8d05292667
* wrapper.c (op_print): New function. (sim_dis_read): New function. (print_insn): New function - disassembles the given instruction. (sim_trace): Note that tracing is now allowed. (sim_create_inferior): Default to emulating v6. Initialise the disassembler machinery. (sim_target_parse_command_line): Add support for -t -d and -z options. (sim_target_display_usage): Note existence of -d and -z options. (sim_open): Parse -t -d and -z options. * armemu.h: Add exports of trace, disas and trace_funcs. Add prototype for print_insn. * armemu.c (ARMul_Emulate26): Add tracing code. Delete unused variables. * thumbemu (handle_v6_thumb_insn): Delete unused variable Rd. Move Rm variable into switch cases. Add tracing code. * armcopro.c (XScale_cp15_init): Add a return value. (XScale_cp13_init): Likewise. (XScale_cp14_init): Likewise. (XScale_cp15_LDC): Delete unused function. (XScale_cp15_STC): Likewise. * maverick.c: Delete comment inside comment. (DSPInit): Delete unused function. (DSPMCR4): Fix compile time warning about missing parenthesis. (DSPMCR5): Likewise. (DSPCDP6): Delete unused variable opcode2.
635 lines
18 KiB
C
635 lines
18 KiB
C
/* thumbemu.c -- Thumb instruction emulation.
|
|
Copyright (C) 1996, Cygnus Software Technologies Ltd.
|
|
|
|
This program is free software; you can redistribute it and/or modify
|
|
it under the terms of the GNU General Public License as published by
|
|
the Free Software Foundation; either version 3 of the License, or
|
|
(at your option) any later version.
|
|
|
|
This program is distributed in the hope that it will be useful,
|
|
but WITHOUT ANY WARRANTY; without even the implied warranty of
|
|
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
|
|
GNU General Public License for more details.
|
|
|
|
You should have received a copy of the GNU General Public License
|
|
along with this program; if not, see <http://www.gnu.org/licenses/>. */
|
|
|
|
/* We can provide simple Thumb simulation by decoding the Thumb
|
|
instruction into its corresponding ARM instruction, and using the
|
|
existing ARM simulator. */
|
|
|
|
#ifndef MODET /* required for the Thumb instruction support */
|
|
#if 1
|
|
#error "MODET needs to be defined for the Thumb world to work"
|
|
#else
|
|
#define MODET (1)
|
|
#endif
|
|
#endif
|
|
|
|
#include "armdefs.h"
|
|
#include "armemu.h"
|
|
#include "armos.h"
|
|
|
|
/* Attempt to emulate an ARMv6 instruction.
|
|
Stores t_branch into PVALUE upon success or t_undefined otherwise. */
|
|
|
|
static void
|
|
handle_v6_thumb_insn (ARMul_State * state,
|
|
ARMword tinstr,
|
|
tdstate * pvalid)
|
|
{
|
|
if (! state->is_v6)
|
|
{
|
|
* pvalid = t_undefined;
|
|
return;
|
|
}
|
|
|
|
switch (tinstr & 0xFFC0)
|
|
{
|
|
case 0xb660: /* cpsie */
|
|
case 0xb670: /* cpsid */
|
|
case 0x4600: /* cpy */
|
|
case 0xba00: /* rev */
|
|
case 0xba40: /* rev16 */
|
|
case 0xbac0: /* revsh */
|
|
case 0xb650: /* setend */
|
|
default:
|
|
printf ("Unhandled v6 thumb insn: %04x\n", tinstr);
|
|
* pvalid = t_undefined;
|
|
return;
|
|
|
|
case 0xb200: /* sxth */
|
|
{
|
|
ARMword Rm = state->Reg [(tinstr & 0x38) >> 3];
|
|
|
|
if (Rm & 0x8000)
|
|
state->Reg [(tinstr & 0x7)] = (Rm & 0xffff) | 0xffff0000;
|
|
else
|
|
state->Reg [(tinstr & 0x7)] = Rm & 0xffff;
|
|
break;
|
|
}
|
|
|
|
case 0xb240: /* sxtb */
|
|
{
|
|
ARMword Rm = state->Reg [(tinstr & 0x38) >> 3];
|
|
|
|
if (Rm & 0x80)
|
|
state->Reg [(tinstr & 0x7)] = (Rm & 0xff) | 0xffffff00;
|
|
else
|
|
state->Reg [(tinstr & 0x7)] = Rm & 0xff;
|
|
break;
|
|
}
|
|
|
|
case 0xb280: /* uxth */
|
|
{
|
|
ARMword Rm = state->Reg [(tinstr & 0x38) >> 3];
|
|
|
|
state->Reg [(tinstr & 0x7)] = Rm & 0xffff;
|
|
break;
|
|
}
|
|
|
|
case 0xb2c0: /* uxtb */
|
|
{
|
|
ARMword Rm = state->Reg [(tinstr & 0x38) >> 3];
|
|
|
|
state->Reg [(tinstr & 0x7)] = Rm & 0xff;
|
|
break;
|
|
}
|
|
}
|
|
/* Indicate that the instruction has been processed. */
|
|
* pvalid = t_branch;
|
|
}
|
|
|
|
/* Decode a 16bit Thumb instruction. The instruction is in the low
|
|
16-bits of the tinstr field, with the following Thumb instruction
|
|
held in the high 16-bits. Passing in two Thumb instructions allows
|
|
easier simulation of the special dual BL instruction. */
|
|
|
|
tdstate
|
|
ARMul_ThumbDecode (ARMul_State * state,
|
|
ARMword pc,
|
|
ARMword tinstr,
|
|
ARMword * ainstr)
|
|
{
|
|
tdstate valid = t_decoded; /* default assumes a valid instruction */
|
|
ARMword next_instr;
|
|
|
|
if (state->bigendSig)
|
|
{
|
|
next_instr = tinstr & 0xFFFF;
|
|
tinstr >>= 16;
|
|
}
|
|
else
|
|
{
|
|
next_instr = tinstr >> 16;
|
|
tinstr &= 0xFFFF;
|
|
}
|
|
|
|
if (trace)
|
|
fprintf (stderr, "pc: %x, Thumb instr: %x", pc & ~1, tinstr);
|
|
|
|
#if 1 /* debugging to catch non updates */
|
|
*ainstr = 0xDEADC0DE;
|
|
#endif
|
|
|
|
switch ((tinstr & 0xF800) >> 11)
|
|
{
|
|
case 0: /* LSL */
|
|
case 1: /* LSR */
|
|
case 2: /* ASR */
|
|
/* Format 1 */
|
|
*ainstr = 0xE1B00000 /* base opcode */
|
|
| ((tinstr & 0x1800) >> (11 - 5)) /* shift type */
|
|
| ((tinstr & 0x07C0) << (7 - 6)) /* imm5 */
|
|
| ((tinstr & 0x0038) >> 3) /* Rs */
|
|
| ((tinstr & 0x0007) << 12); /* Rd */
|
|
break;
|
|
case 3: /* ADD/SUB */
|
|
/* Format 2 */
|
|
{
|
|
ARMword subset[4] = {
|
|
0xE0900000, /* ADDS Rd,Rs,Rn */
|
|
0xE0500000, /* SUBS Rd,Rs,Rn */
|
|
0xE2900000, /* ADDS Rd,Rs,#imm3 */
|
|
0xE2500000 /* SUBS Rd,Rs,#imm3 */
|
|
};
|
|
/* It is quicker indexing into a table, than performing switch
|
|
or conditionals: */
|
|
*ainstr = subset[(tinstr & 0x0600) >> 9] /* base opcode */
|
|
| ((tinstr & 0x01C0) >> 6) /* Rn or imm3 */
|
|
| ((tinstr & 0x0038) << (16 - 3)) /* Rs */
|
|
| ((tinstr & 0x0007) << (12 - 0)); /* Rd */
|
|
}
|
|
break;
|
|
case 4: /* MOV */
|
|
case 5: /* CMP */
|
|
case 6: /* ADD */
|
|
case 7: /* SUB */
|
|
/* Format 3 */
|
|
{
|
|
ARMword subset[4] = {
|
|
0xE3B00000, /* MOVS Rd,#imm8 */
|
|
0xE3500000, /* CMP Rd,#imm8 */
|
|
0xE2900000, /* ADDS Rd,Rd,#imm8 */
|
|
0xE2500000, /* SUBS Rd,Rd,#imm8 */
|
|
};
|
|
*ainstr = subset[(tinstr & 0x1800) >> 11] /* base opcode */
|
|
| ((tinstr & 0x00FF) >> 0) /* imm8 */
|
|
| ((tinstr & 0x0700) << (16 - 8)) /* Rn */
|
|
| ((tinstr & 0x0700) << (12 - 8)); /* Rd */
|
|
}
|
|
break;
|
|
case 8: /* Arithmetic and high register transfers */
|
|
/* TODO: Since the subsets for both Format 4 and Format 5
|
|
instructions are made up of different ARM encodings, we could
|
|
save the following conditional, and just have one large
|
|
subset. */
|
|
if ((tinstr & (1 << 10)) == 0)
|
|
{
|
|
/* Format 4 */
|
|
struct
|
|
{
|
|
ARMword opcode;
|
|
enum
|
|
{ t_norm, t_shift, t_neg, t_mul }
|
|
otype;
|
|
}
|
|
subset[16] =
|
|
{
|
|
{ 0xE0100000, t_norm}, /* ANDS Rd,Rd,Rs */
|
|
{ 0xE0300000, t_norm}, /* EORS Rd,Rd,Rs */
|
|
{ 0xE1B00010, t_shift}, /* MOVS Rd,Rd,LSL Rs */
|
|
{ 0xE1B00030, t_shift}, /* MOVS Rd,Rd,LSR Rs */
|
|
{ 0xE1B00050, t_shift}, /* MOVS Rd,Rd,ASR Rs */
|
|
{ 0xE0B00000, t_norm}, /* ADCS Rd,Rd,Rs */
|
|
{ 0xE0D00000, t_norm}, /* SBCS Rd,Rd,Rs */
|
|
{ 0xE1B00070, t_shift}, /* MOVS Rd,Rd,ROR Rs */
|
|
{ 0xE1100000, t_norm}, /* TST Rd,Rs */
|
|
{ 0xE2700000, t_neg}, /* RSBS Rd,Rs,#0 */
|
|
{ 0xE1500000, t_norm}, /* CMP Rd,Rs */
|
|
{ 0xE1700000, t_norm}, /* CMN Rd,Rs */
|
|
{ 0xE1900000, t_norm}, /* ORRS Rd,Rd,Rs */
|
|
{ 0xE0100090, t_mul} , /* MULS Rd,Rd,Rs */
|
|
{ 0xE1D00000, t_norm}, /* BICS Rd,Rd,Rs */
|
|
{ 0xE1F00000, t_norm} /* MVNS Rd,Rs */
|
|
};
|
|
*ainstr = subset[(tinstr & 0x03C0) >> 6].opcode; /* base */
|
|
switch (subset[(tinstr & 0x03C0) >> 6].otype)
|
|
{
|
|
case t_norm:
|
|
*ainstr |= ((tinstr & 0x0007) << 16) /* Rn */
|
|
| ((tinstr & 0x0007) << 12) /* Rd */
|
|
| ((tinstr & 0x0038) >> 3); /* Rs */
|
|
break;
|
|
case t_shift:
|
|
*ainstr |= ((tinstr & 0x0007) << 12) /* Rd */
|
|
| ((tinstr & 0x0007) >> 0) /* Rm */
|
|
| ((tinstr & 0x0038) << (8 - 3)); /* Rs */
|
|
break;
|
|
case t_neg:
|
|
*ainstr |= ((tinstr & 0x0007) << 12) /* Rd */
|
|
| ((tinstr & 0x0038) << (16 - 3)); /* Rn */
|
|
break;
|
|
case t_mul:
|
|
*ainstr |= ((tinstr & 0x0007) << 16) /* Rd */
|
|
| ((tinstr & 0x0007) << 8) /* Rs */
|
|
| ((tinstr & 0x0038) >> 3); /* Rm */
|
|
break;
|
|
}
|
|
}
|
|
else
|
|
{
|
|
/* Format 5 */
|
|
ARMword Rd = ((tinstr & 0x0007) >> 0);
|
|
ARMword Rs = ((tinstr & 0x0038) >> 3);
|
|
if (tinstr & (1 << 7))
|
|
Rd += 8;
|
|
if (tinstr & (1 << 6))
|
|
Rs += 8;
|
|
switch ((tinstr & 0x03C0) >> 6)
|
|
{
|
|
case 0x1: /* ADD Rd,Rd,Hs */
|
|
case 0x2: /* ADD Hd,Hd,Rs */
|
|
case 0x3: /* ADD Hd,Hd,Hs */
|
|
*ainstr = 0xE0800000 /* base */
|
|
| (Rd << 16) /* Rn */
|
|
| (Rd << 12) /* Rd */
|
|
| (Rs << 0); /* Rm */
|
|
break;
|
|
case 0x5: /* CMP Rd,Hs */
|
|
case 0x6: /* CMP Hd,Rs */
|
|
case 0x7: /* CMP Hd,Hs */
|
|
*ainstr = 0xE1500000 /* base */
|
|
| (Rd << 16) /* Rn */
|
|
| (Rd << 12) /* Rd */
|
|
| (Rs << 0); /* Rm */
|
|
break;
|
|
case 0x9: /* MOV Rd,Hs */
|
|
case 0xA: /* MOV Hd,Rs */
|
|
case 0xB: /* MOV Hd,Hs */
|
|
*ainstr = 0xE1A00000 /* base */
|
|
| (Rd << 16) /* Rn */
|
|
| (Rd << 12) /* Rd */
|
|
| (Rs << 0); /* Rm */
|
|
break;
|
|
case 0xC: /* BX Rs */
|
|
case 0xD: /* BX Hs */
|
|
*ainstr = 0xE12FFF10 /* base */
|
|
| ((tinstr & 0x0078) >> 3); /* Rd */
|
|
break;
|
|
case 0xE: /* UNDEFINED */
|
|
case 0xF: /* UNDEFINED */
|
|
if (state->is_v5)
|
|
{
|
|
/* BLX Rs; BLX Hs */
|
|
*ainstr = 0xE12FFF30 /* base */
|
|
| ((tinstr & 0x0078) >> 3); /* Rd */
|
|
break;
|
|
}
|
|
/* Drop through. */
|
|
case 0x0: /* UNDEFINED */
|
|
case 0x4: /* UNDEFINED */
|
|
case 0x8: /* UNDEFINED */
|
|
handle_v6_thumb_insn (state, tinstr, & valid);
|
|
break;
|
|
}
|
|
}
|
|
break;
|
|
case 9: /* LDR Rd,[PC,#imm8] */
|
|
/* Format 6 */
|
|
*ainstr = 0xE59F0000 /* base */
|
|
| ((tinstr & 0x0700) << (12 - 8)) /* Rd */
|
|
| ((tinstr & 0x00FF) << (2 - 0)); /* off8 */
|
|
break;
|
|
case 10:
|
|
case 11:
|
|
/* TODO: Format 7 and Format 8 perform the same ARM encoding, so
|
|
the following could be merged into a single subset, saving on
|
|
the following boolean: */
|
|
if ((tinstr & (1 << 9)) == 0)
|
|
{
|
|
/* Format 7 */
|
|
ARMword subset[4] = {
|
|
0xE7800000, /* STR Rd,[Rb,Ro] */
|
|
0xE7C00000, /* STRB Rd,[Rb,Ro] */
|
|
0xE7900000, /* LDR Rd,[Rb,Ro] */
|
|
0xE7D00000 /* LDRB Rd,[Rb,Ro] */
|
|
};
|
|
*ainstr = subset[(tinstr & 0x0C00) >> 10] /* base */
|
|
| ((tinstr & 0x0007) << (12 - 0)) /* Rd */
|
|
| ((tinstr & 0x0038) << (16 - 3)) /* Rb */
|
|
| ((tinstr & 0x01C0) >> 6); /* Ro */
|
|
}
|
|
else
|
|
{
|
|
/* Format 8 */
|
|
ARMword subset[4] = {
|
|
0xE18000B0, /* STRH Rd,[Rb,Ro] */
|
|
0xE19000D0, /* LDRSB Rd,[Rb,Ro] */
|
|
0xE19000B0, /* LDRH Rd,[Rb,Ro] */
|
|
0xE19000F0 /* LDRSH Rd,[Rb,Ro] */
|
|
};
|
|
*ainstr = subset[(tinstr & 0x0C00) >> 10] /* base */
|
|
| ((tinstr & 0x0007) << (12 - 0)) /* Rd */
|
|
| ((tinstr & 0x0038) << (16 - 3)) /* Rb */
|
|
| ((tinstr & 0x01C0) >> 6); /* Ro */
|
|
}
|
|
break;
|
|
case 12: /* STR Rd,[Rb,#imm5] */
|
|
case 13: /* LDR Rd,[Rb,#imm5] */
|
|
case 14: /* STRB Rd,[Rb,#imm5] */
|
|
case 15: /* LDRB Rd,[Rb,#imm5] */
|
|
/* Format 9 */
|
|
{
|
|
ARMword subset[4] = {
|
|
0xE5800000, /* STR Rd,[Rb,#imm5] */
|
|
0xE5900000, /* LDR Rd,[Rb,#imm5] */
|
|
0xE5C00000, /* STRB Rd,[Rb,#imm5] */
|
|
0xE5D00000 /* LDRB Rd,[Rb,#imm5] */
|
|
};
|
|
/* The offset range defends on whether we are transferring a
|
|
byte or word value: */
|
|
*ainstr = subset[(tinstr & 0x1800) >> 11] /* base */
|
|
| ((tinstr & 0x0007) << (12 - 0)) /* Rd */
|
|
| ((tinstr & 0x0038) << (16 - 3)) /* Rb */
|
|
| ((tinstr & 0x07C0) >> (6 - ((tinstr & (1 << 12)) ? 0 : 2))); /* off5 */
|
|
}
|
|
break;
|
|
case 16: /* STRH Rd,[Rb,#imm5] */
|
|
case 17: /* LDRH Rd,[Rb,#imm5] */
|
|
/* Format 10 */
|
|
*ainstr = ((tinstr & (1 << 11)) /* base */
|
|
? 0xE1D000B0 /* LDRH */
|
|
: 0xE1C000B0) /* STRH */
|
|
| ((tinstr & 0x0007) << (12 - 0)) /* Rd */
|
|
| ((tinstr & 0x0038) << (16 - 3)) /* Rb */
|
|
| ((tinstr & 0x01C0) >> (6 - 1)) /* off5, low nibble */
|
|
| ((tinstr & 0x0600) >> (9 - 8)); /* off5, high nibble */
|
|
break;
|
|
case 18: /* STR Rd,[SP,#imm8] */
|
|
case 19: /* LDR Rd,[SP,#imm8] */
|
|
/* Format 11 */
|
|
*ainstr = ((tinstr & (1 << 11)) /* base */
|
|
? 0xE59D0000 /* LDR */
|
|
: 0xE58D0000) /* STR */
|
|
| ((tinstr & 0x0700) << (12 - 8)) /* Rd */
|
|
| ((tinstr & 0x00FF) << 2); /* off8 */
|
|
break;
|
|
case 20: /* ADD Rd,PC,#imm8 */
|
|
case 21: /* ADD Rd,SP,#imm8 */
|
|
/* Format 12 */
|
|
if ((tinstr & (1 << 11)) == 0)
|
|
{
|
|
/* NOTE: The PC value used here should by word aligned */
|
|
/* We encode shift-left-by-2 in the rotate immediate field,
|
|
so no shift of off8 is needed. */
|
|
*ainstr = 0xE28F0F00 /* base */
|
|
| ((tinstr & 0x0700) << (12 - 8)) /* Rd */
|
|
| (tinstr & 0x00FF); /* off8 */
|
|
}
|
|
else
|
|
{
|
|
/* We encode shift-left-by-2 in the rotate immediate field,
|
|
so no shift of off8 is needed. */
|
|
*ainstr = 0xE28D0F00 /* base */
|
|
| ((tinstr & 0x0700) << (12 - 8)) /* Rd */
|
|
| (tinstr & 0x00FF); /* off8 */
|
|
}
|
|
break;
|
|
case 22:
|
|
case 23:
|
|
switch (tinstr & 0x0F00)
|
|
{
|
|
case 0x0000:
|
|
/* Format 13 */
|
|
/* NOTE: The instruction contains a shift left of 2
|
|
equivalent (implemented as ROR #30): */
|
|
*ainstr = ((tinstr & (1 << 7)) /* base */
|
|
? 0xE24DDF00 /* SUB */
|
|
: 0xE28DDF00) /* ADD */
|
|
| (tinstr & 0x007F); /* off7 */
|
|
break;
|
|
case 0x0400:
|
|
/* Format 14 - Push */
|
|
* ainstr = 0xE92D0000 | (tinstr & 0x00FF);
|
|
break;
|
|
case 0x0500:
|
|
/* Format 14 - Push + LR */
|
|
* ainstr = 0xE92D4000 | (tinstr & 0x00FF);
|
|
break;
|
|
case 0x0c00:
|
|
/* Format 14 - Pop */
|
|
* ainstr = 0xE8BD0000 | (tinstr & 0x00FF);
|
|
break;
|
|
case 0x0d00:
|
|
/* Format 14 - Pop + PC */
|
|
* ainstr = 0xE8BD8000 | (tinstr & 0x00FF);
|
|
break;
|
|
case 0x0e00:
|
|
if (state->is_v5)
|
|
{
|
|
/* This is normally an undefined instruction. The v5t architecture
|
|
defines this particular pattern as a BKPT instruction, for
|
|
hardware assisted debugging. We map onto the arm BKPT
|
|
instruction. */
|
|
* ainstr = 0xE1200070 | ((tinstr & 0xf0) << 4) | (tinstr & 0xf);
|
|
break;
|
|
}
|
|
/* Drop through. */
|
|
default:
|
|
/* Everything else is an undefined instruction. */
|
|
handle_v6_thumb_insn (state, tinstr, & valid);
|
|
break;
|
|
}
|
|
break;
|
|
case 24: /* STMIA */
|
|
case 25: /* LDMIA */
|
|
/* Format 15 */
|
|
*ainstr = ((tinstr & (1 << 11)) /* base */
|
|
? 0xE8B00000 /* LDMIA */
|
|
: 0xE8A00000) /* STMIA */
|
|
| ((tinstr & 0x0700) << (16 - 8)) /* Rb */
|
|
| (tinstr & 0x00FF); /* mask8 */
|
|
break;
|
|
case 26: /* Bcc */
|
|
case 27: /* Bcc/SWI */
|
|
if ((tinstr & 0x0F00) == 0x0F00)
|
|
{
|
|
/* Format 17 : SWI */
|
|
*ainstr = 0xEF000000;
|
|
/* Breakpoint must be handled specially. */
|
|
if ((tinstr & 0x00FF) == 0x18)
|
|
*ainstr |= ((tinstr & 0x00FF) << 16);
|
|
/* New breakpoint value. See gdb/arm-tdep.c */
|
|
else if ((tinstr & 0x00FF) == 0xFE)
|
|
*ainstr |= SWI_Breakpoint;
|
|
else
|
|
*ainstr |= (tinstr & 0x00FF);
|
|
}
|
|
else if ((tinstr & 0x0F00) != 0x0E00)
|
|
{
|
|
/* Format 16 */
|
|
int doit = FALSE;
|
|
/* TODO: Since we are doing a switch here, we could just add
|
|
the SWI and undefined instruction checks into this
|
|
switch to same on a couple of conditionals: */
|
|
switch ((tinstr & 0x0F00) >> 8)
|
|
{
|
|
case EQ:
|
|
doit = ZFLAG;
|
|
break;
|
|
case NE:
|
|
doit = !ZFLAG;
|
|
break;
|
|
case VS:
|
|
doit = VFLAG;
|
|
break;
|
|
case VC:
|
|
doit = !VFLAG;
|
|
break;
|
|
case MI:
|
|
doit = NFLAG;
|
|
break;
|
|
case PL:
|
|
doit = !NFLAG;
|
|
break;
|
|
case CS:
|
|
doit = CFLAG;
|
|
break;
|
|
case CC:
|
|
doit = !CFLAG;
|
|
break;
|
|
case HI:
|
|
doit = (CFLAG && !ZFLAG);
|
|
break;
|
|
case LS:
|
|
doit = (!CFLAG || ZFLAG);
|
|
break;
|
|
case GE:
|
|
doit = ((!NFLAG && !VFLAG) || (NFLAG && VFLAG));
|
|
break;
|
|
case LT:
|
|
doit = ((NFLAG && !VFLAG) || (!NFLAG && VFLAG));
|
|
break;
|
|
case GT:
|
|
doit = ((!NFLAG && !VFLAG && !ZFLAG)
|
|
|| (NFLAG && VFLAG && !ZFLAG));
|
|
break;
|
|
case LE:
|
|
doit = ((NFLAG && !VFLAG) || (!NFLAG && VFLAG)) || ZFLAG;
|
|
break;
|
|
}
|
|
if (doit)
|
|
{
|
|
state->Reg[15] = (pc + 4
|
|
+ (((tinstr & 0x7F) << 1)
|
|
| ((tinstr & (1 << 7)) ? 0xFFFFFF00 : 0)));
|
|
FLUSHPIPE;
|
|
}
|
|
valid = t_branch;
|
|
}
|
|
else
|
|
/* UNDEFINED : cc=1110(AL) uses different format. */
|
|
handle_v6_thumb_insn (state, tinstr, & valid);
|
|
break;
|
|
case 28: /* B */
|
|
/* Format 18 */
|
|
state->Reg[15] = (pc + 4
|
|
+ (((tinstr & 0x3FF) << 1)
|
|
| ((tinstr & (1 << 10)) ? 0xFFFFF800 : 0)));
|
|
FLUSHPIPE;
|
|
valid = t_branch;
|
|
break;
|
|
case 29: /* UNDEFINED */
|
|
if (state->is_v5)
|
|
{
|
|
if (tinstr & 1)
|
|
{
|
|
handle_v6_thumb_insn (state, tinstr, & valid);
|
|
break;
|
|
}
|
|
/* Drop through. */
|
|
|
|
/* Format 19 */
|
|
/* There is no single ARM instruction equivalent for this
|
|
instruction. Also, it should only ever be matched with the
|
|
fmt19 "BL/BLX instruction 1" instruction. However, we do
|
|
allow the simulation of it on its own, with undefined results
|
|
if r14 is not suitably initialised. */
|
|
{
|
|
ARMword tmp = (pc + 2);
|
|
|
|
state->Reg[15] = ((state->Reg[14] + ((tinstr & 0x07FF) << 1))
|
|
& 0xFFFFFFFC);
|
|
CLEART;
|
|
state->Reg[14] = (tmp | 1);
|
|
valid = t_branch;
|
|
FLUSHPIPE;
|
|
if (trace_funcs)
|
|
fprintf (stderr, " pc changed to %x\n", state->Reg[15]);
|
|
break;
|
|
}
|
|
}
|
|
|
|
handle_v6_thumb_insn (state, tinstr, & valid);
|
|
break;
|
|
|
|
case 30: /* BL instruction 1 */
|
|
/* Format 19 */
|
|
/* There is no single ARM instruction equivalent for this Thumb
|
|
instruction. To keep the simulation simple (from the user
|
|
perspective) we check if the following instruction is the
|
|
second half of this BL, and if it is we simulate it
|
|
immediately. */
|
|
state->Reg[14] = state->Reg[15] \
|
|
+ (((tinstr & 0x07FF) << 12) \
|
|
| ((tinstr & (1 << 10)) ? 0xFF800000 : 0));
|
|
|
|
valid = t_branch; /* in-case we don't have the 2nd half */
|
|
tinstr = next_instr; /* move the instruction down */
|
|
pc += 2; /* point the pc at the 2nd half */
|
|
if (((tinstr & 0xF800) >> 11) != 31)
|
|
{
|
|
if (((tinstr & 0xF800) >> 11) == 29)
|
|
{
|
|
ARMword tmp = (pc + 2);
|
|
|
|
state->Reg[15] = ((state->Reg[14]
|
|
+ ((tinstr & 0x07FE) << 1))
|
|
& 0xFFFFFFFC);
|
|
CLEART;
|
|
state->Reg[14] = (tmp | 1);
|
|
valid = t_branch;
|
|
FLUSHPIPE;
|
|
}
|
|
else
|
|
/* Exit, since not correct instruction. */
|
|
pc -= 2;
|
|
break;
|
|
}
|
|
/* else we fall through to process the second half of the BL */
|
|
pc += 2; /* point the pc at the 2nd half */
|
|
case 31: /* BL instruction 2 */
|
|
/* Format 19 */
|
|
/* There is no single ARM instruction equivalent for this
|
|
instruction. Also, it should only ever be matched with the
|
|
fmt19 "BL instruction 1" instruction. However, we do allow
|
|
the simulation of it on its own, with undefined results if
|
|
r14 is not suitably initialised. */
|
|
{
|
|
ARMword tmp = pc;
|
|
|
|
state->Reg[15] = (state->Reg[14] + ((tinstr & 0x07FF) << 1));
|
|
state->Reg[14] = (tmp | 1);
|
|
valid = t_branch;
|
|
FLUSHPIPE;
|
|
}
|
|
break;
|
|
}
|
|
|
|
if (trace && valid != t_decoded)
|
|
fprintf (stderr, "\n");
|
|
|
|
return valid;
|
|
}
|