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      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 available
     98   @return FALSE - Character not available
     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 
    188