LXR uboot/drivers/bios_emulator/x86emu/debug.c

   1/****************************************************************************
   2*
   3*                       Realmode X86 Emulator Library
   4*
   5*               Copyright (C) 1991-2004 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 <stdarg.h>
  41#include <common.h>
  42#include "x86emu/x86emui.h"
  43
  44/*----------------------------- Implementation ----------------------------*/
  45
  46#ifdef DEBUG
  47
  48static void print_encoded_bytes(u16 s, u16 o);
  49static void print_decoded_instruction(void);
  50static int x86emu_parse_line(char *s, int *ps, int *n);
  51
  52/* should look something like debug's output. */
  53void X86EMU_trace_regs(void)
  54{
  55        if (DEBUG_TRACE()) {
  56                x86emu_dump_regs();
  57        }
  58        if (DEBUG_DECODE() && !DEBUG_DECODE_NOPRINT()) {
  59                printk("%04x:%04x ", M.x86.saved_cs, M.x86.saved_ip);
  60                print_encoded_bytes(M.x86.saved_cs, M.x86.saved_ip);
  61                print_decoded_instruction();
  62        }
  63}
  64
  65void X86EMU_trace_xregs(void)
  66{
  67        if (DEBUG_TRACE()) {
  68                x86emu_dump_xregs();
  69        }
  70}
  71
  72void x86emu_just_disassemble(void)
  73{
  74        /*
  75         * This routine called if the flag DEBUG_DISASSEMBLE is set kind
  76         * of a hack!
  77         */
  78        printk("%04x:%04x ", M.x86.saved_cs, M.x86.saved_ip);
  79        print_encoded_bytes(M.x86.saved_cs, M.x86.saved_ip);
  80        print_decoded_instruction();
  81}
  82
  83static void disassemble_forward(u16 seg, u16 off, int n)
  84{
  85        X86EMU_sysEnv tregs;
  86        int i;
  87        u8 op1;
  88        /*
  89         * hack, hack, hack.  What we do is use the exact machinery set up
  90         * for execution, except that now there is an additional state
  91         * flag associated with the "execution", and we are using a copy
  92         * of the register struct.  All the major opcodes, once fully
  93         * decoded, have the following two steps: TRACE_REGS(r,m);
  94         * SINGLE_STEP(r,m); which disappear if DEBUG is not defined to
  95         * the preprocessor.  The TRACE_REGS macro expands to:
  96         *
  97         * if (debug&DEBUG_DISASSEMBLE)
  98         *     {just_disassemble(); goto EndOfInstruction;}
  99         *     if (debug&DEBUG_TRACE) trace_regs(r,m);
 100         *
 101         * ......  and at the last line of the routine.
 102         *
 103         * EndOfInstruction: end_instr();
 104         *
 105         * Up to the point where TRACE_REG is expanded, NO modifications
 106         * are done to any register EXCEPT the IP register, for fetch and
 107         * decoding purposes.
 108         *
 109         * This was done for an entirely different reason, but makes a
 110         * nice way to get the system to help debug codes.
 111         */
 112        tregs = M;
 113        tregs.x86.R_IP = off;
 114        tregs.x86.R_CS = seg;
 115
 116        /* reset the decoding buffers */
 117        tregs.x86.enc_str_pos = 0;
 118        tregs.x86.enc_pos = 0;
 119
 120        /* turn on the "disassemble only, no execute" flag */
 121        tregs.x86.debug |= DEBUG_DISASSEMBLE_F;
 122
 123        /* DUMP NEXT n instructions to screen in straight_line fashion */
 124        /*
 125         * This looks like the regular instruction fetch stream, except
 126         * that when this occurs, each fetched opcode, upon seeing the
 127         * DEBUG_DISASSEMBLE flag set, exits immediately after decoding
 128         * the instruction.  XXX --- CHECK THAT MEM IS NOT AFFECTED!!!
 129         * Note the use of a copy of the register structure...
 130         */
 131        for (i = 0; i < n; i++) {
 132                op1 = (*sys_rdb) (((u32) M.x86.R_CS << 4) + (M.x86.R_IP++));
 133                (x86emu_optab[op1]) (op1);
 134        }
 135        /* end major hack mode. */
 136}
 137
 138void x86emu_check_ip_access(void)
 139{
 140        /* NULL as of now */
 141}
 142
 143void x86emu_check_sp_access(void)
 144{
 145}
 146
 147void x86emu_check_mem_access(u32 dummy)
 148{
 149        /*  check bounds, etc */
 150}
 151
 152void x86emu_check_data_access(uint dummy1, uint dummy2)
 153{
 154        /*  check bounds, etc */
 155}
 156
 157void x86emu_inc_decoded_inst_len(int x)
 158{
 159        M.x86.enc_pos += x;
 160}
 161
 162void x86emu_decode_printf(char *x)
 163{
 164        sprintf(M.x86.decoded_buf + M.x86.enc_str_pos, "%s", x);
 165        M.x86.enc_str_pos += strlen(x);
 166}
 167
 168void x86emu_decode_printf2(char *x, int y)
 169{
 170        char temp[100];
 171        sprintf(temp, x, y);
 172        sprintf(M.x86.decoded_buf + M.x86.enc_str_pos, "%s", temp);
 173        M.x86.enc_str_pos += strlen(temp);
 174}
 175
 176void x86emu_end_instr(void)
 177{
 178        M.x86.enc_str_pos = 0;
 179        M.x86.enc_pos = 0;
 180}
 181
 182static void print_encoded_bytes(u16 s, u16 o)
 183{
 184        int i;
 185        char buf1[64];
 186        for (i = 0; i < M.x86.enc_pos; i++) {
 187                sprintf(buf1 + 2 * i, "%02x", fetch_data_byte_abs(s, o + i));
 188        }
 189        printk("%-20s", buf1);
 190}
 191
 192static void print_decoded_instruction(void)
 193{
 194        printk("%s", M.x86.decoded_buf);
 195}
 196
 197void x86emu_print_int_vect(u16 iv)
 198{
 199        u16 seg, off;
 200
 201        if (iv > 256)
 202                return;
 203        seg = fetch_data_word_abs(0, iv * 4);
 204        off = fetch_data_word_abs(0, iv * 4 + 2);
 205        printk("%04x:%04x ", seg, off);
 206}
 207
 208void X86EMU_dump_memory(u16 seg, u16 off, u32 amt)
 209{
 210        u32 start = off & 0xfffffff0;
 211        u32 end = (off + 16) & 0xfffffff0;
 212        u32 i;
 213        u32 current;
 214
 215        current = start;
 216        while (end <= off + amt) {
 217                printk("%04x:%04x ", seg, start);
 218                for (i = start; i < off; i++)
 219                        printk("   ");
 220                for (; i < end; i++)
 221                        printk("%02x ", fetch_data_byte_abs(seg, i));
 222                printk("\n");
 223                start = end;
 224                end = start + 16;
 225        }
 226}
 227
 228void x86emu_single_step(void)
 229{
 230        char s[1024];
 231        int ps[10];
 232        int ntok;
 233        int cmd;
 234        int done;
 235        int segment;
 236        int offset;
 237        static int breakpoint;
 238        static int noDecode = 1;
 239
 240        char *p;
 241
 242        if (DEBUG_BREAK()) {
 243                if (M.x86.saved_ip != breakpoint) {
 244                        return;
 245                } else {
 246                        M.x86.debug &= ~DEBUG_DECODE_NOPRINT_F;
 247                        M.x86.debug |= DEBUG_TRACE_F;
 248                        M.x86.debug &= ~DEBUG_BREAK_F;
 249                        print_decoded_instruction();
 250                        X86EMU_trace_regs();
 251                }
 252        }
 253        done = 0;
 254        offset = M.x86.saved_ip;
 255        while (!done) {
 256                printk("-");
 257                cmd = x86emu_parse_line(s, ps, &ntok);
 258                switch (cmd) {
 259                case 'u':
 260                        disassemble_forward(M.x86.saved_cs, (u16) offset, 10);
 261                        break;
 262                case 'd':
 263                        if (ntok == 2) {
 264                                segment = M.x86.saved_cs;
 265                                offset = ps[1];
 266                                X86EMU_dump_memory(segment, (u16) offset, 16);
 267                                offset += 16;
 268                        } else if (ntok == 3) {
 269                                segment = ps[1];
 270                                offset = ps[2];
 271                                X86EMU_dump_memory(segment, (u16) offset, 16);
 272                                offset += 16;
 273                        } else {
 274                                segment = M.x86.saved_cs;
 275                                X86EMU_dump_memory(segment, (u16) offset, 16);
 276                                offset += 16;
 277                        }
 278                        break;
 279                case 'c':
 280                        M.x86.debug ^= DEBUG_TRACECALL_F;
 281                        break;
 282                case 's':
 283                        M.x86.debug ^=
 284                            DEBUG_SVC_F | DEBUG_SYS_F | DEBUG_SYSINT_F;
 285                        break;
 286                case 'r':
 287                        X86EMU_trace_regs();
 288                        break;
 289                case 'x':
 290                        X86EMU_trace_xregs();
 291                        break;
 292                case 'g':
 293                        if (ntok == 2) {
 294                                breakpoint = ps[1];
 295                                if (noDecode) {
 296                                        M.x86.debug |= DEBUG_DECODE_NOPRINT_F;
 297                                } else {
 298                                        M.x86.debug &= ~DEBUG_DECODE_NOPRINT_F;
 299                                }
 300                                M.x86.debug &= ~DEBUG_TRACE_F;
 301                                M.x86.debug |= DEBUG_BREAK_F;
 302                                done = 1;
 303                        }
 304                        break;
 305                case 'q':
 306                        M.x86.debug |= DEBUG_EXIT;
 307                        return;
 308                case 'P':
 309                        noDecode = (noDecode) ? 0 : 1;
 310                        printk("Toggled decoding to %s\n",
 311                               (noDecode) ? "FALSE" : "TRUE");
 312                        break;
 313                case 't':
 314                case 0:
 315                        done = 1;
 316                        break;
 317                }
 318        }
 319}
 320
 321int X86EMU_trace_on(void)
 322{
 323        return M.x86.debug |= DEBUG_STEP_F | DEBUG_DECODE_F | DEBUG_TRACE_F;
 324}
 325
 326int X86EMU_trace_off(void)
 327{
 328        return M.x86.debug &= ~(DEBUG_STEP_F | DEBUG_DECODE_F | DEBUG_TRACE_F);
 329}
 330
 331static int x86emu_parse_line(char *s, int *ps, int *n)
 332{
 333        int cmd;
 334
 335        *n = 0;
 336        while (*s == ' ' || *s == '\t')
 337                s++;
 338        ps[*n] = *s;
 339        switch (*s) {
 340        case '\n':
 341                *n += 1;
 342                return 0;
 343        default:
 344                cmd = *s;
 345                *n += 1;
 346        }
 347
 348        while (1) {
 349                while (*s != ' ' && *s != '\t' && *s != '\n')
 350                        s++;
 351
 352                if (*s == '\n')
 353                        return cmd;
 354
 355                while (*s == ' ' || *s == '\t')
 356                        s++;
 357
 358                *n += 1;
 359        }
 360}
 361
 362#endif                          /* DEBUG */
 363
 364void 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))
 380                printk("OV ");  /* CHECKED... */
 381        else
 382                printk("NV ");
 383        if (ACCESS_FLAG(F_DF))
 384                printk("DN ");
 385        else
 386                printk("UP ");
 387        if (ACCESS_FLAG(F_IF))
 388                printk("EI ");
 389        else
 390                printk("DI ");
 391        if (ACCESS_FLAG(F_SF))
 392                printk("NG ");
 393        else
 394                printk("PL ");
 395        if (ACCESS_FLAG(F_ZF))
 396                printk("ZR ");
 397        else
 398                printk("NZ ");
 399        if (ACCESS_FLAG(F_AF))
 400                printk("AC ");
 401        else
 402                printk("NA ");
 403        if (ACCESS_FLAG(F_PF))
 404                printk("PE ");
 405        else
 406                printk("PO ");
 407        if (ACCESS_FLAG(F_CF))
 408                printk("CY ");
 409        else
 410                printk("NC ");
 411        printk("\n");
 412}
 413
 414void x86emu_dump_xregs(void)
 415{
 416        printk("\tEAX=%08x  ", M.x86.R_EAX);
 417        printk("EBX=%08x  ", M.x86.R_EBX);
 418        printk("ECX=%08x  ", M.x86.R_ECX);
 419        printk("EDX=%08x  \n", M.x86.R_EDX);
 420        printk("\tESP=%08x  ", M.x86.R_ESP);
 421        printk("EBP=%08x  ", M.x86.R_EBP);
 422        printk("ESI=%08x  ", M.x86.R_ESI);
 423        printk("EDI=%08x\n", M.x86.R_EDI);
 424        printk("\tDS=%04x  ", M.x86.R_DS);
 425        printk("ES=%04x  ", M.x86.R_ES);
 426        printk("SS=%04x  ", M.x86.R_SS);
 427        printk("CS=%04x  ", M.x86.R_CS);
 428        printk("EIP=%08x\n\t", M.x86.R_EIP);
 429        if (ACCESS_FLAG(F_OF))
 430                printk("OV ");  /* CHECKED... */
 431        else
 432                printk("NV ");
 433        if (ACCESS_FLAG(F_DF))
 434                printk("DN ");
 435        else
 436                printk("UP ");
 437        if (ACCESS_FLAG(F_IF))
 438                printk("EI ");
 439        else
 440                printk("DI ");
 441        if (ACCESS_FLAG(F_SF))
 442                printk("NG ");
 443        else
 444                printk("PL ");
 445        if (ACCESS_FLAG(F_ZF))
 446                printk("ZR ");
 447        else
 448                printk("NZ ");
 449        if (ACCESS_FLAG(F_AF))
 450                printk("AC ");
 451        else
 452                printk("NA ");
 453        if (ACCESS_FLAG(F_PF))
 454                printk("PE ");
 455        else
 456                printk("PO ");
 457        if (ACCESS_FLAG(F_CF))
 458                printk("CY ");
 459        else
 460                printk("NC ");
 461        printk("\n");
 462}
 463