xorg-server-1.4/hw/xfree86/x86emu/debug.c

   1 /****************************************************************************
   2 *
   3 *                                               Realmode X86 Emulator Library
   4 *
   5 *               Copyright (C) 1996-1999 SciTech Software, Inc.
   6 *                                    Copyright (C) David Mosberger-Tang
   7 *                                          Copyright (C) 1999 Egbert Eich
   8 *
   9 *  ========================================================================
  10 *
  11 *  Permission to use, copy, modify, distribute, and sell this software and
  12 *  its documentation for any purpose is hereby granted without fee,
  13 *  provided that the above copyright notice appear in all copies and that
  14 *  both that copyright notice and this permission notice appear in
  15 *  supporting documentation, and that the name of the authors not be used
  16 *  in advertising or publicity pertaining to distribution of the software
  17 *  without specific, written prior permission.  The authors makes no
  18 *  representations about the suitability of this software for any purpose.
  19 *  It is provided "as is" without express or implied warranty.
  20 *
  21 *  THE AUTHORS DISCLAIMS ALL WARRANTIES WITH REGARD TO THIS SOFTWARE,
  22 *  INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS, IN NO
  23 *  EVENT SHALL THE AUTHORS BE LIABLE FOR ANY SPECIAL, INDIRECT OR
  24 *  CONSEQUENTIAL DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM LOSS OF
  25 *  USE, DATA OR PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE OR
  26 *  OTHER TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR
  27 *  PERFORMANCE OF THIS SOFTWARE.
  28 *
  29 *  ========================================================================
  30 *
  31 * Language:             ANSI C
  32 * Environment:  Any
  33 * Developer:    Kendall Bennett
  34 *
  35 * Description:  This file contains the code to handle debugging of the
  36 *                               emulator.
  37 *
  38 ****************************************************************************/
  39
  40 #include "x86emu/x86emui.h"
  41 #include <stdio.h>
  42 #include <string.h>
  43 #ifndef NO_SYS_HEADERS
  44 #include <stdarg.h>
  45 #include <stdlib.h>
  46 #endif
  47
  48 /*----------------------------- Implementation ----------------------------*/
  49
  50 #ifdef DEBUG
  51
  52 static void     print_encoded_bytes (u16 s, u16 o);
  53 static void     print_decoded_instruction (void);
  54 static int      parse_line (char *s, int *ps, int *n);
  55
  56 /* should look something like debug's output. */
  57 void X86EMU_trace_regs (void)
  58 {
  59         if (DEBUG_TRACE()) {
  60                 x86emu_dump_regs();
  61     }
  62         if (DEBUG_DECODE() && ! DEBUG_DECODE_NOPRINT()) {
  63                 printk("%04x:%04x ",M.x86.saved_cs, M.x86.saved_ip);
  64                 print_encoded_bytes( M.x86.saved_cs, M.x86.saved_ip);
  65                 print_decoded_instruction();
  66     }
  67 }
  68
  69 void X86EMU_trace_xregs (void)
  70 {
  71         if (DEBUG_TRACE()) {
  72                 x86emu_dump_xregs();
  73     }
  74 }
  75
  76 void x86emu_just_disassemble (void)
  77 {
  78     /*
  79      * This routine called if the flag DEBUG_DISASSEMBLE is set kind
  80      * of a hack!
  81      */
  82         printk("%04x:%04x ",M.x86.saved_cs, M.x86.saved_ip);
  83         print_encoded_bytes( M.x86.saved_cs, M.x86.saved_ip);
  84         print_decoded_instruction();
  85 }
  86
  87 static void disassemble_forward (u16 seg, u16 off, int n)
  88 {
  89         X86EMU_sysEnv tregs;
  90         int i;
  91         u8 op1;
  92     /*
  93      * hack, hack, hack.  What we do is use the exact machinery set up
  94      * for execution, except that now there is an additional state
  95      * flag associated with the "execution", and we are using a copy
  96      * of the register struct.  All the major opcodes, once fully
  97      * decoded, have the following two steps: TRACE_REGS(r,m);
  98      * SINGLE_STEP(r,m); which disappear if DEBUG is not defined to
  99      * the preprocessor.  The TRACE_REGS macro expands to:
 100      *
 101      * if (debug&DEBUG_DISASSEMBLE)
 102      *     {just_disassemble(); goto EndOfInstruction;}
 103      *     if (debug&DEBUG_TRACE) trace_regs(r,m);
 104      *
 105      * ......  and at the last line of the routine.
 106      *
 107      * EndOfInstruction: end_instr();
 108      *
 109      * Up to the point where TRACE_REG is expanded, NO modifications
 110      * are done to any register EXCEPT the IP register, for fetch and
 111      * decoding purposes.
 112      *
 113      * This was done for an entirely different reason, but makes a
 114      * nice way to get the system to help debug codes.
 115      */
 116         tregs = M;
 117     tregs.x86.R_IP = off;
 118     tregs.x86.R_CS = seg;
 119
 120     /* reset the decoding buffers */
 121     tregs.x86.enc_str_pos = 0;
 122     tregs.x86.enc_pos = 0;
 123
 124     /* turn on the "disassemble only, no execute" flag */
 125     tregs.x86.debug |= DEBUG_DISASSEMBLE_F;
 126
 127     /* DUMP NEXT n instructions to screen in straight_line fashion */
 128     /*
 129      * This looks like the regular instruction fetch stream, except
 130      * that when this occurs, each fetched opcode, upon seeing the
 131      * DEBUG_DISASSEMBLE flag set, exits immediately after decoding
 132      * the instruction.  XXX --- CHECK THAT MEM IS NOT AFFECTED!!!
 133      * Note the use of a copy of the register structure...
 134      */
 135     for (i=0; i<n; i++) {
 136                 op1 = (*sys_rdb)(((u32)M.x86.R_CS<<4) + (M.x86.R_IP++));
 137                 (x86emu_optab[op1])(op1);
 138     }
 139     /* end major hack mode. */
 140 }
 141
 142 void x86emu_check_ip_access (void)
 143 {
 144     /* NULL as of now */
 145 }
 146
 147 void x86emu_check_sp_access (void)
 148 {
 149 }
 150
 151 void x86emu_check_mem_access (u32 dummy)
 152 {
 153         /*  check bounds, etc */
 154 }
 155
 156 void x86emu_check_data_access (uint dummy1, uint dummy2)
 157 {
 158         /*  check bounds, etc */
 159 }
 160
 161 void x86emu_inc_decoded_inst_len (int x)
 162 {
 163         M.x86.enc_pos += x;
 164 }
 165
 166 void x86emu_decode_printf (char *x)
 167 {
 168         sprintf(M.x86.decoded_buf+M.x86.enc_str_pos,"%s",x);
 169         M.x86.enc_str_pos += strlen(x);
 170 }
 171
 172 void x86emu_decode_printf2 (char *x, int y)
 173 {
 174         char temp[100];
 175         sprintf(temp,x,y);
 176         sprintf(M.x86.decoded_buf+M.x86.enc_str_pos,"%s",temp);
 177         M.x86.enc_str_pos += strlen(temp);
 178 }
 179
 180 void x86emu_end_instr (void)
 181 {
 182         M.x86.enc_str_pos = 0;
 183         M.x86.enc_pos = 0;
 184 }
 185
 186 static void print_encoded_bytes (u16 s, u16 o)
 187 {
 188     int i;
 189     char buf1[64];
 190         for (i=0; i< M.x86.enc_pos; i++) {
 191                 sprintf(buf1+2*i,"%02x", fetch_data_byte_abs(s,o+i));
 192     }
 193         printk("%-20s",buf1);
 194 }
 195
 196 static void print_decoded_instruction (void)
 197 {
 198         printk("%s", M.x86.decoded_buf);
 199 }
 200
 201 void x86emu_print_int_vect (u16 iv)
 202 {
 203         u16 seg,off;
 204
 205         if (iv > 256) return;
 206         seg   = fetch_data_word_abs(0,iv*4);
 207         off   = fetch_data_word_abs(0,iv*4+2);
 208         printk("%04x:%04x ", seg, off);
 209 }
 210
 211 void X86EMU_dump_memory (u16 seg, u16 off, u32 amt)
 212 {
 213         u32 start = off & 0xfffffff0;
 214         u32 end  = (off+16) & 0xfffffff0;
 215         u32 i;
 216         u32 current;
 217
 218         current = start;
 219         while (end <= off + amt) {
 220                 printk("%04x:%04x ", seg, start);
 221                 for (i=start; i< off; i++)
 222                   printk("   ");
 223                 for (       ; i< end; i++)
 224                   printk("%02x ", fetch_data_byte_abs(seg,i));
 225                 printk("\n");
 226                 start = end;
 227                 end = start + 16;
 228         }
 229 }
 230
 231 void x86emu_single_step (void)
 232 {
 233     char s[1024];
 234     int ps[10];
 235     int ntok;
 236     int cmd;
 237     int done;
 238                 int segment;
 239     int offset;
 240     static int breakpoint;
 241     static int noDecode = 1;
 242
 243     char *p;
 244
 245                 if (DEBUG_BREAK()) {
 246                                 if (M.x86.saved_ip != breakpoint) {
 247                                                 return;
 248                                 } else {
 249                   M.x86.debug &= ~DEBUG_DECODE_NOPRINT_F;
 250                                                 M.x86.debug |= DEBUG_TRACE_F;
 251                                                 M.x86.debug &= ~DEBUG_BREAK_F;
 252                                                 print_decoded_instruction ();
 253                                                 X86EMU_trace_regs();
 254                                 }
 255                 }
 256     done=0;
 257         offset = M.x86.saved_ip;
 258     while (!done) {
 259         printk("-");
 260         p = fgets(s, 1023, stdin);
 261         cmd = parse_line(s, ps, &ntok);
 262         switch(cmd) {
 263           case 'u':
 264                         disassemble_forward(M.x86.saved_cs,(u16)offset,10);
 265             break;
 266           case 'd':
 267                                                         if (ntok == 2) {
 268                                                                         segment = M.x86.saved_cs;
 269                                                                         offset = ps[1];
 270                                                                         X86EMU_dump_memory(segment,(u16)offset,16);
 271                                                                         offset += 16;
 272                                                         } else if (ntok == 3) {
 273                                                                         segment = ps[1];
 274                                                                         offset = ps[2];
 275                                                                         X86EMU_dump_memory(segment,(u16)offset,16);
 276                                                                         offset += 16;
 277                                                         } else {
 278                                                                         segment = M.x86.saved_cs;
 279                                                                         X86EMU_dump_memory(segment,(u16)offset,16);
 280                                                                         offset += 16;
 281                                                         }
 282             break;
 283           case 'c':
 284                         M.x86.debug ^= DEBUG_TRACECALL_F;
 285             break;
 286           case 's':
 287                         M.x86.debug ^= DEBUG_SVC_F | DEBUG_SYS_F | DEBUG_SYSINT_F;
 288             break;
 289           case 'r':
 290                         X86EMU_trace_regs();
 291             break;
 292           case 'x':
 293                         X86EMU_trace_xregs();
 294             break;
 295           case 'g':
 296             if (ntok == 2) {
 297                 breakpoint = ps[1];
 298                 if (noDecode) {
 299                                 M.x86.debug |= DEBUG_DECODE_NOPRINT_F;
 300                 } else {
 301                                 M.x86.debug &= ~DEBUG_DECODE_NOPRINT_F;
 302                 }
 303                 M.x86.debug &= ~DEBUG_TRACE_F;
 304                 M.x86.debug |= DEBUG_BREAK_F;
 305                 done = 1;
 306             }
 307             break;
 308           case 'q':
 309           M.x86.debug |= DEBUG_EXIT;
 310           return;
 311           case 'P':
 312               noDecode = (noDecode)?0:1;
 313               printk("Toggled decoding to %s\n",(noDecode)?"FALSE":"TRUE");
 314               break;
 315           case 't':
 316           case 0:
 317             done = 1;
 318             break;
 319         }
 320     }
 321 }
 322
 323 int X86EMU_trace_on(void)
 324 {
 325         return M.x86.debug |= DEBUG_STEP_F | DEBUG_DECODE_F | DEBUG_TRACE_F;
 326 }
 327
 328 int X86EMU_trace_off(void)
 329 {
 330         return M.x86.debug &= ~(DEBUG_STEP_F | DEBUG_DECODE_F | DEBUG_TRACE_F);
 331 }
 332
 333 static int parse_line (char *s, int *ps, int *n)
 334 {
 335     int cmd;
 336
 337     *n = 0;
 338     while(*s == ' ' || *s == '\t') s++;
 339     ps[*n] = *s;
 340     switch (*s) {
 341       case '\n':
 342         *n += 1;
 343         return 0;
 344       default:
 345         cmd = *s;
 346         *n += 1;
 347     }
 348
 349         while (1) {
 350                 while (*s != ' ' && *s != '\t' && *s != '\n')  s++;
 351
 352                 if (*s == '\n')
 353                         return cmd;
 354
 355                 while(*s == ' ' || *s == '\t') s++;
 356
 357                 sscanf(s,"%x",&ps[*n]);
 358                 *n += 1;
 359         }
 360 }
 361
 362 #endif /* DEBUG */
 363
 364 void x86emu_dump_regs (void)
 365 {
 366         printk("\tAX=%04x  ", M.x86.R_AX );
 367         printk("BX=%04x  ", M.x86.R_BX );
 368         printk("CX=%04x  ", M.x86.R_CX );
 369         printk("DX=%04x  ", M.x86.R_DX );
 370         printk("SP=%04x  ", M.x86.R_SP );
 371         printk("BP=%04x  ", M.x86.R_BP );
 372         printk("SI=%04x  ", M.x86.R_SI );
 373         printk("DI=%04x\n", M.x86.R_DI );
 374         printk("\tDS=%04x  ", M.x86.R_DS );
 375         printk("ES=%04x  ", M.x86.R_ES );
 376         printk("SS=%04x  ", M.x86.R_SS );
 377         printk("CS=%04x  ", M.x86.R_CS );
 378         printk("IP=%04x   ", M.x86.R_IP );
 379         if (ACCESS_FLAG(F_OF))    printk("OV ");     /* CHECKED... */
 380         else                        printk("NV ");
 381         if (ACCESS_FLAG(F_DF))    printk("DN ");
 382         else                        printk("UP ");
 383         if (ACCESS_FLAG(F_IF))    printk("EI ");
 384         else                        printk("DI ");
 385         if (ACCESS_FLAG(F_SF))    printk("NG ");
 386         else                        printk("PL ");
 387         if (ACCESS_FLAG(F_ZF))    printk("ZR ");
 388         else                        printk("NZ ");
 389         if (ACCESS_FLAG(F_AF))    printk("AC ");
 390         else                        printk("NA ");
 391         if (ACCESS_FLAG(F_PF))    printk("PE ");
 392         else                        printk("PO ");
 393         if (ACCESS_FLAG(F_CF))    printk("CY ");
 394         else                        printk("NC ");
 395         printk("\n");
 396 }
 397
 398 void x86emu_dump_xregs (void)
 399 {
 400         printk("\tEAX=%08x  ", M.x86.R_EAX );
 401         printk("EBX=%08x  ", M.x86.R_EBX );
 402         printk("ECX=%08x  ", M.x86.R_ECX );
 403         printk("EDX=%08x  \n", M.x86.R_EDX );
 404         printk("\tESP=%08x  ", M.x86.R_ESP );
 405         printk("EBP=%08x  ", M.x86.R_EBP );
 406         printk("ESI=%08x  ", M.x86.R_ESI );
 407         printk("EDI=%08x\n", M.x86.R_EDI );
 408         printk("\tDS=%04x  ", M.x86.R_DS );
 409         printk("ES=%04x  ", M.x86.R_ES );
 410         printk("SS=%04x  ", M.x86.R_SS );
 411         printk("CS=%04x  ", M.x86.R_CS );
 412         printk("EIP=%08x\n\t", M.x86.R_EIP );
 413         if (ACCESS_FLAG(F_OF))    printk("OV ");     /* CHECKED... */
 414         else                        printk("NV ");
 415         if (ACCESS_FLAG(F_DF))    printk("DN ");
 416         else                        printk("UP ");
 417         if (ACCESS_FLAG(F_IF))    printk("EI ");
 418         else                        printk("DI ");
 419         if (ACCESS_FLAG(F_SF))    printk("NG ");
 420         else                        printk("PL ");
 421         if (ACCESS_FLAG(F_ZF))    printk("ZR ");
 422         else                        printk("NZ ");
 423         if (ACCESS_FLAG(F_AF))    printk("AC ");
 424         else                        printk("NA ");
 425         if (ACCESS_FLAG(F_PF))    printk("PE ");
 426         else                        printk("PO ");
 427         if (ACCESS_FLAG(F_CF))    printk("CY ");
 428         else                        printk("NC ");
 429         printk("\n");
 430 }