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 <linux/ctype.h>
  43#include "x86emu/x86emui.h"
  44
  45/*----------------------------- Implementation ----------------------------*/
  46
  47#ifdef DEBUG
  48
  49static void print_encoded_bytes(u16 s, u16 o);
  50static void print_decoded_instruction(void);
  51static int x86emu_parse_line(char *s, int *ps, int *n);
  52
  53/* should look something like debug's output. */
  54void X86EMU_trace_regs(void)
  55{
  56        if (DEBUG_TRACE()) {
  57                x86emu_dump_regs();
  58        }
  59        if (DEBUG_DECODE() && !DEBUG_DECODE_NOPRINT()) {
  60                printk("%04x:%04x ", M.x86.saved_cs, M.x86.saved_ip);
  61                print_encoded_bytes(M.x86.saved_cs, M.x86.saved_ip);
  62                print_decoded_instruction();
  63        }
  64}
  65
  66void X86EMU_trace_xregs(void)
  67{
  68        if (DEBUG_TRACE()) {
  69                x86emu_dump_xregs();
  70        }
  71}
  72
  73void x86emu_just_disassemble(void)
  74{
  75        /*
  76         * This routine called if the flag DEBUG_DISASSEMBLE is set kind
  77         * of a hack!
  78         */
  79        printk("%04x:%04x ", M.x86.saved_cs, M.x86.saved_ip);
  80        print_encoded_bytes(M.x86.saved_cs, M.x86.saved_ip);
  81        print_decoded_instruction();
  82}
  83
  84static void disassemble_forward(u16 seg, u16 off, int n)
  85{
  86        X86EMU_sysEnv tregs;
  87        int i;
  88        u8 op1;
  89        /*
  90         * hack, hack, hack.  What we do is use the exact machinery set up
  91         * for execution, except that now there is an additional state
  92         * flag associated with the "execution", and we are using a copy
  93         * of the register struct.  All the major opcodes, once fully
  94         * decoded, have the following two steps: TRACE_REGS(r,m);
  95         * SINGLE_STEP(r,m); which disappear if DEBUG is not defined to
  96         * the preprocessor.  The TRACE_REGS macro expands to:
  97         *
  98         * if (debug&DEBUG_DISASSEMBLE)
  99         *     {just_disassemble(); goto EndOfInstruction;}
 100         *     if (debug&DEBUG_TRACE) trace_regs(r,m);
 101         *
 102         * ......  and at the last line of the routine.
 103         *
 104         * EndOfInstruction: end_instr();
 105         *
 106         * Up to the point where TRACE_REG is expanded, NO modifications
 107         * are done to any register EXCEPT the IP register, for fetch and
 108         * decoding purposes.
 109         *
 110         * This was done for an entirely different reason, but makes a
 111         * nice way to get the system to help debug codes.
 112         */
 113        tregs = M;
 114        tregs.x86.R_IP = off;
 115        tregs.x86.R_CS = seg;
 116
 117        /* reset the decoding buffers */
 118        tregs.x86.enc_str_pos = 0;
 119        tregs.x86.enc_pos = 0;
 120
 121        /* turn on the "disassemble only, no execute" flag */
 122        tregs.x86.debug |= DEBUG_DISASSEMBLE_F;
 123
 124        /* DUMP NEXT n instructions to screen in straight_line fashion */
 125        /*
 126         * This looks like the regular instruction fetch stream, except
 127         * that when this occurs, each fetched opcode, upon seeing the
 128         * DEBUG_DISASSEMBLE flag set, exits immediately after decoding
 129         * the instruction.  XXX --- CHECK THAT MEM IS NOT AFFECTED!!!
 130         * Note the use of a copy of the register structure...
 131         */
 132        for (i = 0; i < n; i++) {
 133                op1 = (*sys_rdb) (((u32) M.x86.R_CS << 4) + (M.x86.R_IP++));
 134                (x86emu_optab[op1]) (op1);
 135        }
 136        /* end major hack mode. */
 137}
 138
 139void x86emu_check_ip_access(void)
 140{
 141        /* NULL as of now */
 142}
 143
 144void x86emu_check_sp_access(void)
 145{
 146}
 147
 148void x86emu_check_mem_access(u32 dummy)
 149{
 150        /*  check bounds, etc */
 151}
 152
 153void x86emu_check_data_access(uint dummy1, uint dummy2)
 154{
 155        /*  check bounds, etc */
 156}
 157
 158void x86emu_inc_decoded_inst_len(int x)
 159{
 160        M.x86.enc_pos += x;
 161}
 162
 163void x86emu_decode_printf(char *x)
 164{
 165        sprintf(M.x86.decoded_buf + M.x86.enc_str_pos, "%s", x);
 166        M.x86.enc_str_pos += strlen(x);
 167}
 168
 169void x86emu_decode_printf2(char *x, int y)
 170{
 171        char temp[100];
 172        sprintf(temp, x, y);
 173        sprintf(M.x86.decoded_buf + M.x86.enc_str_pos, "%s", temp);
 174        M.x86.enc_str_pos += strlen(temp);
 175}
 176
 177void x86emu_end_instr(void)
 178{
 179        M.x86.enc_str_pos = 0;
 180        M.x86.enc_pos = 0;
 181}
 182
 183static void print_encoded_bytes(u16 s, u16 o)
 184{
 185        int i;
 186        char buf1[64];
 187        for (i = 0; i < M.x86.enc_pos; i++) {
 188                sprintf(buf1 + 2 * i, "%02x", fetch_data_byte_abs(s, o + i));
 189        }
 190        printk("%-20s", buf1);
 191}
 192
 193static void print_decoded_instruction(void)
 194{
 195        printk("%s", M.x86.decoded_buf);
 196}
 197
 198void x86emu_print_int_vect(u16 iv)
 199{
 200        u16 seg, off;
 201
 202        if (iv > 256)
 203                return;
 204        seg = fetch_data_word_abs(0, iv * 4);
 205        off = fetch_data_word_abs(0, iv * 4 + 2);
 206        printk("%04x:%04x ", seg, off);
 207}
 208
 209void X86EMU_dump_memory(u16 seg, u16 off, u32 amt)
 210{
 211        u32 start = off & 0xfffffff0;
 212        u32 end = (off + 16) & 0xfffffff0;
 213        u32 i;
 214        u32 current;
 215
 216        current = start;
 217        while (end <= off + amt) {
 218                printk("%04x:%04x ", seg, start);
 219                for (i = start; i < off; i++)
 220                        printk("   ");
 221                for (; i < end; i++)
 222                        printk("%02x ", fetch_data_byte_abs(seg, i));
 223                printk("\n");
 224                start = end;
 225                end = start + 16;
 226        }
 227}
 228
 229void x86emu_single_step(void)
 230{
 231        char s[1024];
 232        int ps[10];
 233        int ntok;
 234        int cmd;
 235        int done;
 236        int segment;
 237        int offset;
 238        static int breakpoint;
 239        static int noDecode = 1;
 240
 241        char *p;
 242
 243        if (DEBUG_BREAK()) {
 244                if (M.x86.saved_ip != breakpoint) {
 245                        return;
 246                } else {
 247                        M.x86.debug &= ~DEBUG_DECODE_NOPRINT_F;
 248                        M.x86.debug |= DEBUG_TRACE_F;
 249                        M.x86.debug &= ~DEBUG_BREAK_F;
 250                        print_decoded_instruction();
 251                        X86EMU_trace_regs();
 252                }
 253        }
 254        done = 0;
 255        offset = M.x86.saved_ip;
 256        while (!done) {
 257                printk("-");
 258                cmd = x86emu_parse_line(s, ps, &ntok);
 259                switch (cmd) {
 260                case 'u':
 261                        disassemble_forward(M.x86.saved_cs, (u16) offset, 10);
 262                        break;
 263                case 'd':
 264                        if (ntok == 2) {
 265                                segment = M.x86.saved_cs;
 266                                offset = ps[1];
 267                                X86EMU_dump_memory(segment, (u16) offset, 16);
 268                                offset += 16;
 269                        } else if (ntok == 3) {
 270                                segment = ps[1];
 271                                offset = ps[2];
 272                                X86EMU_dump_memory(segment, (u16) offset, 16);
 273                                offset += 16;
 274                        } else {
 275                                segment = M.x86.saved_cs;
 276                                X86EMU_dump_memory(segment, (u16) offset, 16);
 277                                offset += 16;
 278                        }
 279                        break;
 280                case 'c':
 281                        M.x86.debug ^= DEBUG_TRACECALL_F;
 282                        break;
 283                case 's':
 284                        M.x86.debug ^=
 285                            DEBUG_SVC_F | DEBUG_SYS_F | DEBUG_SYSINT_F;
 286                        break;
 287                case 'r':
 288                        X86EMU_trace_regs();
 289                        break;
 290                case 'x':
 291                        X86EMU_trace_xregs();
 292                        break;
 293                case 'g':
 294                        if (ntok == 2) {
 295                                breakpoint = ps[1];
 296                                if (noDecode) {
 297                                        M.x86.debug |= DEBUG_DECODE_NOPRINT_F;
 298                                } else {
 299                                        M.x86.debug &= ~DEBUG_DECODE_NOPRINT_F;
 300                                }
 301                                M.x86.debug &= ~DEBUG_TRACE_F;
 302                                M.x86.debug |= DEBUG_BREAK_F;
 303                                done = 1;
 304                        }
 305                        break;
 306                case 'q':
 307                        M.x86.debug |= DEBUG_EXIT;
 308                        return;
 309                case 'P':
 310                        noDecode = (noDecode) ? 0 : 1;
 311                        printk("Toggled decoding to %s\n",
 312                               (noDecode) ? "FALSE" : "TRUE");
 313                        break;
 314                case 't':
 315                case 0:
 316                        done = 1;
 317                        break;
 318                }
 319        }
 320}
 321
 322int X86EMU_trace_on(void)
 323{
 324        return M.x86.debug |= DEBUG_STEP_F | DEBUG_DECODE_F | DEBUG_TRACE_F;
 325}
 326
 327int X86EMU_trace_off(void)
 328{
 329        return M.x86.debug &= ~(DEBUG_STEP_F | DEBUG_DECODE_F | DEBUG_TRACE_F);
 330}
 331
 332static int x86emu_parse_line(char *s, int *ps, int *n)
 333{
 334        int cmd;
 335
 336        *n = 0;
 337        while (isblank(*s))
 338                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 (!isblank(*s) && *s != '\n')
 351                        s++;
 352
 353                if (*s == '\n')
 354                        return cmd;
 355
 356                while (isblank(*s))
 357                        s++;
 358
 359                *n += 1;
 360        }
 361}
 362
 363#endif                          /* DEBUG */
 364
 365void x86emu_dump_regs(void)
 366{
 367        printk("\tAX=%04x  ", M.x86.R_AX);
 368        printk("BX=%04x  ", M.x86.R_BX);
 369        printk("CX=%04x  ", M.x86.R_CX);
 370        printk("DX=%04x  ", M.x86.R_DX);
 371        printk("SP=%04x  ", M.x86.R_SP);
 372        printk("BP=%04x  ", M.x86.R_BP);
 373        printk("SI=%04x  ", M.x86.R_SI);
 374        printk("DI=%04x\n", M.x86.R_DI);
 375        printk("\tDS=%04x  ", M.x86.R_DS);
 376        printk("ES=%04x  ", M.x86.R_ES);
 377        printk("SS=%04x  ", M.x86.R_SS);
 378        printk("CS=%04x  ", M.x86.R_CS);
 379        printk("IP=%04x   ", M.x86.R_IP);
 380        if (ACCESS_FLAG(F_OF))
 381                printk("OV ");  /* CHECKED... */
 382        else
 383                printk("NV ");
 384        if (ACCESS_FLAG(F_DF))
 385                printk("DN ");
 386        else
 387                printk("UP ");
 388        if (ACCESS_FLAG(F_IF))
 389                printk("EI ");
 390        else
 391                printk("DI ");
 392        if (ACCESS_FLAG(F_SF))
 393                printk("NG ");
 394        else
 395                printk("PL ");
 396        if (ACCESS_FLAG(F_ZF))
 397                printk("ZR ");
 398        else
 399                printk("NZ ");
 400        if (ACCESS_FLAG(F_AF))
 401                printk("AC ");
 402        else
 403                printk("NA ");
 404        if (ACCESS_FLAG(F_PF))
 405                printk("PE ");
 406        else
 407                printk("PO ");
 408        if (ACCESS_FLAG(F_CF))
 409                printk("CY ");
 410        else
 411                printk("NC ");
 412        printk("\n");
 413}
 414
 415void x86emu_dump_xregs(void)
 416{
 417        printk("\tEAX=%08x  ", M.x86.R_EAX);
 418        printk("EBX=%08x  ", M.x86.R_EBX);
 419        printk("ECX=%08x  ", M.x86.R_ECX);
 420        printk("EDX=%08x  \n", M.x86.R_EDX);
 421        printk("\tESP=%08x  ", M.x86.R_ESP);
 422        printk("EBP=%08x  ", M.x86.R_EBP);
 423        printk("ESI=%08x  ", M.x86.R_ESI);
 424        printk("EDI=%08x\n", M.x86.R_EDI);
 425        printk("\tDS=%04x  ", M.x86.R_DS);
 426        printk("ES=%04x  ", M.x86.R_ES);
 427        printk("SS=%04x  ", M.x86.R_SS);
 428        printk("CS=%04x  ", M.x86.R_CS);
 429        printk("EIP=%08x\n\t", M.x86.R_EIP);
 430        if (ACCESS_FLAG(F_OF))
 431                printk("OV ");  /* CHECKED... */
 432        else
 433                printk("NV ");
 434        if (ACCESS_FLAG(F_DF))
 435                printk("DN ");
 436        else
 437                printk("UP ");
 438        if (ACCESS_FLAG(F_IF))
 439                printk("EI ");
 440        else
 441                printk("DI ");
 442        if (ACCESS_FLAG(F_SF))
 443                printk("NG ");
 444        else
 445                printk("PL ");
 446        if (ACCESS_FLAG(F_ZF))
 447                printk("ZR ");
 448        else
 449                printk("NZ ");
 450        if (ACCESS_FLAG(F_AF))
 451                printk("AC ");
 452        else
 453                printk("NA ");
 454        if (ACCESS_FLAG(F_PF))
 455                printk("PE ");
 456        else
 457                printk("PO ");
 458        if (ACCESS_FLAG(F_CF))
 459                printk("CY ");
 460        else
 461                printk("NC ");
 462        printk("\n");
 463}
 464