EmbeddedPkg/Library/GdbSerialDebugPortLib/GdbSerialDebugPortLib.c

   1 /** @file
   2   Basic serial IO abstraction 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 EFI_DEBUGPORT_PROTOCOL  *gDebugPort = NULL;
  20 UINT32                  gTimeOut    = 0;
  21
  22 /**
  23   The constructor function initializes the UART.
  24
  25   @param  ImageHandle   The firmware allocated handle for the EFI image.
  26   @param  SystemTable   A pointer to the EFI System Table.
  27
  28   @retval EFI_SUCCESS   The constructor always returns EFI_SUCCESS.
  29
  30 **/
  31 RETURN_STATUS
  32 EFIAPI
  33 GdbSerialLibDebugPortConstructor (
  34   IN EFI_HANDLE        ImageHandle,
  35   IN EFI_SYSTEM_TABLE  *SystemTable
  36   )
  37 {
  38   EFI_STATUS  Status;
  39
  40   Status = gBS->LocateProtocol (&gEfiDebugPortProtocolGuid, NULL, (VOID **)&gDebugPort);
  41   if (!EFI_ERROR (Status)) {
  42     gTimeOut = PcdGet32 (PcdGdbMaxPacketRetryCount);
  43     gDebugPort->Reset (gDebugPort);
  44   }
  45
  46   return Status;
  47 }
  48
  49 /**
  50   Sets the baud rate, receive FIFO depth, transmit/receive time out, parity,
  51   data buts, and stop bits on a serial device. This call is optional as the serial
  52   port will be set up with defaults base on PCD values.
  53
  54   @param  BaudRate         The requested baud rate. A BaudRate value of 0 will use the
  55                            device's default interface speed.
  56   @param  Parity           The type of parity to use on this serial device. A Parity value of
  57                            DefaultParity will use the device's default parity value.
  58   @param  DataBits         The number of data bits to use on the serial device. A DataBits
  59                            value of 0 will use the device's default data bit setting.
  60   @param  StopBits         The number of stop bits to use on this serial device. A StopBits
  61                            value of DefaultStopBits will use the device's default number of
  62                            stop bits.
  63
  64   @retval EFI_SUCCESS      The device was configured.
  65   @retval EFI_DEVICE_ERROR The serial device could not be configured.
  66
  67 **/
  68 RETURN_STATUS
  69 EFIAPI
  70 GdbSerialInit (
  71   IN UINT64  BaudRate,
  72   IN UINT8   Parity,
  73   IN UINT8   DataBits,
  74   IN UINT8   StopBits
  75   )
  76 {
  77   EFI_STATUS  Status;
  78
  79   Status = gDebugPort->Reset (gDebugPort);
  80   return Status;
  81 }
  82
  83 /**
  84   Check to see if a character is available from GDB. Do not read the character as that is
  85   done via GdbGetChar().
  86
  87   @return TRUE  - Character available
  88   @return FALSE - Character not available
  89
  90 **/
  91 BOOLEAN
  92 EFIAPI
  93 GdbIsCharAvailable (
  94   VOID
  95   )
  96 {
  97   EFI_STATUS  Status;
  98
  99   Status = gDebugPort->Poll (gDebugPort);
 100
 101   return (Status == EFI_SUCCESS ? TRUE : FALSE);
 102 }
 103
 104 /**
 105   Get a character from GDB. This function must be able to run in interrupt context.
 106
 107   @return A character from GDB
 108
 109 **/
 110 CHAR8
 111 EFIAPI
 112 GdbGetChar (
 113   VOID
 114   )
 115 {
 116   EFI_STATUS  Status;
 117   CHAR8       Char;
 118   UINTN       BufferSize;
 119
 120   do {
 121     BufferSize = sizeof (Char);
 122     Status     = gDebugPort->Read (gDebugPort, gTimeOut, &BufferSize, &Char);
 123   } while (EFI_ERROR (Status) || BufferSize != sizeof (Char));
 124
 125   return Char;
 126 }
 127
 128 /**
 129   Send a character to GDB. This function must be able to run in interrupt context.
 130
 131
 132   @param  Char    Send a character to GDB
 133
 134 **/
 135 VOID
 136 EFIAPI
 137 GdbPutChar (
 138   IN  CHAR8  Char
 139   )
 140 {
 141   EFI_STATUS  Status;
 142   UINTN       BufferSize;
 143
 144   do {
 145     BufferSize = sizeof (Char);
 146     Status     = gDebugPort->Write (gDebugPort, gTimeOut, &BufferSize, &Char);
 147   } while (EFI_ERROR (Status) || BufferSize != sizeof (Char));
 148
 149   return;
 150 }
 151
 152 /**
 153   Send an ASCII string to GDB. This function must be able to run in interrupt context.
 154
 155
 156   @param  String    Send a string to GDB
 157
 158 **/
 159 VOID
 160 GdbPutString (
 161   IN CHAR8  *String
 162   )
 163 {
 164   // We could performance enhance this function by calling gDebugPort->Write ()
 165   while (*String != '\0') {
 166     GdbPutChar (*String);
 167     String++;
 168   }
 169 }