1 /*- 2 * Copyright (c) 2004 Marcel Moolenaar 3 * All rights reserved. 4 * 5 * Redistribution and use in source and binary forms, with or without 6 * modification, are permitted provided that the following conditions 7 * are met: 8 * 9 * 1. Redistributions of source code must retain the above copyright 10 * notice, this list of conditions and the following disclaimer. 11 * 2. Redistributions in binary form must reproduce the above copyright 12 * notice, this list of conditions and the following disclaimer in the 13 * documentation and/or other materials provided with the distribution. 14 * 15 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR 16 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES 17 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. 18 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, 19 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT 20 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, 21 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY 22 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT 23 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF 24 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. 25 */ 26 27 #include <sys/cdefs.h> 28 __FBSDID("$FreeBSD$"); 29 30 #include <sys/param.h> 31 #include <sys/systm.h> 32 #include <sys/ctype.h> 33 #include <sys/kdb.h> 34 35 #include <machine/gdb_machdep.h> 36 37 #include <gdb/gdb.h> 38 #include <gdb/gdb_int.h> 39 40 static char gdb_rxbuf[GDB_BUFSZ]; 41 char *gdb_rxp = NULL; 42 size_t gdb_rxsz = 0; 43 static char gdb_txbuf[GDB_BUFSZ]; 44 char *gdb_txp = NULL; /* Used in inline functions. */ 45 46 #define C2N(c) (((c) < 'A') ? (c) - '0' : \ 47 10 + (((c) < 'a') ? (c) - 'A' : (c) - 'a')) 48 #define N2C(n) (((n) < 10) ? (n) + '0' : (n) + 'a' - 10) 49 50 /* 51 * Get a single character 52 */ 53 54 static int 55 gdb_getc(void) 56 { 57 int c; 58 59 do 60 c = gdb_cur->gdb_getc(); 61 while (c == -1); 62 return (c); 63 } 64 65 /* 66 * Functions to receive and extract from a packet. 67 */ 68 69 int 70 gdb_rx_begin(void) 71 { 72 int c, cksum; 73 74 gdb_rxp = NULL; 75 do { 76 /* 77 * Wait for the start character, ignore all others. 78 * XXX needs a timeout. 79 */ 80 while ((c = gdb_getc()) != '$') 81 ; 82 83 /* Read until a # or end of buffer is found. */ 84 cksum = 0; 85 gdb_rxsz = 0; 86 while (gdb_rxsz < sizeof(gdb_rxbuf) - 1) { 87 c = gdb_getc(); 88 if (c == '#') 89 break; 90 gdb_rxbuf[gdb_rxsz++] = c; 91 cksum += c; 92 } 93 gdb_rxbuf[gdb_rxsz] = 0; 94 cksum &= 0xff; 95 96 /* Bail out on a buffer overflow. */ 97 if (c != '#') { 98 gdb_cur->gdb_putc('-'); 99 return (ENOSPC); 100 } 101 102 c = gdb_getc(); 103 cksum -= (C2N(c) << 4) & 0xf0; 104 c = gdb_getc(); 105 cksum -= C2N(c) & 0x0f; 106 gdb_cur->gdb_putc((cksum == 0) ? '+' : '-'); 107 if (cksum != 0) 108 printf("GDB: packet `%s' has invalid checksum\n", 109 gdb_rxbuf); 110 } while (cksum != 0); 111 112 gdb_rxp = gdb_rxbuf; 113 return (0); 114 } 115 116 int 117 gdb_rx_equal(const char *str) 118 { 119 int len; 120 121 len = strlen(str); 122 if (len > gdb_rxsz || strncmp(str, gdb_rxp, len) != 0) 123 return (0); 124 gdb_rxp += len; 125 gdb_rxsz -= len; 126 return (1); 127 } 128 129 int 130 gdb_rx_mem(unsigned char *addr, size_t size) 131 { 132 void *prev; 133 jmp_buf jb; 134 int ret; 135 unsigned char c; 136 137 if (size * 2 != gdb_rxsz) 138 return (-1); 139 140 prev = kdb_jmpbuf(jb); 141 ret = setjmp(jb); 142 if (ret == 0) { 143 while (size-- > 0) { 144 c = (C2N(gdb_rxp[0]) << 4) & 0xf0; 145 c |= C2N(gdb_rxp[1]) & 0x0f; 146 *addr++ = c; 147 gdb_rxsz -= 2; 148 gdb_rxp += 2; 149 } 150 } 151 (void)kdb_jmpbuf(prev); 152 return ((ret == 0) ? 1 : 0); 153 } 154 155 int 156 gdb_rx_varhex(uintmax_t *vp) 157 { 158 uintmax_t v; 159 int c, neg; 160 161 c = gdb_rx_char(); 162 neg = (c == '-') ? 1 : 0; 163 if (neg == 1) 164 c = gdb_rx_char(); 165 if (!isxdigit(c)) { 166 gdb_rxp -= ((c == -1) ? 0 : 1) + neg; 167 gdb_rxsz += ((c == -1) ? 0 : 1) + neg; 168 return (-1); 169 } 170 v = 0; 171 do { 172 v <<= 4; 173 v += C2N(c); 174 c = gdb_rx_char(); 175 } while (isxdigit(c)); 176 if (c != -1) { 177 gdb_rxp--; 178 gdb_rxsz++; 179 } 180 *vp = (neg) ? -v : v; 181 return (0); 182 } 183 184 /* 185 * Function to build and send a package. 186 */ 187 188 void 189 gdb_tx_begin(char tp) 190 { 191 192 gdb_txp = gdb_txbuf; 193 if (tp != '\0') 194 gdb_tx_char(tp); 195 } 196 197 int 198 gdb_tx_end(void) 199 { 200 const char *p; 201 int runlen; 202 unsigned char c, cksum; 203 204 do { 205 gdb_cur->gdb_putc('$'); 206 207 cksum = 0; 208 p = gdb_txbuf; 209 while (p < gdb_txp) { 210 /* Send a character and start run-length encoding. */ 211 c = *p++; 212 gdb_cur->gdb_putc(c); 213 cksum += c; 214 runlen = 0; 215 /* Determine run-length and update checksum. */ 216 while (p < gdb_txp && *p == c) { 217 runlen++; 218 p++; 219 } 220 /* Emit the run-length encoded string. */ 221 while (runlen >= 97) { 222 gdb_cur->gdb_putc('*'); 223 cksum += '*'; 224 gdb_cur->gdb_putc(97+29); 225 cksum += 97+29; 226 runlen -= 97; 227 if (runlen > 0) { 228 gdb_cur->gdb_putc(c); 229 cksum += c; 230 runlen--; 231 } 232 } 233 if (runlen == 1) { 234 gdb_cur->gdb_putc(c); 235 cksum += c; 236 runlen--; 237 } 238 if (runlen == 0) 239 continue; 240 /* Don't emit '$', '#', '+' or '-'. */ 241 if (runlen == 7) { 242 gdb_cur->gdb_putc(c); 243 cksum += c; 244 runlen--; 245 } 246 if (runlen == 6 || runlen == 14 || runlen == 16) { 247 gdb_cur->gdb_putc(c); 248 cksum += c; 249 runlen--; 250 } 251 gdb_cur->gdb_putc('*'); 252 cksum += '*'; 253 gdb_cur->gdb_putc(runlen+29); 254 cksum += runlen+29; 255 } 256 257 gdb_cur->gdb_putc('#'); 258 c = cksum >> 4; 259 gdb_cur->gdb_putc(N2C(c)); 260 c = cksum & 0x0f; 261 gdb_cur->gdb_putc(N2C(c)); 262 263 c = gdb_getc(); 264 } while (c != '+'); 265 266 return (0); 267 } 268 269 int 270 gdb_tx_mem(const unsigned char *addr, size_t size) 271 { 272 void *prev; 273 jmp_buf jb; 274 int ret; 275 276 prev = kdb_jmpbuf(jb); 277 ret = setjmp(jb); 278 if (ret == 0) { 279 while (size-- > 0) { 280 *gdb_txp++ = N2C(*addr >> 4); 281 *gdb_txp++ = N2C(*addr & 0x0f); 282 addr++; 283 } 284 } 285 (void)kdb_jmpbuf(prev); 286 return ((ret == 0) ? 1 : 0); 287 } 288 289 void 290 gdb_tx_reg(int regnum) 291 { 292 unsigned char *regp; 293 size_t regsz; 294 295 regp = gdb_cpu_getreg(regnum, ®sz); 296 if (regp == NULL) { 297 /* Register unavailable. */ 298 while (regsz--) { 299 gdb_tx_char('x'); 300 gdb_tx_char('x'); 301 } 302 } else 303 gdb_tx_mem(regp, regsz); 304 } 305