/****************************************************************************
*
* Realmode X86 Emulator Library
*
* Copyright (C) 1996-1999 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 "x86emu/x86emui.h"
#include <stdarg.h>
#include <stdlib.h>
/*----------------------------- Implementation ----------------------------*/
#ifdef DEBUG
static void print_encoded_bytes (u16 s, u16 o);
static void print_decoded_instruction (void);
static int parse_line (char *s, int *ps, int *n);
/* should look something like debug's output. */
void X86EMU_trace_regs (void)
{
if (DEBUG_TRACE()) {
x86emu_dump_regs();
}
if (DEBUG_DECODE() && ! DEBUG_DECODE_NOPRINT()) {
printk("%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!
*/
printk("%04x:%04x ",M.x86.saved_cs, M.x86.saved_ip);
print_encoded_bytes( M.x86.saved_cs, M.x86.saved_ip);
print_decoded_instruction();
}
static 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 (char *x)
{
sprintf(M.x86.decoded_buf+M.x86.enc_str_pos,"%s",x);
M.x86.enc_str_pos += strlen(x);
}
void x86emu_decode_printf2 (char *x, int y)
{
char temp[100];
sprintf(temp,x,y);
sprintf(M.x86.decoded_buf+M.x86.enc_str_pos,"%s",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++) {
sprintf(buf1+2*i,"%02x", fetch_data_byte_abs(s,o+i));
}
printk("%-20s",buf1);
}
static void print_decoded_instruction (void)
{
printk("%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);
printk("%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;
u32 current;
current = start;
while (end <= off + amt) {
printk("%04x:%04x ", seg, start);
for (i=start; i< off; i++)
printk(" ");
for ( ; i< end; i++)
printk("%02x ", fetch_data_byte_abs(seg,i));
printk("\n");
start = end;
end = start + 16;
}
}
void x86emu_single_step (void)
{
char s[1024];
int ps[10];
int ntok;
int cmd;
int done;
int segment;
int offset;
static int breakpoint;
static int noDecode = 1;
char *p;
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) {
printk("-");
/*p = fgets(s, 1023, stdin); */
cons_gets(s);
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];
printk("breakpoint set to 0x%X\n", breakpoint);
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;
printk("Toggled decoding to %s\n",(noDecode)?"FALSE":"TRUE");
break;
case 't':
case 0:
done = 1;
break;
}
}
}
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);
}
static int parse_line (char *s, int *ps, int *n)
{
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++;
ps[*n]=atoi(s);
/*sscanf(s,"%x",&ps[*n]); */
*n += 1;
}
}
#endif /* DEBUG */
void x86emu_dump_stack(void)
{
int i;
printk("Stack: ");
for (i = 0; i<16; i++)
{
u8 x = fetch_data_byte_abs(M.x86.R_SS, M.x86.R_SP + i);
printk("%02x ", (int)x);
}
printk("\n");
}
void x86emu_dump_regs (void)
{
printk("\tAX=%04x ", M.x86.R_AX );
printk("BX=%04x ", M.x86.R_BX );
printk("CX=%04x ", M.x86.R_CX );
printk("DX=%04x ", M.x86.R_DX );
printk("SP=%04x ", M.x86.R_SP );
printk("BP=%04x ", M.x86.R_BP );
printk("SI=%04x ", M.x86.R_SI );
printk("DI=%04x\n", M.x86.R_DI );
printk("\tDS=%04x ", M.x86.R_DS );
printk("ES=%04x ", M.x86.R_ES );
printk("SS=%04x ", M.x86.R_SS );
printk("CS=%04x ", M.x86.R_CS );
printk("IP=%04x ", M.x86.R_IP );
if (ACCESS_FLAG(F_OF)) printk("OV "); /* CHECKED... */
else printk("NV ");
if (ACCESS_FLAG(F_DF)) printk("DN ");
else printk("UP ");
if (ACCESS_FLAG(F_IF)) printk("EI ");
else printk("DI ");
if (ACCESS_FLAG(F_SF)) printk("NG ");
else printk("PL ");
if (ACCESS_FLAG(F_ZF)) printk("ZR ");
else printk("NZ ");
if (ACCESS_FLAG(F_AF)) printk("AC ");
else printk("NA ");
if (ACCESS_FLAG(F_PF)) printk("PE ");
else printk("PO ");
if (ACCESS_FLAG(F_CF)) printk("CY ");
else printk("NC ");
printk("\n");
/*x86emu_dump_stack(); */
}
void x86emu_dump_xregs (void)
{
printk("\tEAX=%08x ", M.x86.R_EAX );
printk("EBX=%08x ", M.x86.R_EBX );
printk("ECX=%08x ", M.x86.R_ECX );
printk("EDX=%08x \n", M.x86.R_EDX );
printk("\tESP=%08x ", M.x86.R_ESP );
printk("EBP=%08x ", M.x86.R_EBP );
printk("ESI=%08x ", M.x86.R_ESI );
printk("EDI=%08x\n", M.x86.R_EDI );
printk("\tDS=%04x ", M.x86.R_DS );
printk("ES=%04x ", M.x86.R_ES );
printk("SS=%04x ", M.x86.R_SS );
printk("CS=%04x ", M.x86.R_CS );
printk("EIP=%08x\n\t", M.x86.R_EIP );
if (ACCESS_FLAG(F_OF)) printk("OV "); /* CHECKED... */
else printk("NV ");
if (ACCESS_FLAG(F_DF)) printk("DN ");
else printk("UP ");
if (ACCESS_FLAG(F_IF)) printk("EI ");
else printk("DI ");
if (ACCESS_FLAG(F_SF)) printk("NG ");
else printk("PL ");
if (ACCESS_FLAG(F_ZF)) printk("ZR ");
else printk("NZ ");
if (ACCESS_FLAG(F_AF)) printk("AC ");
else printk("NA ");
if (ACCESS_FLAG(F_PF)) printk("PE ");
else printk("PO ");
if (ACCESS_FLAG(F_CF)) printk("CY ");
else printk("NC ");
printk("\n");
}
