| /**************************************************************************** |
| * |
| * Realmode X86 Emulator Library |
| * |
| * Copyright (C) 1991-2004 SciTech Software, Inc. |
| * Copyright (C) David Mosberger-Tang |
| * Copyright (C) 1999 Egbert Eich |
| * |
| * ======================================================================== |
| * |
| * Permission to use, copy, modify, distribute, and sell this software and |
| * its documentation for any purpose is hereby granted without fee, |
| * provided that the above copyright notice appear in all copies and that |
| * both that copyright notice and this permission notice appear in |
| * supporting documentation, and that the name of the authors not be used |
| * in advertising or publicity pertaining to distribution of the software |
| * without specific, written prior permission. The authors makes no |
| * representations about the suitability of this software for any purpose. |
| * It is provided "as is" without express or implied warranty. |
| * |
| * THE AUTHORS DISCLAIMS ALL WARRANTIES WITH REGARD TO THIS SOFTWARE, |
| * INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS, IN NO |
| * EVENT SHALL THE AUTHORS BE LIABLE FOR ANY SPECIAL, INDIRECT OR |
| * CONSEQUENTIAL DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM LOSS OF |
| * USE, DATA OR PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE OR |
| * OTHER TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR |
| * PERFORMANCE OF THIS SOFTWARE. |
| * |
| * ======================================================================== |
| * |
| * Language: ANSI C |
| * Environment: Any |
| * Developer: Kendall Bennett |
| * |
| * Description: This file contains the code to handle debugging of the |
| * emulator. |
| * |
| ****************************************************************************/ |
| |
| #include "x86emui.h" |
| |
| /*----------------------------- Implementation ----------------------------*/ |
| |
| #ifdef DEBUG |
| |
| static void print_encoded_bytes (u16 s, u16 o); |
| static void print_decoded_instruction (void); |
| int parse_line (char *s, int *ps, int *n); |
| |
| /* should look something like debug's output. */ |
| void X86EMU_trace_regs (void) |
| { |
| if (DEBUG_TRACE()) { |
| if (M.x86.mode & (SYSMODE_PREFIX_DATA | SYSMODE_PREFIX_ADDR)) { |
| x86emu_dump_xregs(); |
| } else { |
| x86emu_dump_regs(); |
| } |
| } |
| if (DEBUG_DECODE() && ! DEBUG_DECODE_NOPRINT()) { |
| printf("%04x:%04x ",M.x86.saved_cs, M.x86.saved_ip); |
| print_encoded_bytes( M.x86.saved_cs, M.x86.saved_ip); |
| print_decoded_instruction(); |
| } |
| } |
| |
| void X86EMU_trace_xregs (void) |
| { |
| if (DEBUG_TRACE()) { |
| x86emu_dump_xregs(); |
| } |
| } |
| |
| void x86emu_just_disassemble (void) |
| { |
| /* |
| * This routine called if the flag DEBUG_DISASSEMBLE is set kind |
| * of a hack! |
| */ |
| printf("%04x:%04x ",M.x86.saved_cs, M.x86.saved_ip); |
| print_encoded_bytes( M.x86.saved_cs, M.x86.saved_ip); |
| print_decoded_instruction(); |
| } |
| |
| void disassemble_forward (u16 seg, u16 off, int n) |
| { |
| X86EMU_sysEnv tregs; |
| int i; |
| u8 op1; |
| /* |
| * hack, hack, hack. What we do is use the exact machinery set up |
| * for execution, except that now there is an additional state |
| * flag associated with the "execution", and we are using a copy |
| * of the register struct. All the major opcodes, once fully |
| * decoded, have the following two steps: TRACE_REGS(r,m); |
| * SINGLE_STEP(r,m); which disappear if DEBUG is not defined to |
| * the preprocessor. The TRACE_REGS macro expands to: |
| * |
| * if (debug&DEBUG_DISASSEMBLE) |
| * {just_disassemble(); goto EndOfInstruction;} |
| * if (debug&DEBUG_TRACE) trace_regs(r,m); |
| * |
| * ...... and at the last line of the routine. |
| * |
| * EndOfInstruction: end_instr(); |
| * |
| * Up to the point where TRACE_REG is expanded, NO modifications |
| * are done to any register EXCEPT the IP register, for fetch and |
| * decoding purposes. |
| * |
| * This was done for an entirely different reason, but makes a |
| * nice way to get the system to help debug codes. |
| */ |
| tregs = M; |
| tregs.x86.R_IP = off; |
| tregs.x86.R_CS = seg; |
| |
| /* reset the decoding buffers */ |
| tregs.x86.enc_str_pos = 0; |
| tregs.x86.enc_pos = 0; |
| |
| /* turn on the "disassemble only, no execute" flag */ |
| tregs.x86.debug |= DEBUG_DISASSEMBLE_F; |
| |
| /* DUMP NEXT n instructions to screen in straight_line fashion */ |
| /* |
| * This looks like the regular instruction fetch stream, except |
| * that when this occurs, each fetched opcode, upon seeing the |
| * DEBUG_DISASSEMBLE flag set, exits immediately after decoding |
| * the instruction. XXX --- CHECK THAT MEM IS NOT AFFECTED!!! |
| * Note the use of a copy of the register structure... |
| */ |
| for (i=0; i<n; i++) { |
| op1 = (*sys_rdb)(((u32)M.x86.R_CS<<4) + (M.x86.R_IP++)); |
| (x86emu_optab[op1])(op1); |
| } |
| /* end major hack mode. */ |
| } |
| |
| void x86emu_check_ip_access (void) |
| { |
| /* NULL as of now */ |
| } |
| |
| void x86emu_check_sp_access (void) |
| { |
| } |
| |
| void x86emu_check_mem_access (u32 dummy) |
| { |
| /* check bounds, etc */ |
| } |
| |
| void x86emu_check_data_access (uint dummy1, uint dummy2) |
| { |
| /* check bounds, etc */ |
| } |
| |
| void x86emu_inc_decoded_inst_len (int x) |
| { |
| M.x86.enc_pos += x; |
| } |
| |
| void x86emu_decode_printf (const char *x) |
| { |
| strcpy(M.x86.decoded_buf+M.x86.enc_str_pos,x); |
| M.x86.enc_str_pos += strlen(x); |
| } |
| |
| void x86emu_decode_printf2 (const char *x, int y) |
| { |
| char temp[100]; |
| snprintf(temp, sizeof (temp), x,y); |
| strcpy(M.x86.decoded_buf+M.x86.enc_str_pos,temp); |
| M.x86.enc_str_pos += strlen(temp); |
| } |
| |
| void x86emu_end_instr (void) |
| { |
| M.x86.enc_str_pos = 0; |
| M.x86.enc_pos = 0; |
| } |
| |
| static void print_encoded_bytes (u16 s, u16 o) |
| { |
| int i; |
| char buf1[64]; |
| for (i=0; i< M.x86.enc_pos; i++) { |
| snprintf(buf1+2*i, 64 - 2 * i, "%02x", fetch_data_byte_abs(s,o+i)); |
| } |
| printf("%-20s ",buf1); |
| } |
| |
| static void print_decoded_instruction (void) |
| { |
| printf("%s", M.x86.decoded_buf); |
| } |
| |
| void x86emu_print_int_vect (u16 iv) |
| { |
| u16 seg,off; |
| |
| if (iv > 256) return; |
| seg = fetch_data_word_abs(0,iv*4); |
| off = fetch_data_word_abs(0,iv*4+2); |
| printf("%04x:%04x ", seg, off); |
| } |
| |
| void X86EMU_dump_memory (u16 seg, u16 off, u32 amt) |
| { |
| u32 start = off & 0xfffffff0; |
| u32 end = (off+16) & 0xfffffff0; |
| u32 i; |
| |
| while (end <= off + amt) { |
| printf("%04x:%04x ", seg, start); |
| for (i=start; i< off; i++) |
| printf(" "); |
| for ( ; i< end; i++) |
| printf("%02x ", fetch_data_byte_abs(seg,i)); |
| printf("\n"); |
| start = end; |
| end = start + 16; |
| } |
| } |
| |
| void x86emu_single_step (void) |
| { |
| #if 0 |
| char s[1024]; |
| int ps[10]; |
| int ntok; |
| int cmd; |
| int done; |
| int segment; |
| int offset; |
| static int breakpoint; |
| static int noDecode = 1; |
| |
| if (DEBUG_BREAK()) { |
| if (M.x86.saved_ip != breakpoint) { |
| return; |
| } else { |
| M.x86.debug &= ~DEBUG_DECODE_NOPRINT_F; |
| M.x86.debug |= DEBUG_TRACE_F; |
| M.x86.debug &= ~DEBUG_BREAK_F; |
| print_decoded_instruction (); |
| X86EMU_trace_regs(); |
| } |
| } |
| done=0; |
| offset = M.x86.saved_ip; |
| while (!done) { |
| printf("-"); |
| (void)fgets(s, 1023, stdin); |
| cmd = parse_line(s, ps, &ntok); |
| switch(cmd) { |
| case 'u': |
| disassemble_forward(M.x86.saved_cs,(u16)offset,10); |
| break; |
| case 'd': |
| if (ntok == 2) { |
| segment = M.x86.saved_cs; |
| offset = ps[1]; |
| X86EMU_dump_memory(segment,(u16)offset,16); |
| offset += 16; |
| } else if (ntok == 3) { |
| segment = ps[1]; |
| offset = ps[2]; |
| X86EMU_dump_memory(segment,(u16)offset,16); |
| offset += 16; |
| } else { |
| segment = M.x86.saved_cs; |
| X86EMU_dump_memory(segment,(u16)offset,16); |
| offset += 16; |
| } |
| break; |
| case 'c': |
| M.x86.debug ^= DEBUG_TRACECALL_F; |
| break; |
| case 's': |
| M.x86.debug ^= DEBUG_SVC_F | DEBUG_SYS_F | DEBUG_SYSINT_F; |
| break; |
| case 'r': |
| X86EMU_trace_regs(); |
| break; |
| case 'x': |
| X86EMU_trace_xregs(); |
| break; |
| case 'g': |
| if (ntok == 2) { |
| breakpoint = ps[1]; |
| if (noDecode) { |
| M.x86.debug |= DEBUG_DECODE_NOPRINT_F; |
| } else { |
| M.x86.debug &= ~DEBUG_DECODE_NOPRINT_F; |
| } |
| M.x86.debug &= ~DEBUG_TRACE_F; |
| M.x86.debug |= DEBUG_BREAK_F; |
| done = 1; |
| } |
| break; |
| case 'q': |
| M.x86.debug |= DEBUG_EXIT; |
| return; |
| case 'P': |
| noDecode = (noDecode)?0:1; |
| printf("Toggled decoding to %s\n",(noDecode)?"FALSE":"TRUE"); |
| break; |
| case 't': |
| case 0: |
| done = 1; |
| break; |
| } |
| } |
| #endif |
| } |
| |
| int X86EMU_trace_on(void) |
| { |
| return M.x86.debug |= DEBUG_STEP_F | DEBUG_DECODE_F | DEBUG_TRACE_F; |
| } |
| |
| int X86EMU_trace_off(void) |
| { |
| return M.x86.debug &= ~(DEBUG_STEP_F | DEBUG_DECODE_F | DEBUG_TRACE_F); |
| } |
| |
| int parse_line (char *s, int *ps, int *n) |
| { |
| #if 0 |
| int cmd; |
| |
| *n = 0; |
| while(*s == ' ' || *s == '\t') s++; |
| ps[*n] = *s; |
| switch (*s) { |
| case '\n': |
| *n += 1; |
| return 0; |
| default: |
| cmd = *s; |
| *n += 1; |
| } |
| |
| while (1) { |
| while (*s != ' ' && *s != '\t' && *s != '\n') s++; |
| |
| if (*s == '\n') |
| return cmd; |
| |
| while(*s == ' ' || *s == '\t') s++; |
| |
| sscanf(s,"%x",&ps[*n]); |
| *n += 1; |
| } |
| #else |
| return 0; |
| #endif |
| } |
| |
| #endif /* DEBUG */ |
| |
| void x86emu_dump_regs (void) |
| { |
| printf("\tAX=%04x ", M.x86.R_AX ); |
| printf("BX=%04x ", M.x86.R_BX ); |
| printf("CX=%04x ", M.x86.R_CX ); |
| printf("DX=%04x ", M.x86.R_DX ); |
| printf("SP=%04x ", M.x86.R_SP ); |
| printf("BP=%04x ", M.x86.R_BP ); |
| printf("SI=%04x ", M.x86.R_SI ); |
| printf("DI=%04x\n", M.x86.R_DI ); |
| printf("\tDS=%04x ", M.x86.R_DS ); |
| printf("ES=%04x ", M.x86.R_ES ); |
| printf("SS=%04x ", M.x86.R_SS ); |
| printf("CS=%04x ", M.x86.R_CS ); |
| printf("IP=%04x ", M.x86.R_IP ); |
| if (ACCESS_FLAG(F_OF)) printf("OV "); /* CHECKED... */ |
| else printf("NV "); |
| if (ACCESS_FLAG(F_DF)) printf("DN "); |
| else printf("UP "); |
| if (ACCESS_FLAG(F_IF)) printf("EI "); |
| else printf("DI "); |
| if (ACCESS_FLAG(F_SF)) printf("NG "); |
| else printf("PL "); |
| if (ACCESS_FLAG(F_ZF)) printf("ZR "); |
| else printf("NZ "); |
| if (ACCESS_FLAG(F_AF)) printf("AC "); |
| else printf("NA "); |
| if (ACCESS_FLAG(F_PF)) printf("PE "); |
| else printf("PO "); |
| if (ACCESS_FLAG(F_CF)) printf("CY "); |
| else printf("NC "); |
| printf("\n"); |
| } |
| |
| void x86emu_dump_xregs (void) |
| { |
| printf("\tEAX=%08x ", M.x86.R_EAX ); |
| printf("EBX=%08x ", M.x86.R_EBX ); |
| printf("ECX=%08x ", M.x86.R_ECX ); |
| printf("EDX=%08x \n", M.x86.R_EDX ); |
| printf("\tESP=%08x ", M.x86.R_ESP ); |
| printf("EBP=%08x ", M.x86.R_EBP ); |
| printf("ESI=%08x ", M.x86.R_ESI ); |
| printf("EDI=%08x\n", M.x86.R_EDI ); |
| printf("\tDS=%04x ", M.x86.R_DS ); |
| printf("ES=%04x ", M.x86.R_ES ); |
| printf("SS=%04x ", M.x86.R_SS ); |
| printf("CS=%04x ", M.x86.R_CS ); |
| printf("EIP=%08x\n\t", M.x86.R_EIP ); |
| if (ACCESS_FLAG(F_OF)) printf("OV "); /* CHECKED... */ |
| else printf("NV "); |
| if (ACCESS_FLAG(F_DF)) printf("DN "); |
| else printf("UP "); |
| if (ACCESS_FLAG(F_IF)) printf("EI "); |
| else printf("DI "); |
| if (ACCESS_FLAG(F_SF)) printf("NG "); |
| else printf("PL "); |
| if (ACCESS_FLAG(F_ZF)) printf("ZR "); |
| else printf("NZ "); |
| if (ACCESS_FLAG(F_AF)) printf("AC "); |
| else printf("NA "); |
| if (ACCESS_FLAG(F_PF)) printf("PE "); |
| else printf("PO "); |
| if (ACCESS_FLAG(F_CF)) printf("CY "); |
| else printf("NC "); |
| printf("\n"); |
| } |