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   SPDX-License-Identifier: BSD-2-Clause-Patent
   7
   8 **/
   9
  10 #include <Uefi.h>
  11 #include <Library/GdbSerialLib.h>
  12 #include <Library/PcdLib.h>
  13 #include <Library/IoLib.h>
  14 #include <Library/DebugLib.h>
  15 #include <Library/UefiBootServicesTableLib.h>
  16
  17 #include <Protocol/DebugPort.h>
  18
  19
  20 EFI_DEBUGPORT_PROTOCOL  *gDebugPort = NULL;
  21 UINTN                   gTimeOut = 0;
  22
  23 /**
  24   The constructor function initializes the UART.
  25
  26   @param  ImageHandle   The firmware allocated handle for the EFI image.
  27   @param  SystemTable   A pointer to the EFI System Table.
  28
  29   @retval EFI_SUCCESS   The constructor always returns EFI_SUCCESS.
  30
  31 **/
  32 RETURN_STATUS
  33 EFIAPI
  34 GdbSerialLibDebugPortConstructor (
  35   IN EFI_HANDLE        ImageHandle,
  36   IN EFI_SYSTEM_TABLE  *SystemTable
  37   )
  38 {
  39   EFI_STATUS    Status;
  40
  41   Status = gBS->LocateProtocol (&gEfiDebugPortProtocolGuid, NULL, (VOID **)&gDebugPort);
  42   if (!EFI_ERROR (Status)) {
  43     gTimeOut = PcdGet32 (PcdGdbMaxPacketRetryCount);
  44     gDebugPort->Reset (gDebugPort);
  45   }
  46
  47   return Status;
  48 }
  49
  50
  51
  52 /**
  53   Sets the baud rate, receive FIFO depth, transmit/receice time out, parity,
  54   data buts, and stop bits on a serial device. This call is optional as the serial
  55   port will be set up with defaults base on PCD values.
  56
  57   @param  BaudRate         The requested baud rate. A BaudRate value of 0 will use the the
  58                            device's default interface speed.
  59   @param  Parity           The type of parity to use on this serial device. A Parity value of
  60                            DefaultParity will use the device's default parity value.
  61   @param  DataBits         The number of data bits to use on the serial device. A DataBits
  62                            vaule of 0 will use the device's default data bit setting.
  63   @param  StopBits         The number of stop bits to use on this serial device. A StopBits
  64                            value of DefaultStopBits will use the device's default number of
  65                            stop bits.
  66
  67   @retval EFI_SUCCESS      The device was configured.
  68   @retval EFI_DEVICE_ERROR The serial device could not be coonfigured.
  69
  70 **/
  71 RETURN_STATUS
  72 EFIAPI
  73 GdbSerialInit (
  74   IN UINT64     BaudRate,
  75   IN UINT8      Parity,
  76   IN UINT8      DataBits,
  77   IN UINT8      StopBits
  78   )
  79 {
  80   EFI_STATUS  Status;
  81
  82   Status = gDebugPort->Reset (gDebugPort);
  83   return Status;
  84 }
  85
  86
  87 /**
  88   Check to see if a character is available from GDB. Do not read the character as that is
  89   done via GdbGetChar().
  90
  91   @return TRUE  - Character available
  92   @return FALSE - Character not available
  93
  94 **/
  95 BOOLEAN
  96 EFIAPI
  97 GdbIsCharAvailable (
  98   VOID
  99   )
 100 {
 101   EFI_STATUS  Status;
 102
 103   Status = gDebugPort->Poll (gDebugPort);
 104
 105   return (Status == EFI_SUCCESS ? TRUE : FALSE);
 106 }
 107
 108
 109 /**
 110   Get a character from GDB. This function must be able to run in interrupt context.
 111
 112   @return A character from GDB
 113
 114 **/
 115 CHAR8
 116 EFIAPI
 117 GdbGetChar (
 118   VOID
 119   )
 120 {
 121   EFI_STATUS  Status;
 122   CHAR8       Char;
 123   UINTN       BufferSize;
 124
 125   do {
 126     BufferSize = sizeof (Char);
 127     Status = gDebugPort->Read (gDebugPort, gTimeOut, &BufferSize, &Char);
 128   } while (EFI_ERROR (Status) || BufferSize != sizeof (Char));
 129
 130   return Char;
 131 }
 132
 133
 134 /**
 135   Send a character to GDB. This function must be able to run in interrupt context.
 136
 137
 138   @param  Char    Send a character to GDB
 139
 140 **/
 141
 142 VOID
 143 EFIAPI
 144 GdbPutChar (
 145   IN  CHAR8   Char
 146   )
 147 {
 148   EFI_STATUS  Status;
 149   UINTN       BufferSize;
 150
 151   do {
 152     BufferSize = sizeof (Char);
 153     Status = gDebugPort->Write (gDebugPort, gTimeOut, &BufferSize, &Char);
 154   } while (EFI_ERROR (Status) || BufferSize != sizeof (Char));
 155
 156   return;
 157 }
 158
 159 /**
 160   Send an ASCII string to GDB. This function must be able to run in interrupt context.
 161
 162
 163   @param  String    Send a string to GDB
 164
 165 **/
 166
 167 VOID
 168 GdbPutString (
 169   IN CHAR8  *String
 170   )
 171 {
 172  // We could performance enhance this function by calling gDebugPort->Write ()
 173   while (*String != '\0') {
 174     GdbPutChar (*String);
 175     String++;
 176   }
 177 }
 178
 179
 180
 181