dumper.c

00001 /* dumper.c -- Dump content of memory.
00002 Copyright 2000, 2001, 2002 Free Software Foundation, Inc.
00003 Written by Stephane Carrez (stcarrez@nerim.fr)
00004 
00005 This file is part of GTAM.
00006 
00007 GTAM is free software; you can redistribute it and/or modify
00008 it under the terms of the GNU General Public License as published by
00009 the Free Software Foundation; either version 2, or (at your option)
00010 any later version.
00011 
00012 GTAM is distributed in the hope that it will be useful,
00013 but WITHOUT ANY WARRANTY; without even the implied warranty of
00014 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
00015 GNU General Public License for more details.
00016 
00017 You should have received a copy of the GNU General Public License
00018 along with GTAM; see the file COPYING. If not, write to
00019 the Free Software Foundation, 59 Temple Place - Suite 330,
00020 Boston, MA 02111-1307, USA. */
00021 
00074 #include <sys/ports.h>
00075 
00076 int __attribute__((noreturn)) main (void);
00077 static unsigned short get_char (void);
00078 void _start (void);
00079 
00080 void
00081 _start ()
00082 {
00083 set_bus_expanded ();
00084 
00085 main ();
00086 }
00087 
00088 /* Write a character on the serial line. */
00089 static void
00090 put_char (unsigned char c)
00091 {
00092 while (!(_io_ports[M6811_SCSR] & M6811_TDRE))
00093 continue;
00094 
00095 _io_ports[M6811_SCDR] = c;
00096 _io_ports[M6811_SCCR2] |= M6811_TE;
00097 }
00098 
00099 /* Write an escaped byte on the serial line. */
00100 static void
00101 put_byte (unsigned char c)
00102 {
00103 /* Don't send \n and escape directly as they may confuse some
00104 synchronisation. */
00105 if (c == '\n' || c == '033円')
00106 {
00107 put_char ('033円');
00108 c ^= 0x20;
00109 }
00110 put_char (c);
00111 }
00112 
00113 static inline void
00114 reboot()
00115 {
00116 #ifndef NO_REBOOT
00117 /* The 'func' type is marked as 'noreturn' to optimize the
00118 generated code. */
00119 typedef void __attribute__ ((noreturn)) (* func)();
00120 
00121 func handler;
00122 
00123 set_bus_single_chip ();
00124 
00125 /* To reboot, get the reset vector and go to the start of the ROM. */
00126 handler = *((func*) 0xbffe);
00127 handler ();
00128 #endif
00129 }
00130 
00131 int
00132 main ()
00133 {
00134 unsigned char* addr;
00135 unsigned char c;
00136 
00137 while (1)
00138 {
00139 /* Print banner for synchronization. */
00140 put_char ('\n');
00141 put_char ('>');
00142 
00143 /* Wait for command. */
00144 c = get_char ();
00145 
00146 /* Read memory command. Command format is:
00147 
00148 R<ADDR-HIGH><ADDR-LOW><SIZE>
00149 
00150 Address and size are passed in binary form.
00151 A size of 0 corresponds to 256 bytes.
00152 
00153 We reply with:
00154 
00155 <SIZE><DATA><CRC>
00156 
00157 where size, data and crc are returned in binary form. */
00158 if (c == 'R')
00159 {
00160 unsigned char size;
00161 unsigned char crc;
00162 
00163 c = get_char ();
00164 addr = (unsigned char*) ((c << 8) | get_char ());
00165 size = get_char ();
00166 
00167 /* Give a feedback about what we are going to send. */
00168 put_byte (size);
00169 
00170 crc = 0;
00171 do
00172 {
00173 c = *addr++;
00174 crc ^= c;
00175 put_byte (c);
00176 }
00177 while (--size != 0);
00178 put_byte (crc);
00179 }
00180 
00181 /* Reboot command. Command format is:
00182 
00183 Z
00184 
00185 We reply with a Z. The final \n is not seen because it is
00186 clobbered during the reboot. */
00187 else if (c == 'Z')
00188 {
00189 put_char (c);
00190 put_char ('\n');
00191 
00192 reboot ();
00193 }
00194 
00195 /* For others, emit something to tell we are alive. */
00196 else
00197 {
00198 put_char ('?');
00199 }
00200 }
00201 }
00202 
00203 #ifndef NO_BREAK
00204 static inline void
00205 restart ()
00206 {
00207 unsigned short i;
00208 volatile unsigned char* ports = &_io_ports[0];
00209 
00210 /* Wait for the transmitter to be ready. */
00211 while (!(ports[M6811_SCSR] & M6811_TDRE))
00212 continue;
00213 
00214 /* Send a break. */
00215 ports[M6811_SCCR2] |= M6811_SBK;
00216 
00217 /* Wait some time (??? is it necessary ???). */
00218 for (i = 1000; --i != 0;)
00219 (void) ports[M6811_TCTN];
00220 
00221 ports[M6811_SCCR2] &= ~M6811_SBK;
00222 
00223 /* Go back to the main with some longjump. We can't go to _start()
00224 because it was clobbered by the ZTMP and ZREG registers. */
00225 __asm__ __volatile__ ("lds #0x0ff");
00226 __asm__ __volatile__ ("bra main");
00227 }
00228 #endif
00229 
00230 static unsigned short
00231 get_char ()
00232 {
00233 unsigned char c;
00234 volatile unsigned char* ports = &_io_ports[0];
00235 
00236 while (1)
00237 {
00238 c = ports[M6811_SCSR];
00239 
00240 #ifndef NO_BREAK
00241 /* If there is a read error or a break, abort everything and
00242 restart. When restarting we send a break so that the host
00243 knows we are restarting. */
00244 if (c & M6811_FE)
00245 restart ();
00246 #endif
00247 
00248 if (c & M6811_RDRF)
00249 break;
00250 }
00251 return ports[M6811_SCDR];
00252 }