ArmRealViewEbPkg/Library/GdbSerialLib/GdbSerialLib.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
  21 #include <ArmEb/ArmEb.h>
  22
  23 RETURN_STATUS
  24 EFIAPI
  25 GdbSerialLibConstructor (
  26   VOID
  27   )
  28 {
  29   return GdbSerialInit (115200, 0, 8, 1);
  30 }
  31
  32 RETURN_STATUS
  33 EFIAPI
  34 GdbSerialInit (
  35   IN UINT64     BaudRate,
  36   IN UINT8      Parity,
  37   IN UINT8      DataBits,
  38   IN UINT8      StopBits
  39   )
  40 {
  41   if ((Parity != 0) || (DataBits != 8) || (StopBits != 1)) {
  42     return RETURN_UNSUPPORTED;
  43   }
  44
  45   if (BaudRate != 115200) {
  46     // Could add support for different Baud rates....
  47     return RETURN_UNSUPPORTED;
  48   }
  49
  50   UINT32  Base = PcdGet32 (PcdGdbUartBase);
  51
  52   // initialize baud rate generator to 115200 based on EB clock REFCLK24MHZ
  53   MmioWrite32 (Base + UARTIBRD, UART_115200_IDIV);
  54   MmioWrite32 (Base + UARTFBRD, UART_115200_FDIV);
  55
  56   // no parity, 1 stop, no fifo, 8 data bits
  57   MmioWrite32 (Base + UARTLCR_H, 0x60);
  58
  59   // clear any pending errors
  60   MmioWrite32 (Base + UARTECR, 0);
  61
  62   // enable tx, rx, and uart overall
  63   MmioWrite32 (Base + UARTCR, 0x301);
  64
  65   return RETURN_SUCCESS;
  66 }
  67
  68 BOOLEAN
  69 EFIAPI
  70 GdbIsCharAvailable (
  71   VOID
  72   )
  73 {
  74   UINT32 FR = PcdGet32 (PcdGdbUartBase) + UARTFR;
  75
  76   if ((MmioRead32 (FR) & UART_RX_EMPTY_FLAG_MASK) == 0) {
  77     return TRUE;
  78   } else {
  79     return FALSE;
  80   }
  81 }
  82
  83 CHAR8
  84 EFIAPI
  85 GdbGetChar (
  86   VOID
  87   )
  88 {
  89   UINT32  FR = PcdGet32 (PcdGdbUartBase) + UARTFR;
  90   UINT32  DR = PcdGet32 (PcdGdbUartBase) + UARTDR;
  91
  92   while ((MmioRead32 (FR) & UART_RX_EMPTY_FLAG_MASK) == 0);
  93   return MmioRead8 (DR);
  94 }
  95
  96 VOID
  97 EFIAPI
  98 GdbPutChar (
  99   IN  CHAR8   Char
 100   )
 101 {
 102   UINT32 FR = PcdGet32 (PcdGdbUartBase) + UARTFR;
 103   UINT32 DR = PcdGet32 (PcdGdbUartBase) + UARTDR;
 104
 105   while ((MmioRead32 (FR) & UART_TX_EMPTY_FLAG_MASK) != 0);
 106   MmioWrite8 (DR, Char);
 107   return;
 108 }
 109
 110 VOID
 111 GdbPutString (
 112   IN CHAR8  *String
 113   )
 114 {
 115   while (*String != '\0') {
 116     GdbPutChar (*String);
 117     String++;
 118   }
 119 }
 120
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 123