ArmPlatformPkg/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 #include <Drivers/PL011Uart.h>
  21
  22 RETURN_STATUS
  23 EFIAPI
  24 GdbSerialLibConstructor (
  25   VOID
  26   )
  27 {
  28   return GdbSerialInit (115200, 0, 8, 1);
  29 }
  30
  31 RETURN_STATUS
  32 EFIAPI
  33 GdbSerialInit (
  34   IN UINT64     BaudRate,
  35   IN UINT8      Parity,
  36   IN UINT8      DataBits,
  37   IN UINT8      StopBits
  38   )
  39 {
  40   if ((Parity != 0) || (DataBits != 8) || (StopBits != 1)) {
  41     return RETURN_UNSUPPORTED;
  42   }
  43
  44   if (BaudRate != 115200) {
  45     // Could add support for different Baud rates....
  46     return RETURN_UNSUPPORTED;
  47   }
  48
  49   UINT32  Base = PcdGet32 (PcdGdbUartBase);
  50
  51   // initialize baud rate generator to 115200 based on EB clock REFCLK24MHZ
  52   MmioWrite32 (Base + UARTIBRD, UART_115200_IDIV);
  53   MmioWrite32 (Base + UARTFBRD, UART_115200_FDIV);
  54
  55   // no parity, 1 stop, no fifo, 8 data bits
  56   MmioWrite32 (Base + UARTLCR_H, 0x60);
  57
  58   // clear any pending errors
  59   MmioWrite32 (Base + UARTECR, 0);
  60
  61   // enable tx, rx, and uart overall
  62   MmioWrite32 (Base + UARTCR, 0x301);
  63
  64   return RETURN_SUCCESS;
  65 }
  66
  67 BOOLEAN
  68 EFIAPI
  69 GdbIsCharAvailable (
  70   VOID
  71   )
  72 {
  73   UINT32 FR = PcdGet32 (PcdGdbUartBase) + UARTFR;
  74
  75   if ((MmioRead32 (FR) & UART_RX_EMPTY_FLAG_MASK) == 0) {
  76     return TRUE;
  77   } else {
  78     return FALSE;
  79   }
  80 }
  81
  82 CHAR8
  83 EFIAPI
  84 GdbGetChar (
  85   VOID
  86   )
  87 {
  88   UINT32  FR = PcdGet32 (PcdGdbUartBase) + UARTFR;
  89   UINT32  DR = PcdGet32 (PcdGdbUartBase) + UARTDR;
  90
  91   while ((MmioRead32 (FR) & UART_RX_EMPTY_FLAG_MASK) == 0);
  92   return MmioRead8 (DR);
  93 }
  94
  95 VOID
  96 EFIAPI
  97 GdbPutChar (
  98   IN  CHAR8   Char
  99   )
 100 {
 101   UINT32 FR = PcdGet32 (PcdGdbUartBase) + UARTFR;
 102   UINT32 DR = PcdGet32 (PcdGdbUartBase) + UARTDR;
 103
 104   while ((MmioRead32 (FR) & UART_TX_EMPTY_FLAG_MASK) != 0);
 105   MmioWrite8 (DR, Char);
 106   return;
 107 }
 108
 109 VOID
 110 GdbPutString (
 111   IN CHAR8  *String
 112   )
 113 {
 114   while (*String != '\0') {
 115     GdbPutChar (*String);
 116     String++;
 117   }
 118 }