1 /****************************************************************************
3 * Realmode X86 Emulator Library
5 * Copyright (C) 1991-2004 SciTech Software, Inc.
6 * Copyright (C) David Mosberger-Tang
7 * Copyright (C) 1999 Egbert Eich
9 * ========================================================================
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.
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.
29 * ========================================================================
33 * Developer: Kendall Bennett
35 * Description: This file contains the code to handle debugging of the
38 ****************************************************************************/
40 #include "x86emu/x86emui.h"
43 /*----------------------------- Implementation ----------------------------*/
47 static void print_encoded_bytes(u16 s, u16 o);
48 static void print_decoded_instruction(void);
49 static int parse_line(char *s, int *ps, int *n);
51 /* should look something like debug's output. */
52 void X86EMU_trace_regs(void)
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();
64 void X86EMU_trace_xregs(void)
71 void x86emu_just_disassemble(void)
74 * This routine called if the flag DEBUG_DISASSEMBLE is set kind
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();
82 static void disassemble_forward(u16 seg, u16 off, int n)
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:
96 * if (debug&DEBUG_DISASSEMBLE)
97 * {just_disassemble(); goto EndOfInstruction;}
98 * if (debug&DEBUG_TRACE) trace_regs(r,m);
100 * ...... and at the last line of the routine.
102 * EndOfInstruction: end_instr();
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
108 * This was done for an entirely different reason, but makes a
109 * nice way to get the system to help debug codes.
112 tregs.x86.R_IP = off;
113 tregs.x86.R_CS = seg;
115 /* reset the decoding buffers */
116 tregs.x86.enc_str_pos = 0;
117 tregs.x86.enc_pos = 0;
119 /* turn on the "disassemble only, no execute" flag */
120 tregs.x86.debug |= DEBUG_DISASSEMBLE_F;
122 /* DUMP NEXT n instructions to screen in straight_line fashion */
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...
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);
134 /* end major hack mode. */
137 void x86emu_check_ip_access(void)
142 void x86emu_check_sp_access(void)
146 void x86emu_check_mem_access(u32 dummy)
148 /* check bounds, etc */
151 void x86emu_check_data_access(uint dummy1, uint dummy2)
153 /* check bounds, etc */
156 void x86emu_inc_decoded_inst_len(int x)
161 void x86emu_decode_printf(char *x)
163 sprintf(M.x86.decoded_buf + M.x86.enc_str_pos, "%s", x);
164 M.x86.enc_str_pos += strlen(x);
167 void x86emu_decode_printf2(char *x, int y)
171 sprintf(M.x86.decoded_buf + M.x86.enc_str_pos, "%s", temp);
172 M.x86.enc_str_pos += strlen(temp);
175 void x86emu_end_instr(void)
177 M.x86.enc_str_pos = 0;
181 static void print_encoded_bytes(u16 s, u16 o)
185 for (i = 0; i < M.x86.enc_pos; i++) {
186 sprintf(buf1 + 2 * i, "%02x", fetch_data_byte_abs(s, o + i));
188 printk("%-20s", buf1);
191 static void print_decoded_instruction(void)
193 printk("%s", M.x86.decoded_buf);
196 void x86emu_print_int_vect(u16 iv)
202 seg = fetch_data_word_abs(0, iv * 4);
203 off = fetch_data_word_abs(0, iv * 4 + 2);
204 printk("%04x:%04x ", seg, off);
207 void X86EMU_dump_memory(u16 seg, u16 off, u32 amt)
209 u32 start = off & 0xfffffff0;
210 u32 end = (off + 16) & 0xfffffff0;
215 while (end <= off + amt) {
216 printk("%04x:%04x ", seg, start);
217 for (i = start; i < off; i++)
220 printk("%02x ", fetch_data_byte_abs(seg, i));
227 void x86emu_single_step(void)
236 static int breakpoint;
237 static int noDecode = 1;
242 if (M.x86.saved_ip != breakpoint) {
245 M.x86.debug &= ~DEBUG_DECODE_NOPRINT_F;
246 M.x86.debug |= DEBUG_TRACE_F;
247 M.x86.debug &= ~DEBUG_BREAK_F;
248 print_decoded_instruction();
253 offset = M.x86.saved_ip;
256 cmd = parse_line(s, ps, &ntok);
259 disassemble_forward(M.x86.saved_cs, (u16) offset, 10);
263 segment = M.x86.saved_cs;
265 X86EMU_dump_memory(segment, (u16) offset, 16);
267 } else if (ntok == 3) {
270 X86EMU_dump_memory(segment, (u16) offset, 16);
273 segment = M.x86.saved_cs;
274 X86EMU_dump_memory(segment, (u16) offset, 16);
279 M.x86.debug ^= DEBUG_TRACECALL_F;
283 DEBUG_SVC_F | DEBUG_SYS_F | DEBUG_SYSINT_F;
289 X86EMU_trace_xregs();
295 M.x86.debug |= DEBUG_DECODE_NOPRINT_F;
297 M.x86.debug &= ~DEBUG_DECODE_NOPRINT_F;
299 M.x86.debug &= ~DEBUG_TRACE_F;
300 M.x86.debug |= DEBUG_BREAK_F;
305 M.x86.debug |= DEBUG_EXIT;
308 noDecode = (noDecode) ? 0 : 1;
309 printk("Toggled decoding to %s\n",
310 (noDecode) ? "FALSE" : "TRUE");
320 int X86EMU_trace_on(void)
322 return M.x86.debug |= DEBUG_STEP_F | DEBUG_DECODE_F | DEBUG_TRACE_F;
325 int X86EMU_trace_off(void)
327 return M.x86.debug &= ~(DEBUG_STEP_F | DEBUG_DECODE_F | DEBUG_TRACE_F);
330 static int parse_line(char *s, int *ps, int *n)
335 while (*s == ' ' || *s == '\t')
348 while (*s != ' ' && *s != '\t' && *s != '\n')
354 while (*s == ' ' || *s == '\t')
363 void x86emu_dump_regs(void)
365 printk("\tAX=%04x ", M.x86.R_AX);
366 printk("BX=%04x ", M.x86.R_BX);
367 printk("CX=%04x ", M.x86.R_CX);
368 printk("DX=%04x ", M.x86.R_DX);
369 printk("SP=%04x ", M.x86.R_SP);
370 printk("BP=%04x ", M.x86.R_BP);
371 printk("SI=%04x ", M.x86.R_SI);
372 printk("DI=%04x\n", M.x86.R_DI);
373 printk("\tDS=%04x ", M.x86.R_DS);
374 printk("ES=%04x ", M.x86.R_ES);
375 printk("SS=%04x ", M.x86.R_SS);
376 printk("CS=%04x ", M.x86.R_CS);
377 printk("IP=%04x ", M.x86.R_IP);
378 if (ACCESS_FLAG(F_OF))
379 printk("OV "); /* CHECKED... */
382 if (ACCESS_FLAG(F_DF))
386 if (ACCESS_FLAG(F_IF))
390 if (ACCESS_FLAG(F_SF))
394 if (ACCESS_FLAG(F_ZF))
398 if (ACCESS_FLAG(F_AF))
402 if (ACCESS_FLAG(F_PF))
406 if (ACCESS_FLAG(F_CF))
413 void x86emu_dump_xregs(void)
415 printk("\tEAX=%08x ", M.x86.R_EAX);
416 printk("EBX=%08x ", M.x86.R_EBX);
417 printk("ECX=%08x ", M.x86.R_ECX);
418 printk("EDX=%08x \n", M.x86.R_EDX);
419 printk("\tESP=%08x ", M.x86.R_ESP);
420 printk("EBP=%08x ", M.x86.R_EBP);
421 printk("ESI=%08x ", M.x86.R_ESI);
422 printk("EDI=%08x\n", M.x86.R_EDI);
423 printk("\tDS=%04x ", M.x86.R_DS);
424 printk("ES=%04x ", M.x86.R_ES);
425 printk("SS=%04x ", M.x86.R_SS);
426 printk("CS=%04x ", M.x86.R_CS);
427 printk("EIP=%08x\n\t", M.x86.R_EIP);
428 if (ACCESS_FLAG(F_OF))
429 printk("OV "); /* CHECKED... */
432 if (ACCESS_FLAG(F_DF))
436 if (ACCESS_FLAG(F_IF))
440 if (ACCESS_FLAG(F_SF))
444 if (ACCESS_FLAG(F_ZF))
448 if (ACCESS_FLAG(F_AF))
452 if (ACCESS_FLAG(F_PF))
456 if (ACCESS_FLAG(F_CF))