void
cec_require_supervisor (SIM_CPU *cpu)
{
/* Do not call _cec_require_supervisor() to avoid CEC_STATE()
as that macro requires OS operating mode. */
if (cec_is_user_mode (cpu))
cec_exception (cpu, VEC_ILL_RES);
}
static sim_cia
step_once (SIM_CPU *cpu)
{
SIM_DESC sd = CPU_STATE (cpu);
bu32 insn_len, oldpc = PCREG;
int i;
bool ssstep;
if (TRACE_ANY_P (cpu))
trace_prefix (sd, cpu, NULL_CIA, oldpc, TRACE_LINENUM_P (cpu),
NULL, 0, " "); /* Use a space for gcc warnings. */
/* Handle hardware single stepping when lower than EVT3, and when SYSCFG
has already had the SSSTEP bit enabled. */
ssstep = false;
if (STATE_ENVIRONMENT (sd) == OPERATING_ENVIRONMENT
&& (SYSCFGREG & SYSCFG_SSSTEP))
{
int ivg = cec_get_ivg (cpu);
if (ivg == -1 || ivg > 3)
ssstep = true;
}
#if 0
/* XXX: Is this what happens on the hardware ? */
if (cec_get_ivg (cpu) == EVT_EMU)
cec_return (cpu, EVT_EMU);
#endif
BFIN_CPU_STATE.did_jump = false;
insn_len = interp_insn_bfin (cpu, oldpc);
/* If we executed this insn successfully, then we always decrement
the loop counter. We don't want to update the PC though if the
last insn happened to be a change in code flow (jump/etc...). */
if (!BFIN_CPU_STATE.did_jump)
SET_PCREG (hwloop_get_next_pc (cpu, oldpc, insn_len));
for (i = 1; i >= 0; --i)
if (LCREG (i) && oldpc == LBREG (i))
{
SET_LCREG (i, LCREG (i) - 1);
if (LCREG (i))
break;
}
++ PROFILE_TOTAL_INSN_COUNT (CPU_PROFILE_DATA (cpu));
/* Handle hardware single stepping only if we're still lower than EVT3.
XXX: May not be entirely correct wrt EXCPT insns. */
if (ssstep)
{
int ivg = cec_get_ivg (cpu);
if (ivg == -1 || ivg > 3)
{
INSN_LEN = 0;
cec_exception (cpu, VEC_STEP);
}
}
return oldpc;
}
void
cec_return (SIM_CPU *cpu, int ivg)
{
SIM_DESC sd = CPU_STATE (cpu);
struct bfin_cec *cec;
bool snen;
int curr_ivg;
bu32 oldpc, newpc;
oldpc = PCREG;
BFIN_CPU_STATE.did_jump = true;
if (STATE_ENVIRONMENT (sd) != OPERATING_ENVIRONMENT)
{
SET_PCREG (cec_read_ret_reg (cpu, ivg));
TRACE_BRANCH (cpu, oldpc, PCREG, -1, "CEC changed PC");
return;
}
cec = CEC_STATE (cpu);
/* XXX: This isn't entirely correct ... */
cec->ipend &= ~IVG_EMU_B;
curr_ivg = _cec_get_ivg (cec);
if (curr_ivg == -1)
curr_ivg = IVG_USER;
if (ivg == -1)
ivg = curr_ivg;
TRACE_EVENTS (cpu, "returning from EVT%i (should be EVT%i)", curr_ivg, ivg);
/* Not allowed to return from usermode. */
if (curr_ivg == IVG_USER)
cec_exception (cpu, VEC_ILL_RES);
if (ivg > IVG15 || ivg < 0)
sim_io_error (sd, "%s: ivg %i out of range !", __func__, ivg);
_cec_require_supervisor (cpu, cec);
switch (ivg)
{
case IVG_EMU:
/* RTE -- only valid in emulation mode. */
/* XXX: What does the hardware do ? */
if (curr_ivg != IVG_EMU)
cec_exception (cpu, VEC_ILL_RES);
break;
case IVG_NMI:
/* RTN -- only valid in NMI. */
/* XXX: What does the hardware do ? */
if (curr_ivg != IVG_NMI)
cec_exception (cpu, VEC_ILL_RES);
break;
case IVG_EVX:
/* RTX -- only valid in exception. */
/* XXX: What does the hardware do ? */
if (curr_ivg != IVG_EVX)
cec_exception (cpu, VEC_ILL_RES);
break;
default:
/* RTI -- not valid in emulation, nmi, exception, or user. */
/* XXX: What does the hardware do ? */
if (curr_ivg == IVG_EMU || curr_ivg == IVG_NMI
|| curr_ivg == IVG_EVX || curr_ivg == IVG_USER)
cec_exception (cpu, VEC_ILL_RES);
break;
case IVG_IRPTEN:
/* XXX: Is this even possible ? */
excp_to_sim_halt (sim_stopped, SIM_SIGABRT);
break;
}
newpc = cec_read_ret_reg (cpu, ivg);
/* XXX: Does this nested trick work on EMU/NMI/EVX ? */
snen = (newpc & 1);
/* XXX: Delayed clear shows bad PCREG register trace above ? */
SET_PCREG (newpc & ~1);
TRACE_BRANCH (cpu, oldpc, PCREG, -1, "CEC changed PC (from EVT%i)", ivg);
/* Update ipend after the TRACE_BRANCH so dv-bfin_trace
knows current CEC state wrt overflow. */
if (!snen)
cec->ipend &= ~(1 << ivg);
/* Disable global interrupt mask to let any interrupt take over, but
only when we were already in a RTI level. Only way we could have
raised at that point is if it was cleared in the first place. */
if (ivg >= IVG_IVHW || ivg == IVG_RST)
cec_irpten_disable (cpu, cec);
/* When going from super to user, we clear LSB in LB regs in case
it was set on the transition up.
Also need to load SP alias with USP. */
if (_cec_get_ivg (cec) == -1)
{
int i;
for (i = 0; i < 2; ++i)
if (LBREG (i) & 1)
SET_LBREG (i, LBREG (i) & ~1);
SET_KSPREG (SPREG);
SET_SPREG (USPREG);
}
/* Check for pending interrupts before we return to usermode. */
_cec_check_pending (cpu, cec);
}
static void
_cec_require_supervisor (SIM_CPU *cpu, struct bfin_cec *cec)
{
if (_cec_is_user_mode (cec))
cec_exception (cpu, VEC_ILL_RES);
}
