EmbeddedPkg/Library/GdbSerialDebugPortLib/GdbSerialDebugPortLib.c

   1 /** @file
   2   Basic serial IO abstaction for GDB
   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/GdbSerialLib.h>
  18 #include <Library/PcdLib.h>
  19 #include <Library/IoLib.h>
  20 #include <Library/DebugLib.h>
  21 #include <Library/UefiBootServicesTableLib.h>
  22
  23 #include <Protocol/DebugPort.h>
  24
  25
  26 EFI_DEBUGPORT_PROTOCOL  *gDebugPort = NULL;
  27 UINTN                   gTimeOut = 0;
  28
  29 /**
  30   The constructor function initializes the UART.
  31
  32   @param  ImageHandle   The firmware allocated handle for the EFI image.
  33   @param  SystemTable   A pointer to the EFI System Table.
  34
  35   @retval EFI_SUCCESS   The constructor always returns EFI_SUCCESS.
  36
  37 **/
  38 RETURN_STATUS
  39 EFIAPI
  40 GdbSerialLibDebugPortConstructor (
  41   IN EFI_HANDLE        ImageHandle,
  42   IN EFI_SYSTEM_TABLE  *SystemTable
  43   )
  44 {
  45   EFI_STATUS    Status;
  46
  47   Status = gBS->LocateProtocol (&gEfiDebugPortProtocolGuid, NULL, (VOID **)&gDebugPort);
  48   if (!EFI_ERROR (Status)) {
  49     gTimeOut = PcdGet32 (PcdGdbMaxPacketRetryCount);
  50     gDebugPort->Reset (gDebugPort);
  51   }
  52
  53   return Status;
  54 }
  55
  56
  57
  58 /**
  59   Sets the baud rate, receive FIFO depth, transmit/receice time out, parity,
  60   data buts, and stop bits on a serial device. This call is optional as the serial
  61   port will be set up with defaults base on PCD values.
  62
  63   @param  BaudRate         The requested baud rate. A BaudRate value of 0 will use the the
  64                            device's default interface speed.
  65   @param  Parity           The type of parity to use on this serial device. A Parity value of
  66                            DefaultParity will use the device's default parity value.
  67   @param  DataBits         The number of data bits to use on the serial device. A DataBits
  68                            vaule of 0 will use the device's default data bit setting.
  69   @param  StopBits         The number of stop bits to use on this serial device. A StopBits
  70                            value of DefaultStopBits will use the device's default number of
  71                            stop bits.
  72
  73   @retval EFI_SUCCESS      The device was configured.
  74   @retval EFI_DEVICE_ERROR The serial device could not be coonfigured.
  75
  76 **/
  77 RETURN_STATUS
  78 EFIAPI
  79 GdbSerialInit (
  80   IN UINT64     BaudRate,
  81   IN UINT8      Parity,
  82   IN UINT8      DataBits,
  83   IN UINT8      StopBits
  84   )
  85 {
  86   EFI_STATUS  Status;
  87
  88   Status = gDebugPort->Reset (gDebugPort);
  89   return Status;
  90 }
  91
  92
  93 /**
  94   Check to see if a character is available from GDB. Do not read the character as that is
  95   done via GdbGetChar().
  96
  97   @return TRUE  - Character availible
  98   @return FALSE - Character not availible
  99
 100 **/
 101 BOOLEAN
 102 EFIAPI
 103 GdbIsCharAvailable (
 104   VOID
 105   )
 106 {
 107   EFI_STATUS  Status;
 108
 109   Status = gDebugPort->Poll (gDebugPort);
 110
 111   return (Status == EFI_SUCCESS ? TRUE : FALSE);
 112 }
 113
 114
 115 /**
 116   Get a character from GDB. This function must be able to run in interrupt context.
 117
 118   @return A character from GDB
 119
 120 **/
 121 CHAR8
 122 EFIAPI
 123 GdbGetChar (
 124   VOID
 125   )
 126 {
 127   EFI_STATUS  Status;
 128   CHAR8       Char;
 129   UINTN       BufferSize;
 130
 131   do {
 132     BufferSize = sizeof (Char);
 133     Status = gDebugPort->Read (gDebugPort, gTimeOut, &BufferSize, &Char);
 134   } while (EFI_ERROR (Status) || BufferSize != sizeof (Char));
 135
 136   return Char;
 137 }
 138
 139
 140 /**
 141   Send a character to GDB. This function must be able to run in interrupt context.
 142
 143
 144   @param  Char    Send a character to GDB
 145
 146 **/
 147
 148 VOID
 149 EFIAPI
 150 GdbPutChar (
 151   IN  CHAR8   Char
 152   )
 153 {
 154   EFI_STATUS  Status;
 155   UINTN       BufferSize;
 156
 157   do {
 158     BufferSize = sizeof (Char);
 159     Status = gDebugPort->Write (gDebugPort, gTimeOut, &BufferSize, &Char);
 160   } while (EFI_ERROR (Status) || BufferSize != sizeof (Char));
 161
 162   return;
 163 }
 164
 165 /**
 166   Send an ASCII string to GDB. This function must be able to run in interrupt context.
 167
 168
 169   @param  String    Send a string to GDB
 170
 171 **/
 172
 173 VOID
 174 GdbPutString (
 175   IN CHAR8  *String
 176   )
 177 {
 178  // We could performance enhance this function by calling gDebugPort->Write ()
 179   while (*String != '\0') {
 180     GdbPutChar (*String);
 181     String++;
 182   }
 183 }
 184
 185
 186
 187