1/****************************************************************************
2*
3*						Realmode X86 Emulator Library
4*
5*            	Copyright (C) 1996-1999 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 <stdio.h>
42#include <string.h>
43#ifndef NO_SYS_HEADERS
44#include <stdarg.h>
45#include <stdlib.h>
46#endif
47
48/*----------------------------- Implementation ----------------------------*/
49
50#ifdef DEBUG
51
52static void print_encoded_bytes(u16 s, u16 o);
53static void print_decoded_instruction(void);
54static int parse_line(char *s, int *ps, int *n);
55
56/* should look something like debug's output. */
57void
58X86EMU_trace_regs(void)
59{
60    if (DEBUG_TRACE()) {
61        x86emu_dump_regs();
62    }
63    if (DEBUG_DECODE() && !DEBUG_DECODE_NOPRINT()) {
64        printk("%04x:%04x ", M.x86.saved_cs, M.x86.saved_ip);
65        print_encoded_bytes(M.x86.saved_cs, M.x86.saved_ip);
66        print_decoded_instruction();
67    }
68}
69
70void
71X86EMU_trace_xregs(void)
72{
73    if (DEBUG_TRACE()) {
74        x86emu_dump_xregs();
75    }
76}
77
78void
79x86emu_just_disassemble(void)
80{
81    /*
82     * This routine called if the flag DEBUG_DISASSEMBLE is set kind
83     * of a hack!
84     */
85    printk("%04x:%04x ", M.x86.saved_cs, M.x86.saved_ip);
86    print_encoded_bytes(M.x86.saved_cs, M.x86.saved_ip);
87    print_decoded_instruction();
88}
89
90static void
91disassemble_forward(u16 seg, u16 off, int n)
92{
93    X86EMU_sysEnv tregs;
94    int i;
95    u8 op1;
96
97    /*
98     * hack, hack, hack.  What we do is use the exact machinery set up
99     * for execution, except that now there is an additional state
100     * flag associated with the "execution", and we are using a copy
101     * of the register struct.  All the major opcodes, once fully
102     * decoded, have the following two steps: TRACE_REGS(r,m);
103     * SINGLE_STEP(r,m); which disappear if DEBUG is not defined to
104     * the preprocessor.  The TRACE_REGS macro expands to:
105     *
106     * if (debug&DEBUG_DISASSEMBLE)
107     *     {just_disassemble(); goto EndOfInstruction;}
108     *     if (debug&DEBUG_TRACE) trace_regs(r,m);
109     *
110     * ......  and at the last line of the routine.
111     *
112     * EndOfInstruction: end_instr();
113     *
114     * Up to the point where TRACE_REG is expanded, NO modifications
115     * are done to any register EXCEPT the IP register, for fetch and
116     * decoding purposes.
117     *
118     * This was done for an entirely different reason, but makes a
119     * nice way to get the system to help debug codes.
120     */
121    tregs = M;
122    tregs.x86.R_IP = off;
123    tregs.x86.R_CS = seg;
124
125    /* reset the decoding buffers */
126    tregs.x86.enc_str_pos = 0;
127    tregs.x86.enc_pos = 0;
128
129    /* turn on the "disassemble only, no execute" flag */
130    tregs.x86.debug |= DEBUG_DISASSEMBLE_F;
131
132    /* DUMP NEXT n instructions to screen in straight_line fashion */
133    /*
134     * This looks like the regular instruction fetch stream, except
135     * that when this occurs, each fetched opcode, upon seeing the
136     * DEBUG_DISASSEMBLE flag set, exits immediately after decoding
137     * the instruction.  XXX --- CHECK THAT MEM IS NOT AFFECTED!!!
138     * Note the use of a copy of the register structure...
139     */
140    for (i = 0; i < n; i++) {
141        op1 = (*sys_rdb) (((u32) M.x86.R_CS << 4) + (M.x86.R_IP++));
142        (x86emu_optab[op1]) (op1);
143    }
144    /* end major hack mode. */
145}
146
147void
148x86emu_check_ip_access(void)
149{
150    /* NULL as of now */
151}
152
153void
154x86emu_check_sp_access(void)
155{
156}
157
158void
159x86emu_check_mem_access(u32 dummy)
160{
161    /*  check bounds, etc */
162}
163
164void
165x86emu_check_data_access(uint dummy1, uint dummy2)
166{
167    /*  check bounds, etc */
168}
169
170void
171x86emu_inc_decoded_inst_len(int x)
172{
173    M.x86.enc_pos += x;
174}
175
176void
177x86emu_decode_printf(const char *x)
178{
179    sprintf(M.x86.decoded_buf + M.x86.enc_str_pos, "%s", x);
180    M.x86.enc_str_pos += strlen(x);
181}
182
183void
184x86emu_decode_printf2(const char *x, int y)
185{
186    char temp[100];
187
188    snprintf(temp, sizeof(temp), x, y);
189    sprintf(M.x86.decoded_buf + M.x86.enc_str_pos, "%s", temp);
190    M.x86.enc_str_pos += strlen(temp);
191}
192
193void
194x86emu_end_instr(void)
195{
196    M.x86.enc_str_pos = 0;
197    M.x86.enc_pos = 0;
198}
199
200static void
201print_encoded_bytes(u16 s, u16 o)
202{
203    int i;
204    char buf1[64];
205
206    for (i = 0; i < M.x86.enc_pos; i++) {
207        sprintf(buf1 + 2 * i, "%02x", fetch_data_byte_abs(s, o + i));
208    }
209    printk("%-20s", buf1);
210}
211
212static void
213print_decoded_instruction(void)
214{
215    printk("%s", M.x86.decoded_buf);
216}
217
218void
219x86emu_print_int_vect(u16 iv)
220{
221    u16 seg, off;
222
223    if (iv > 256)
224        return;
225    seg = fetch_data_word_abs(0, iv * 4);
226    off = fetch_data_word_abs(0, iv * 4 + 2);
227    printk("%04x:%04x ", seg, off);
228}
229
230void
231X86EMU_dump_memory(u16 seg, u16 off, u32 amt)
232{
233    u32 start = off & 0xfffffff0;
234    u32 end = (off + 16) & 0xfffffff0;
235    u32 i;
236    u32 current;
237
238    current = start;
239    while (end <= off + amt) {
240        printk("%04x:%04x ", seg, start);
241        for (i = start; i < off; i++)
242            printk("   ");
243        for (; i < end; i++)
244            printk("%02x ", fetch_data_byte_abs(seg, i));
245        printk("\n");
246        start = end;
247        end = start + 16;
248    }
249}
250
251void
252x86emu_single_step(void)
253{
254	return;
255    char s[1024];
256    int ps[10];
257    int ntok;
258    int cmd;
259    int done;
260    int segment;
261    int offset;
262    static int breakpoint;
263    static int noDecode = 1;
264
265    //char *p;
266
267    if (DEBUG_BREAK()) {
268        if (M.x86.saved_ip != breakpoint) {
269            return;
270        }
271        else {
272            M.x86.debug &= ~DEBUG_DECODE_NOPRINT_F;
273            M.x86.debug |= DEBUG_TRACE_F;
274            M.x86.debug &= ~DEBUG_BREAK_F;
275            print_decoded_instruction();
276            X86EMU_trace_regs();
277        }
278    }
279    done = 0;
280    offset = M.x86.saved_ip;
281    while (!done) {
282        printk("-");
283        //p = fgets(s, 1023, stdin);
284        cmd = parse_line(s, ps, &ntok);
285        switch (cmd) {
286        case 'u':
287            disassemble_forward(M.x86.saved_cs, (u16) offset, 10);
288            break;
289        case 'd':
290            if (ntok == 2) {
291                segment = M.x86.saved_cs;
292                offset = ps[1];
293                X86EMU_dump_memory(segment, (u16) offset, 16);
294                offset += 16;
295            }
296            else if (ntok == 3) {
297                segment = ps[1];
298                offset = ps[2];
299                X86EMU_dump_memory(segment, (u16) offset, 16);
300                offset += 16;
301            }
302            else {
303                segment = M.x86.saved_cs;
304                X86EMU_dump_memory(segment, (u16) offset, 16);
305                offset += 16;
306            }
307            break;
308        case 'c':
309            M.x86.debug ^= DEBUG_TRACECALL_F;
310            break;
311        case 's':
312            M.x86.debug ^= DEBUG_SVC_F | DEBUG_SYS_F | DEBUG_SYSINT_F;
313            break;
314        case 'r':
315            X86EMU_trace_regs();
316            break;
317        case 'x':
318            X86EMU_trace_xregs();
319            break;
320        case 'g':
321            if (ntok == 2) {
322                breakpoint = ps[1];
323                if (noDecode) {
324                    M.x86.debug |= DEBUG_DECODE_NOPRINT_F;
325                }
326                else {
327                    M.x86.debug &= ~DEBUG_DECODE_NOPRINT_F;
328                }
329                M.x86.debug &= ~DEBUG_TRACE_F;
330                M.x86.debug |= DEBUG_BREAK_F;
331                done = 1;
332            }
333            break;
334        case 'q':
335            M.x86.debug |= DEBUG_EXIT;
336            return;
337        case 'P':
338            noDecode = (noDecode) ? 0 : 1;
339            printk("Toggled decoding to %s\n", (noDecode) ? "FALSE" : "TRUE");
340            break;
341        case 't':
342        case 0:
343            done = 1;
344            break;
345        }
346    }
347}
348
349int
350X86EMU_trace_on(void)
351{
352    return M.x86.debug |= DEBUG_STEP_F | DEBUG_DECODE_F | DEBUG_TRACE_F;
353}
354
355int
356X86EMU_trace_off(void)
357{
358    return M.x86.debug &= ~(DEBUG_STEP_F | DEBUG_DECODE_F | DEBUG_TRACE_F);
359}
360
361static int
362parse_line(char *s, int *ps, int *n)
363{
364    int cmd;
365
366    *n = 0;
367    while (*s == ' ' || *s == '\t')
368        s++;
369    ps[*n] = *s;
370    switch (*s) {
371    case '\n':
372        *n += 1;
373        return 0;
374    default:
375        cmd = *s;
376        *n += 1;
377    }
378
379    while (1) {
380        while (*s != ' ' && *s != '\t' && *s != '\n')
381            s++;
382
383        if (*s == '\n')
384            return cmd;
385
386        while (*s == ' ' || *s == '\t')
387            s++;
388
389        //sscanf(s, "%x", &ps[*n]);
390        *n += 1;
391    }
392}
393
394#endif                          /* DEBUG */
395
396void
397x86emu_dump_regs(void)
398{
399    printk("\tAX=%04x  ", M.x86.R_AX);
400    printk("BX=%04x  ", M.x86.R_BX);
401    printk("CX=%04x  ", M.x86.R_CX);
402    printk("DX=%04x  ", M.x86.R_DX);
403    printk("SP=%04x  ", M.x86.R_SP);
404    printk("BP=%04x  ", M.x86.R_BP);
405    printk("SI=%04x  ", M.x86.R_SI);
406    printk("DI=%04x\n", M.x86.R_DI);
407    printk("\tDS=%04x  ", M.x86.R_DS);
408    printk("ES=%04x  ", M.x86.R_ES);
409    printk("SS=%04x  ", M.x86.R_SS);
410    printk("CS=%04x  ", M.x86.R_CS);
411    printk("IP=%04x   ", M.x86.R_IP);
412    if (ACCESS_FLAG(F_OF))
413        printk("OV ");          /* CHECKED... */
414    else
415        printk("NV ");
416    if (ACCESS_FLAG(F_DF))
417        printk("DN ");
418    else
419        printk("UP ");
420    if (ACCESS_FLAG(F_IF))
421        printk("EI ");
422    else
423        printk("DI ");
424    if (ACCESS_FLAG(F_SF))
425        printk("NG ");
426    else
427        printk("PL ");
428    if (ACCESS_FLAG(F_ZF))
429        printk("ZR ");
430    else
431        printk("NZ ");
432    if (ACCESS_FLAG(F_AF))
433        printk("AC ");
434    else
435        printk("NA ");
436    if (ACCESS_FLAG(F_PF))
437        printk("PE ");
438    else
439        printk("PO ");
440    if (ACCESS_FLAG(F_CF))
441        printk("CY ");
442    else
443        printk("NC ");
444    printk("\n");
445}
446
447void
448x86emu_dump_xregs(void)
449{
450    printk("\tEAX=%08x  ", M.x86.R_EAX);
451    printk("EBX=%08x  ", M.x86.R_EBX);
452    printk("ECX=%08x  ", M.x86.R_ECX);
453    printk("EDX=%08x  \n", M.x86.R_EDX);
454    printk("\tESP=%08x  ", M.x86.R_ESP);
455    printk("EBP=%08x  ", M.x86.R_EBP);
456    printk("ESI=%08x  ", M.x86.R_ESI);
457    printk("EDI=%08x\n", M.x86.R_EDI);
458    printk("\tDS=%04x  ", M.x86.R_DS);
459    printk("ES=%04x  ", M.x86.R_ES);
460    printk("SS=%04x  ", M.x86.R_SS);
461    printk("CS=%04x  ", M.x86.R_CS);
462    printk("EIP=%08x\n\t", M.x86.R_EIP);
463    if (ACCESS_FLAG(F_OF))
464        printk("OV ");          /* CHECKED... */
465    else
466        printk("NV ");
467    if (ACCESS_FLAG(F_DF))
468        printk("DN ");
469    else
470        printk("UP ");
471    if (ACCESS_FLAG(F_IF))
472        printk("EI ");
473    else
474        printk("DI ");
475    if (ACCESS_FLAG(F_SF))
476        printk("NG ");
477    else
478        printk("PL ");
479    if (ACCESS_FLAG(F_ZF))
480        printk("ZR ");
481    else
482        printk("NZ ");
483    if (ACCESS_FLAG(F_AF))
484        printk("AC ");
485    else
486        printk("NA ");
487    if (ACCESS_FLAG(F_PF))
488        printk("PE ");
489    else
490        printk("PO ");
491    if (ACCESS_FLAG(F_CF))
492        printk("CY ");
493    else
494        printk("NC ");
495    printk("\n");
496}
497