/** Write some register to memory.
* This will store some register and meta data onto the virtual stack.
* The address for the write
* \param state [in/out] The unwinding state.
* \param wAddr [in] The address at which to write the data.
* \param reg [in] The register to store.
* \return TRUE if the write was successful, FALSE otherwise.
*/
Boolean UnwMemWriteRegister(UnwState * const state,
const Int32 addr,
const RegData * const reg)
{
return UnwMemHashWrite(&state->memData,
addr,
reg->v,
M_IsOriginValid(reg->o));
}
UnwResult UnwStartThumb(UnwState * const state)
{
Boolean found = FALSE;
Int16 t = UNW_MAX_INSTR_COUNT;
do
{
Int16 instr;
/* Attempt to read the instruction */
if(!state->cb->readH(state->regData[15].v & (~0x1), &instr))
{
return UNWIND_IREAD_H_FAIL;
}
UnwPrintd4("T %x %x %04x:",
state->regData[13].v, state->regData[15].v, instr);
/* Check that the PC is still on Thumb alignment */
if(!(state->regData[15].v & 0x1))
{
UnwPrintd1("\nError: PC misalignment\n");
return UNWIND_INCONSISTENT;
}
/* Check that the SP and PC have not been invalidated */
if(!M_IsOriginValid(state->regData[13].o) || !M_IsOriginValid(state->regData[15].o))
{
UnwPrintd1("\nError: PC or SP invalidated\n");
return UNWIND_INCONSISTENT;
}
/* Format 1: Move shifted register
* LSL Rd, Rs, #Offset5
* LSR Rd, Rs, #Offset5
* ASR Rd, Rs, #Offset5
*/
if((instr & 0xe000) == 0x0000 && (instr & 0x1800) != 0x1800)
{
Boolean signExtend;
Int8 op = (instr & 0x1800) >> 11;
Int8 offset5 = (instr & 0x07c0) >> 6;
Int8 rs = (instr & 0x0038) >> 3;
Int8 rd = (instr & 0x0007);
switch(op)
{
case 0: /* LSL */
UnwPrintd6("LSL r%d, r%d, #%d\t; r%d %s", rd, rs, offset5, rs, M_Origin2Str(state->regData[rs].o));
state->regData[rd].v = state->regData[rs].v << offset5;
state->regData[rd].o = state->regData[rs].o;
state->regData[rd].o |= REG_VAL_ARITHMETIC;
break;
case 1: /* LSR */
UnwPrintd6("LSR r%d, r%d, #%d\t; r%d %s", rd, rs, offset5, rs, M_Origin2Str(state->regData[rs].o));
state->regData[rd].v = state->regData[rs].v >> offset5;
state->regData[rd].o = state->regData[rs].o;
state->regData[rd].o |= REG_VAL_ARITHMETIC;
break;
case 2: /* ASR */
UnwPrintd6("ASL r%d, r%d, #%d\t; r%d %s", rd, rs, offset5, rs, M_Origin2Str(state->regData[rs].o));
signExtend = (state->regData[rs].v & 0x8000) ? TRUE : FALSE;
state->regData[rd].v = state->regData[rs].v >> offset5;
if(signExtend)
{
state->regData[rd].v |= 0xffffffff << (32 - offset5);
}
state->regData[rd].o = state->regData[rs].o;
state->regData[rd].o |= REG_VAL_ARITHMETIC;
break;
}
}
/* Format 2: add/subtract
* ADD Rd, Rs, Rn
* ADD Rd, Rs, #Offset3
* SUB Rd, Rs, Rn
* SUB Rd, Rs, #Offset3
*/
else if((instr & 0xf800) == 0x1800)
{
Boolean I = (instr & 0x0400) ? TRUE : FALSE;
Boolean op = (instr & 0x0200) ? TRUE : FALSE;
Int8 rn = (instr & 0x01c0) >> 6;
Int8 rs = (instr & 0x0038) >> 3;
Int8 rd = (instr & 0x0007);
/* Print decoding */
UnwPrintd6("%s r%d, r%d, %c%d\t;",
op ? "SUB" : "ADD",
rd, rs,
I ? '#' : 'r',
rn);
UnwPrintd5("r%d %s, r%d %s",
rd, M_Origin2Str(state->regData[rd].o),
rs, M_Origin2Str(state->regData[rs].o));
if(!I)
{
UnwPrintd3(", r%d %s", rn, M_Origin2Str(state->regData[rn].o));
/* Perform calculation */
if(op)
{
state->regData[rd].v = state->regData[rs].v - state->regData[rn].v;
}
else
{
state->regData[rd].v = state->regData[rs].v + state->regData[rn].v;
}
/* Propagate the origin */
if(M_IsOriginValid(state->regData[rs].v) &&
M_IsOriginValid(state->regData[rn].v))
{
state->regData[rd].o = state->regData[rs].o;
state->regData[rd].o |= REG_VAL_ARITHMETIC;
}
else
{
state->regData[rd].o = REG_VAL_INVALID;
}
}
else
{
/* Perform calculation */
if(op)
{
state->regData[rd].v = state->regData[rs].v - rn;
}
else
{
state->regData[rd].v = state->regData[rs].v + rn;
}
/* Propagate the origin */
state->regData[rd].o = state->regData[rs].o;
state->regData[rd].o |= REG_VAL_ARITHMETIC;
}
}
