contrib/libdcc/dcc_stdio.c

   1 // SPDX-License-Identifier: GPL-2.0-or-later
   2
   3 /***************************************************************************
   4  *   Copyright (C) 2008 by Dominic Rath                                    *
   5  *   Dominic.Rath@gmx.de                                                   *
   6  *   Copyright (C) 2008 by Spencer Oliver                                  *
   7  *   spen@spen-soft.co.uk                                                  *
   8  *   Copyright (C) 2008 by Frederik Kriewtz                                *
   9  *   frederik@kriewitz.eu                                                  *
  10  ***************************************************************************/
  11
  12 #include "dcc_stdio.h"
  13
  14 #define TARGET_REQ_TRACEMSG                                     0x00
  15 #define TARGET_REQ_DEBUGMSG_ASCII                       0x01
  16 #define TARGET_REQ_DEBUGMSG_HEXMSG(size)        (0x01 | ((size & 0xff) << 8))
  17 #define TARGET_REQ_DEBUGCHAR                            0x02
  18
  19 #if defined(__ARM_ARCH_7M__) || defined(__ARM_ARCH_7EM__) || defined(__ARM_ARCH_6SM__)
  20
  21 /* we use the System Control Block DCRDR reg to simulate a arm7_9 dcc channel
  22  * DCRDR[7:0] is used by target for status
  23  * DCRDR[15:8] is used by target for write buffer
  24  * DCRDR[23:16] is used for by host for status
  25  * DCRDR[31:24] is used for by host for write buffer */
  26
  27 #define NVIC_DBG_DATA_R         (*((volatile unsigned short *)0xE000EDF8))
  28
  29 #define BUSY    1
  30
  31 void dbg_write(unsigned long dcc_data)
  32 {
  33         int len = 4;
  34
  35         while (len--)
  36         {
  37                 /* wait for data ready */
  38                 while (NVIC_DBG_DATA_R & BUSY);
  39
  40                 /* write our data and set write flag - tell host there is data*/
  41                 NVIC_DBG_DATA_R = (unsigned short)(((dcc_data & 0xff) << 8) | BUSY);
  42                 dcc_data >>= 8;
  43         }
  44 }
  45
  46 #elif defined(__ARM_ARCH_4T__) || defined(__ARM_ARCH_5TE__) || defined(__ARM_ARCH_5T__)
  47
  48 void dbg_write(unsigned long dcc_data)
  49 {
  50         unsigned long dcc_status;
  51
  52         do {
  53                 asm volatile("mrc p14, 0, %0, c0, c0" : "=r" (dcc_status));
  54         } while (dcc_status & 0x2);
  55
  56         asm volatile("mcr p14, 0, %0, c1, c0" : : "r" (dcc_data));
  57 }
  58
  59 #else
  60  #error unsupported target
  61 #endif
  62
  63 void dbg_trace_point(unsigned long number)
  64 {
  65         dbg_write(TARGET_REQ_TRACEMSG | (number << 8));
  66 }
  67
  68 void dbg_write_u32(const unsigned long *val, long len)
  69 {
  70         dbg_write(TARGET_REQ_DEBUGMSG_HEXMSG(4) | ((len & 0xffff) << 16));
  71
  72         while (len > 0)
  73         {
  74                 dbg_write(*val);
  75
  76                 val++;
  77                 len--;
  78         }
  79 }
  80
  81 void dbg_write_u16(const unsigned short *val, long len)
  82 {
  83         unsigned long dcc_data;
  84
  85         dbg_write(TARGET_REQ_DEBUGMSG_HEXMSG(2) | ((len & 0xffff) << 16));
  86
  87         while (len > 0)
  88         {
  89                 dcc_data = val[0]
  90                         | ((len > 1) ? val[1] << 16: 0x0000);
  91
  92                 dbg_write(dcc_data);
  93
  94                 val += 2;
  95                 len -= 2;
  96         }
  97 }
  98
  99 void dbg_write_u8(const unsigned char *val, long len)
 100 {
 101         unsigned long dcc_data;
 102
 103         dbg_write(TARGET_REQ_DEBUGMSG_HEXMSG(1) | ((len & 0xffff) << 16));
 104
 105         while (len > 0)
 106         {
 107                 dcc_data = val[0]
 108                         | ((len > 1) ? val[1] << 8 : 0x00)
 109                         | ((len > 2) ? val[2] << 16 : 0x00)
 110                         | ((len > 3) ? val[3] << 24 : 0x00);
 111
 112                 dbg_write(dcc_data);
 113
 114                 val += 4;
 115                 len -= 4;
 116         }
 117 }
 118
 119 void dbg_write_str(const char *msg)
 120 {
 121         long len;
 122         unsigned long dcc_data;
 123
 124         for (len = 0; msg[len] && (len < 65536); len++);
 125
 126         dbg_write(TARGET_REQ_DEBUGMSG_ASCII | ((len & 0xffff) << 16));
 127
 128         while (len > 0)
 129         {
 130                 dcc_data = msg[0]
 131                         | ((len > 1) ? msg[1] << 8 : 0x00)
 132                         | ((len > 2) ? msg[2] << 16 : 0x00)
 133                         | ((len > 3) ? msg[3] << 24 : 0x00);
 134                 dbg_write(dcc_data);
 135
 136                 msg += 4;
 137                 len -= 4;
 138         }
 139 }
 140
 141 void dbg_write_char(char msg)
 142 {
 143         dbg_write(TARGET_REQ_DEBUGCHAR | ((msg & 0xff) << 16));
 144 }