LXR coreboot-v2/util/vgabios/x86emu/src/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 "x86emu/x86emui.h"
  41#include <stdarg.h>
  42
  43/*----------------------------- Implementation ----------------------------*/
  44
  45#ifdef DEBUG
  46
  47static void     print_encoded_bytes (u16 s, u16 o);
  48static void     print_decoded_instruction (void);
  49static int      parse_line (char *s, int *ps, int *n);
  50
  51/* should look something like debug's output. */
  52void X86EMU_trace_regs (void)
  53{
  54    if (DEBUG_TRACE()) {
  55        x86emu_dump_regs();
  56    }
  57    if (DEBUG_DECODE() && ! DEBUG_DECODE_NOPRINT()) {
  58        printk("%04x:%04x ",M.x86.saved_cs, M.x86.saved_ip);
  59        print_encoded_bytes( M.x86.saved_cs, M.x86.saved_ip);
  60        print_decoded_instruction();
  61    }
  62}
  63
  64void X86EMU_trace_xregs (void)
  65{
  66    if (DEBUG_TRACE()) {
  67        x86emu_dump_xregs();
  68    }
  69}
  70
  71void x86emu_just_disassemble (void)
  72{
  73    /*
  74     * This routine called if the flag DEBUG_DISASSEMBLE is set kind
  75     * of a hack!
  76     */
  77    printk("%04x:%04x ",M.x86.saved_cs, M.x86.saved_ip);
  78    print_encoded_bytes( M.x86.saved_cs, M.x86.saved_ip);
  79    print_decoded_instruction();
  80}
  81
  82static void disassemble_forward (u16 seg, u16 off, int n)
  83{
  84    X86EMU_sysEnv tregs;
  85    int i;
  86    u8 op1;
  87    /*
  88     * hack, hack, hack.  What we do is use the exact machinery set up
  89     * for execution, except that now there is an additional state
  90     * flag associated with the "execution", and we are using a copy
  91     * of the register struct.  All the major opcodes, once fully
  92     * decoded, have the following two steps: TRACE_REGS(r,m);
  93     * SINGLE_STEP(r,m); which disappear if DEBUG is not defined to
  94     * the preprocessor.  The TRACE_REGS macro expands to:
  95     *
  96     * if (debug&DEBUG_DISASSEMBLE)
  97     *     {just_disassemble(); goto EndOfInstruction;}
  98     *     if (debug&DEBUG_TRACE) trace_regs(r,m);
  99     *
 100     * ......  and at the last line of the routine.
 101     *
 102     * EndOfInstruction: end_instr();
 103     *
 104     * Up to the point where TRACE_REG is expanded, NO modifications
 105     * are done to any register EXCEPT the IP register, for fetch and
 106     * decoding purposes.
 107     *
 108     * This was done for an entirely different reason, but makes a
 109     * nice way to get the system to help debug codes.
 110     */
 111    tregs = M;
 112    tregs.x86.R_IP = off;
 113    tregs.x86.R_CS = seg;
 114
 115    /* reset the decoding buffers */
 116    tregs.x86.enc_str_pos = 0;
 117    tregs.x86.enc_pos = 0;
 118
 119    /* turn on the "disassemble only, no execute" flag */
 120    tregs.x86.debug |= DEBUG_DISASSEMBLE_F;
 121
 122    /* DUMP NEXT n instructions to screen in straight_line fashion */
 123    /*
 124     * This looks like the regular instruction fetch stream, except
 125     * that when this occurs, each fetched opcode, upon seeing the
 126     * DEBUG_DISASSEMBLE flag set, exits immediately after decoding
 127     * the instruction.  XXX --- CHECK THAT MEM IS NOT AFFECTED!!!
 128     * Note the use of a copy of the register structure...
 129     */
 130    for (i=0; i<n; i++) {
 131        op1 = (*sys_rdb)(((u32)M.x86.R_CS<<4) + (M.x86.R_IP++));
 132        (x86emu_optab[op1])(op1);
 133    }
 134    /* end major hack mode. */
 135}
 136
 137void x86emu_check_ip_access (void)
 138{
 139    /* NULL as of now */
 140}
 141
 142void x86emu_check_sp_access (void)
 143{
 144}
 145
 146void x86emu_check_mem_access (u32 dummy)
 147{
 148    /*  check bounds, etc */
 149}
 150
 151void x86emu_check_data_access (uint dummy1, uint dummy2)
 152{
 153    /*  check bounds, etc */
 154}
 155
 156void x86emu_inc_decoded_inst_len (int x)
 157{
 158    M.x86.enc_pos += x;
 159}
 160
 161void x86emu_decode_printf (char *x)
 162{
 163    sprintf(M.x86.decoded_buf+M.x86.enc_str_pos,"%s",x);
 164    M.x86.enc_str_pos += strlen(x);
 165}
 166
 167void x86emu_decode_printf2 (char *x, int y)
 168{
 169    char temp[100];
 170    sprintf(temp,x,y);
 171    sprintf(M.x86.decoded_buf+M.x86.enc_str_pos,"%s",temp);
 172    M.x86.enc_str_pos += strlen(temp);
 173}
 174
 175void x86emu_end_instr (void)
 176{
 177    M.x86.enc_str_pos = 0;
 178    M.x86.enc_pos = 0;
 179}
 180
 181static void print_encoded_bytes (u16 s, u16 o)
 182{
 183    int i;
 184    char buf1[64];
 185    for (i=0; i< M.x86.enc_pos; i++) {
 186        sprintf(buf1+2*i,"%02x", fetch_data_byte_abs(s,o+i));
 187    }
 188    printk("%-20s",buf1);
 189}
 190
 191static void print_decoded_instruction (void)
 192{
 193    printk("%s", M.x86.decoded_buf);
 194}
 195
 196void x86emu_print_int_vect (u16 iv)
 197{
 198    u16 seg,off;
 199
 200    if (iv > 256) return;
 201    seg   = fetch_data_word_abs(0,iv*4);
 202    off   = fetch_data_word_abs(0,iv*4+2);
 203    printk("%04x:%04x ", seg, off);
 204}
 205
 206void X86EMU_dump_memory (u16 seg, u16 off, u32 amt)
 207{
 208    u32 start = off & 0xfffffff0;
 209    u32 end  = (off+16) & 0xfffffff0;
 210    u32 i;
 211    u32 current;
 212
 213    current = start;
 214    while (end <= off + amt) {
 215        printk("%04x:%04x ", seg, start);
 216        for (i=start; i< off; i++)
 217          printk("   ");
 218        for (       ; i< end; i++)
 219          printk("%02x ", fetch_data_byte_abs(seg,i));
 220        printk("\n");
 221        start = end;
 222        end = start + 16;
 223    }
 224}
 225
 226void x86emu_single_step (void)
 227{
 228    char s[1024];
 229    int ps[10];
 230    int ntok;
 231    int cmd;
 232    int done;
 233        int segment;
 234    int offset;
 235    static int breakpoint;
 236    static int noDecode = 1;
 237
 238    char *p;
 239
 240        if (DEBUG_BREAK()) {
 241                if (M.x86.saved_ip != breakpoint) {
 242                        return;
 243                } else {
 244              M.x86.debug &= ~DEBUG_DECODE_NOPRINT_F;
 245                        M.x86.debug |= DEBUG_TRACE_F;
 246                        M.x86.debug &= ~DEBUG_BREAK_F;
 247                        print_decoded_instruction ();
 248                        X86EMU_trace_regs();
 249                }
 250        }
 251    done=0;
 252    offset = M.x86.saved_ip;
 253    while (!done) {
 254        printk("-");
 255        p = fgets(s, 1023, stdin);
 256        cmd = parse_line(s, ps, &ntok);
 257        switch(cmd) {
 258          case 'u':
 259            disassemble_forward(M.x86.saved_cs,(u16)offset,10);
 260            break;
 261          case 'd':
 262                            if (ntok == 2) {
 263                                    segment = M.x86.saved_cs;
 264                                    offset = ps[1];
 265                                    X86EMU_dump_memory(segment,(u16)offset,16);
 266                                    offset += 16;
 267                            } else if (ntok == 3) {
 268                                    segment = ps[1];
 269                                    offset = ps[2];
 270                                    X86EMU_dump_memory(segment,(u16)offset,16);
 271                                    offset += 16;
 272                            } else {
 273                                    segment = M.x86.saved_cs;
 274                                    X86EMU_dump_memory(segment,(u16)offset,16);
 275                                    offset += 16;
 276                            }
 277            break;
 278          case 'c':
 279            M.x86.debug ^= DEBUG_TRACECALL_F;
 280            break;
 281          case 's':
 282            M.x86.debug ^= DEBUG_SVC_F | DEBUG_SYS_F | DEBUG_SYSINT_F;
 283            break;
 284          case 'r':
 285            X86EMU_trace_regs();
 286            break;
 287          case 'x':
 288            X86EMU_trace_xregs();
 289            break;
 290          case 'g':
 291            if (ntok == 2) {
 292                breakpoint = ps[1];
 293        if (noDecode) {
 294                        M.x86.debug |= DEBUG_DECODE_NOPRINT_F;
 295        } else {
 296                        M.x86.debug &= ~DEBUG_DECODE_NOPRINT_F;
 297        }
 298        M.x86.debug &= ~DEBUG_TRACE_F;
 299        M.x86.debug |= DEBUG_BREAK_F;
 300        done = 1;
 301            }
 302            break;
 303          case 'q':
 304          M.x86.debug |= DEBUG_EXIT;
 305          return;
 306      case 'P':
 307          noDecode = (noDecode)?0:1;
 308          printk("Toggled decoding to %s\n",(noDecode)?"FALSE":"TRUE");
 309          break;
 310          case 't':
 311      case 0:
 312            done = 1;
 313            break;
 314        }
 315    }
 316}
 317
 318int X86EMU_trace_on(void)
 319{
 320    return M.x86.debug |= DEBUG_STEP_F | DEBUG_DECODE_F | DEBUG_TRACE_F;
 321}
 322
 323int X86EMU_trace_off(void)
 324{
 325    return M.x86.debug &= ~(DEBUG_STEP_F | DEBUG_DECODE_F | DEBUG_TRACE_F);
 326}
 327
 328static int parse_line (char *s, int *ps, int *n)
 329{
 330    int cmd;
 331
 332    *n = 0;
 333    while(*s == ' ' || *s == '\t') s++;
 334    ps[*n] = *s;
 335    switch (*s) {
 336      case '\n':
 337        *n += 1;
 338        return 0;
 339      default:
 340        cmd = *s;
 341        *n += 1;
 342    }
 343
 344    while (1) {
 345        while (*s != ' ' && *s != '\t' && *s != '\n')  s++;
 346
 347        if (*s == '\n')
 348            return cmd;
 349
 350        while(*s == ' ' || *s == '\t') s++;
 351
 352        sscanf(s,"%x",&ps[*n]);
 353        *n += 1;
 354    }
 355}
 356
 357#endif /* DEBUG */
 358
 359void x86emu_dump_regs (void)
 360{
 361    printk("\tAX=%04x  ", M.x86.R_AX );
 362    printk("BX=%04x  ", M.x86.R_BX );
 363    printk("CX=%04x  ", M.x86.R_CX );
 364    printk("DX=%04x  ", M.x86.R_DX );
 365    printk("SP=%04x  ", M.x86.R_SP );
 366    printk("BP=%04x  ", M.x86.R_BP );
 367    printk("SI=%04x  ", M.x86.R_SI );
 368    printk("DI=%04x\n", M.x86.R_DI );
 369    printk("\tDS=%04x  ", M.x86.R_DS );
 370    printk("ES=%04x  ", M.x86.R_ES );
 371    printk("SS=%04x  ", M.x86.R_SS );
 372    printk("CS=%04x  ", M.x86.R_CS );
 373    printk("IP=%04x   ", M.x86.R_IP );
 374    if (ACCESS_FLAG(F_OF))    printk("OV ");     /* CHECKED... */
 375    else                        printk("NV ");
 376    if (ACCESS_FLAG(F_DF))    printk("DN ");
 377    else                        printk("UP ");
 378    if (ACCESS_FLAG(F_IF))    printk("EI ");
 379    else                        printk("DI ");
 380    if (ACCESS_FLAG(F_SF))    printk("NG ");
 381    else                        printk("PL ");
 382    if (ACCESS_FLAG(F_ZF))    printk("ZR ");
 383    else                        printk("NZ ");
 384    if (ACCESS_FLAG(F_AF))    printk("AC ");
 385    else                        printk("NA ");
 386    if (ACCESS_FLAG(F_PF))    printk("PE ");
 387    else                        printk("PO ");
 388    if (ACCESS_FLAG(F_CF))    printk("CY ");
 389    else                        printk("NC ");
 390    printk("\n");
 391}
 392
 393void x86emu_dump_xregs (void)
 394{
 395    printk("\tEAX=%08x  ", M.x86.R_EAX );
 396    printk("EBX=%08x  ", M.x86.R_EBX );
 397    printk("ECX=%08x  ", M.x86.R_ECX );
 398    printk("EDX=%08x  \n", M.x86.R_EDX );
 399    printk("\tESP=%08x  ", M.x86.R_ESP );
 400    printk("EBP=%08x  ", M.x86.R_EBP );
 401    printk("ESI=%08x  ", M.x86.R_ESI );
 402    printk("EDI=%08x\n", M.x86.R_EDI );
 403    printk("\tDS=%04x  ", M.x86.R_DS );
 404    printk("ES=%04x  ", M.x86.R_ES );
 405    printk("SS=%04x  ", M.x86.R_SS );
 406    printk("CS=%04x  ", M.x86.R_CS );
 407    printk("EIP=%08x\n\t", M.x86.R_EIP );
 408    if (ACCESS_FLAG(F_OF))    printk("OV ");     /* CHECKED... */
 409    else                        printk("NV ");
 410    if (ACCESS_FLAG(F_DF))    printk("DN ");
 411    else                        printk("UP ");
 412    if (ACCESS_FLAG(F_IF))    printk("EI ");
 413    else                        printk("DI ");
 414    if (ACCESS_FLAG(F_SF))    printk("NG ");
 415    else                        printk("PL ");
 416    if (ACCESS_FLAG(F_ZF))    printk("ZR ");
 417    else                        printk("NZ ");
 418    if (ACCESS_FLAG(F_AF))    printk("AC ");
 419    else                        printk("NA ");
 420    if (ACCESS_FLAG(F_PF))    printk("PE ");
 421    else                        printk("PO ");
 422    if (ACCESS_FLAG(F_CF))    printk("CY ");
 423    else                        printk("NC ");
 424    printk("\n");
 425}
 426