
     94 
     95   if (DestinationIndex > 0)
     96   {
     97       PrintBuffer[DestinationIndex] = '\0';
     98       SemihostWriteString ((CHAR8 *) PrintBuffer);
     99   }
    100 
    101   return NumberOfBytes;
    102 }
    103 
    104 
    105 /**
    106   Read data from serial device and save the datas in buffer.
    107 
    108   @param  Buffer           Point of data buffer which need to be writed.
    109   @param  NumberOfBytes    Number of output bytes which are cached in Buffer.
    110 
    111   @retval 0                Read data failed.
    112   @retval !0               Aactual number of bytes read from serial device.
    113 
    114 **/
    115 UINTN
    116 EFIAPI
    117 SerialPortRead (
    118   OUT UINT8     *Buffer,
    119   IN  UINTN     NumberOfBytes
    120 )
    121 {
    122   *Buffer = SemihostReadCharacter ();
    123   return 1;
    124 }
    125 
    126 
    127 
    128 /**
    129   Check to see if any data is avaiable to be read from the debug device.
    130 
    131   @retval TRUE       At least one byte of data is avaiable to be read
    132   @retval FALSE      No data is avaiable to be read
    133 
    134 **/
    135 BOOLEAN
    136 EFIAPI
    137 SerialPortPoll (
    138   VOID
    139   )
    140 {
    141   // Since SemiHosting read character is blocking always say we have a char ready?
    142   return SemihostConnectionSupported ();
    143 }
    144 
    145