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 ****************************************************************************/
42 #if defined(CONFIG_BIOSEMU)
44 #include "x86emu/x86emui.h"
46 /*----------------------------- Implementation ----------------------------*/
50 static void print_encoded_bytes(u16 s, u16 o);
51 static void print_decoded_instruction(void);
52 static int parse_line(char *s, int *ps, int *n);
54 /* should look something like debug's output. */
55 void X86EMU_trace_regs(void)
60 if (DEBUG_DECODE() && !DEBUG_DECODE_NOPRINT()) {
61 printk("%04x:%04x ", M.x86.saved_cs, M.x86.saved_ip);
62 print_encoded_bytes(M.x86.saved_cs, M.x86.saved_ip);
63 print_decoded_instruction();
67 void X86EMU_trace_xregs(void)
74 void x86emu_just_disassemble(void)
77 * This routine called if the flag DEBUG_DISASSEMBLE is set kind
80 printk("%04x:%04x ", M.x86.saved_cs, M.x86.saved_ip);
81 print_encoded_bytes(M.x86.saved_cs, M.x86.saved_ip);
82 print_decoded_instruction();
85 static void disassemble_forward(u16 seg, u16 off, int n)
91 * hack, hack, hack. What we do is use the exact machinery set up
92 * for execution, except that now there is an additional state
93 * flag associated with the "execution", and we are using a copy
94 * of the register struct. All the major opcodes, once fully
95 * decoded, have the following two steps: TRACE_REGS(r,m);
96 * SINGLE_STEP(r,m); which disappear if DEBUG is not defined to
97 * the preprocessor. The TRACE_REGS macro expands to:
99 * if (debug&DEBUG_DISASSEMBLE)
100 * {just_disassemble(); goto EndOfInstruction;}
101 * if (debug&DEBUG_TRACE) trace_regs(r,m);
103 * ...... and at the last line of the routine.
105 * EndOfInstruction: end_instr();
107 * Up to the point where TRACE_REG is expanded, NO modifications
108 * are done to any register EXCEPT the IP register, for fetch and
111 * This was done for an entirely different reason, but makes a
112 * nice way to get the system to help debug codes.
115 tregs.x86.R_IP = off;
116 tregs.x86.R_CS = seg;
118 /* reset the decoding buffers */
119 tregs.x86.enc_str_pos = 0;
120 tregs.x86.enc_pos = 0;
122 /* turn on the "disassemble only, no execute" flag */
123 tregs.x86.debug |= DEBUG_DISASSEMBLE_F;
125 /* DUMP NEXT n instructions to screen in straight_line fashion */
127 * This looks like the regular instruction fetch stream, except
128 * that when this occurs, each fetched opcode, upon seeing the
129 * DEBUG_DISASSEMBLE flag set, exits immediately after decoding
130 * the instruction. XXX --- CHECK THAT MEM IS NOT AFFECTED!!!
131 * Note the use of a copy of the register structure...
133 for (i = 0; i < n; i++) {
134 op1 = (*sys_rdb) (((u32) M.x86.R_CS << 4) + (M.x86.R_IP++));
135 (x86emu_optab[op1]) (op1);
137 /* end major hack mode. */
140 void x86emu_check_ip_access(void)
145 void x86emu_check_sp_access(void)
149 void x86emu_check_mem_access(u32 dummy)
151 /* check bounds, etc */
154 void x86emu_check_data_access(uint dummy1, uint dummy2)
156 /* check bounds, etc */
159 void x86emu_inc_decoded_inst_len(int x)
164 void x86emu_decode_printf(char *x)
166 sprintf(M.x86.decoded_buf + M.x86.enc_str_pos, "%s", x);
167 M.x86.enc_str_pos += strlen(x);
170 void x86emu_decode_printf2(char *x, int y)
174 sprintf(M.x86.decoded_buf + M.x86.enc_str_pos, "%s", temp);
175 M.x86.enc_str_pos += strlen(temp);
178 void x86emu_end_instr(void)
180 M.x86.enc_str_pos = 0;
184 static void print_encoded_bytes(u16 s, u16 o)
188 for (i = 0; i < M.x86.enc_pos; i++) {
189 sprintf(buf1 + 2 * i, "%02x", fetch_data_byte_abs(s, o + i));
191 printk("%-20s", buf1);
194 static void print_decoded_instruction(void)
196 printk("%s", M.x86.decoded_buf);
199 void x86emu_print_int_vect(u16 iv)
205 seg = fetch_data_word_abs(0, iv * 4);
206 off = fetch_data_word_abs(0, iv * 4 + 2);
207 printk("%04x:%04x ", seg, off);
210 void X86EMU_dump_memory(u16 seg, u16 off, u32 amt)
212 u32 start = off & 0xfffffff0;
213 u32 end = (off + 16) & 0xfffffff0;
218 while (end <= off + amt) {
219 printk("%04x:%04x ", seg, start);
220 for (i = start; i < off; i++)
223 printk("%02x ", fetch_data_byte_abs(seg, i));
230 void x86emu_single_step(void)
239 static int breakpoint;
240 static int noDecode = 1;
245 if (M.x86.saved_ip != breakpoint) {
248 M.x86.debug &= ~DEBUG_DECODE_NOPRINT_F;
249 M.x86.debug |= DEBUG_TRACE_F;
250 M.x86.debug &= ~DEBUG_BREAK_F;
251 print_decoded_instruction();
256 offset = M.x86.saved_ip;
259 cmd = parse_line(s, ps, &ntok);
262 disassemble_forward(M.x86.saved_cs, (u16) offset, 10);
266 segment = M.x86.saved_cs;
268 X86EMU_dump_memory(segment, (u16) offset, 16);
270 } else if (ntok == 3) {
273 X86EMU_dump_memory(segment, (u16) offset, 16);
276 segment = M.x86.saved_cs;
277 X86EMU_dump_memory(segment, (u16) offset, 16);
282 M.x86.debug ^= DEBUG_TRACECALL_F;
286 DEBUG_SVC_F | DEBUG_SYS_F | DEBUG_SYSINT_F;
292 X86EMU_trace_xregs();
298 M.x86.debug |= DEBUG_DECODE_NOPRINT_F;
300 M.x86.debug &= ~DEBUG_DECODE_NOPRINT_F;
302 M.x86.debug &= ~DEBUG_TRACE_F;
303 M.x86.debug |= DEBUG_BREAK_F;
308 M.x86.debug |= DEBUG_EXIT;
311 noDecode = (noDecode) ? 0 : 1;
312 printk("Toggled decoding to %s\n",
313 (noDecode) ? "FALSE" : "TRUE");
323 int X86EMU_trace_on(void)
325 return M.x86.debug |= DEBUG_STEP_F | DEBUG_DECODE_F | DEBUG_TRACE_F;
328 int X86EMU_trace_off(void)
330 return M.x86.debug &= ~(DEBUG_STEP_F | DEBUG_DECODE_F | DEBUG_TRACE_F);
333 static int parse_line(char *s, int *ps, int *n)
338 while (*s == ' ' || *s == '\t')
351 while (*s != ' ' && *s != '\t' && *s != '\n')
357 while (*s == ' ' || *s == '\t')
366 void x86emu_dump_regs(void)
368 printk("\tAX=%04x ", M.x86.R_AX);
369 printk("BX=%04x ", M.x86.R_BX);
370 printk("CX=%04x ", M.x86.R_CX);
371 printk("DX=%04x ", M.x86.R_DX);
372 printk("SP=%04x ", M.x86.R_SP);
373 printk("BP=%04x ", M.x86.R_BP);
374 printk("SI=%04x ", M.x86.R_SI);
375 printk("DI=%04x\n", M.x86.R_DI);
376 printk("\tDS=%04x ", M.x86.R_DS);
377 printk("ES=%04x ", M.x86.R_ES);
378 printk("SS=%04x ", M.x86.R_SS);
379 printk("CS=%04x ", M.x86.R_CS);
380 printk("IP=%04x ", M.x86.R_IP);
381 if (ACCESS_FLAG(F_OF))
382 printk("OV "); /* CHECKED... */
385 if (ACCESS_FLAG(F_DF))
389 if (ACCESS_FLAG(F_IF))
393 if (ACCESS_FLAG(F_SF))
397 if (ACCESS_FLAG(F_ZF))
401 if (ACCESS_FLAG(F_AF))
405 if (ACCESS_FLAG(F_PF))
409 if (ACCESS_FLAG(F_CF))
416 void x86emu_dump_xregs(void)
418 printk("\tEAX=%08x ", M.x86.R_EAX);
419 printk("EBX=%08x ", M.x86.R_EBX);
420 printk("ECX=%08x ", M.x86.R_ECX);
421 printk("EDX=%08x \n", M.x86.R_EDX);
422 printk("\tESP=%08x ", M.x86.R_ESP);
423 printk("EBP=%08x ", M.x86.R_EBP);
424 printk("ESI=%08x ", M.x86.R_ESI);
425 printk("EDI=%08x\n", M.x86.R_EDI);
426 printk("\tDS=%04x ", M.x86.R_DS);
427 printk("ES=%04x ", M.x86.R_ES);
428 printk("SS=%04x ", M.x86.R_SS);
429 printk("CS=%04x ", M.x86.R_CS);
430 printk("EIP=%08x\n\t", M.x86.R_EIP);
431 if (ACCESS_FLAG(F_OF))
432 printk("OV "); /* CHECKED... */
435 if (ACCESS_FLAG(F_DF))
439 if (ACCESS_FLAG(F_IF))
443 if (ACCESS_FLAG(F_SF))
447 if (ACCESS_FLAG(F_ZF))
451 if (ACCESS_FLAG(F_AF))
455 if (ACCESS_FLAG(F_PF))
459 if (ACCESS_FLAG(F_CF))