}
+static uint8_t
+getRestoredITBits(ThreadContext *tc, CPSR spsr)
+{
+ // See: shared/functions/system/RestoredITBits in the ARM ARM
+
+ const ExceptionLevel el = opModeToEL((OperatingMode) (uint8_t)spsr.mode);
+ const uint8_t it = itState(spsr);
+
+ if (!spsr.t || spsr.il)
+ return 0;
+
+ // The IT bits are forced to zero when they are set to a reserved
+ // value.
+ if (bits(it, 7, 4) != 0 && bits(it, 3, 0) == 0)
+ return 0;
+
+ const bool itd = el == EL2 ?
+ ((SCTLR)tc->readMiscReg(MISCREG_HSCTLR)).itd :
+ ((SCTLR)tc->readMiscReg(MISCREG_SCTLR)).itd;
+
+ // The IT bits are forced to zero when returning to A32 state, or
+ // when returning to an EL with the ITD bit set to 1, and the IT
+ // bits are describing a multi-instruction block.
+ if (itd && bits(it, 2, 0) != 0)
+ return 0;
+
+ return it;
+}
+
+static bool
+illegalExceptionReturn(ThreadContext *tc, CPSR cpsr, CPSR spsr)
+{
+ const OperatingMode mode = (OperatingMode) (uint8_t)spsr.mode;
+ if (badMode(mode))
+ return true;
+
+ const OperatingMode cur_mode = (OperatingMode) (uint8_t)cpsr.mode;
+ const ExceptionLevel target_el = opModeToEL(mode);
+ if (target_el > opModeToEL(cur_mode))
+ return true;
+
+ if (target_el == EL3 && !ArmSystem::haveSecurity(tc))
+ return true;
+
+ if (target_el == EL2 && !ArmSystem::haveVirtualization(tc))
+ return true;
+
+ if (!spsr.width) {
+ // aarch64
+ if (!ArmSystem::highestELIs64(tc))
+ return true;
+
+ if (spsr & 0x2)
+ return true;
+ if (target_el == EL0 && spsr.sp)
+ return true;
+ if (target_el == EL2 && !((SCR)tc->readMiscReg(MISCREG_SCR_EL3)).ns)
+ return false;
+ } else {
+ return badMode32(mode);
+ }
+
+ return false;
+}
+
+CPSR
+ArmStaticInst::getPSTATEFromPSR(ThreadContext *tc, CPSR cpsr, CPSR spsr) const
+{
+ CPSR new_cpsr = 0;
+
+ // gem5 doesn't implement single-stepping, so force the SS bit to
+ // 0.
+ new_cpsr.ss = 0;
+
+ if (illegalExceptionReturn(tc, cpsr, spsr)) {
+ new_cpsr.il = 1;
+ } else {
+ new_cpsr.il = spsr.il;
+ if (spsr.width && badMode32((OperatingMode)(uint8_t)spsr.mode)) {
+ new_cpsr.il = 1;
+ } else if (spsr.width) {
+ new_cpsr.mode = spsr.mode;
+ } else {
+ new_cpsr.el = spsr.el;
+ new_cpsr.sp = spsr.sp;
+ }
+ }
+
+ new_cpsr.nz = spsr.nz;
+ new_cpsr.c = spsr.c;
+ new_cpsr.v = spsr.v;
+ if (new_cpsr.width) {
+ // aarch32
+ const ITSTATE it = getRestoredITBits(tc, spsr);
+ new_cpsr.q = spsr.q;
+ new_cpsr.ge = spsr.ge;
+ new_cpsr.e = spsr.e;
+ new_cpsr.aif = spsr.aif;
+ new_cpsr.t = spsr.t;
+ new_cpsr.it2 = it.top6;
+ new_cpsr.it1 = it.bottom2;
+ } else {
+ // aarch64
+ new_cpsr.daif = spsr.daif;
+ }
+
+ return new_cpsr;
+}
+
+
+
}
NSACR nsacr, FPEXC fpexc,
bool fpexc_check, bool advsimd) const;
+ /**
+ * Get the new PSTATE from a SPSR register in preparation for an
+ * exception return.
+ *
+ * See shared/functions/system/SetPSTATEFromPSR in the ARM ARM
+ * psueodcode library.
+ */
+ CPSR getPSTATEFromPSR(ThreadContext *tc, CPSR cpsr, CPSR spsr) const;
+
public:
virtual void
annotateFault(ArmFault *fault) {}
// -*- mode:c++ -*-
-// Copyright (c) 2011-2013 ARM Limited
+// Copyright (c) 2011-2013, 2016 ARM Limited
// All rights reserved
//
// The license below extends only to copyright in the software and shall
else
newPc = newPc & ~mask(2);
}
- spsr.q = 0;
- spsr.it1 = 0;
- spsr.j = 0;
- spsr.res0_23_22 = 0;
- spsr.ge = 0;
- spsr.it2 = 0;
- spsr.t = 0;
-
- OperatingMode mode = (OperatingMode) (uint8_t) spsr.mode;
- bool illegal = false;
- ExceptionLevel target_el;
- if (badMode(mode)) {
- illegal = true;
- } else {
- target_el = opModeToEL(mode);
- if (((target_el == EL2) &&
- !ArmSystem::haveVirtualization(xc->tcBase())) ||
- (target_el > curr_el) ||
- (spsr.width == 1)) {
- illegal = true;
- } else {
- bool known = true;
- bool from32 = (spsr.width == 1);
- bool to32 = false;
- if (false) { // TODO: !haveAArch32EL
- to32 = false;
- } else if (!ArmSystem::highestELIs64(xc->tcBase())) {
- to32 = true;
- } else {
- bool scr_rw, hcr_rw;
- if (ArmSystem::haveSecurity(xc->tcBase())) {
- SCR scr = xc->tcBase()->readMiscReg(MISCREG_SCR_EL3);
- scr_rw = scr.rw;
- } else {
- scr_rw = true;
- }
-
- if (ArmSystem::haveVirtualization(xc->tcBase())) {
- HCR hcr = xc->tcBase()->readMiscReg(MISCREG_HCR_EL2);
- hcr_rw = hcr.rw;
- } else {
- hcr_rw = scr_rw;
- }
-
- switch (target_el) {
- case EL3:
- to32 = false;
- break;
- case EL2:
- to32 = !scr_rw;
- break;
- case EL1:
- to32 = !scr_rw || !hcr_rw;
- break;
- case EL0:
- if (curr_el == EL0) {
- to32 = cpsr.width;
- } else if (!scr_rw || !hcr_rw) {
- // EL0 using AArch32 if EL1 using AArch32
- to32 = true;
- } else {
- known = false;
- to32 = false;
- }
- }
- }
- if (known)
- illegal = (from32 != to32);
- }
- }
- if (illegal) {
- uint8_t old_mode = cpsr.mode;
- spsr.mode = old_mode; // Preserve old mode when invalid
- spsr.il = 1;
- } else {
- if (cpsr.width != spsr.width)
- panic("AArch32/AArch64 interprocessing not supported yet");
- }
- Cpsr = spsr;
+ CPSR new_cpsr = getPSTATEFromPSR(xc->tcBase(), cpsr, spsr);
- CondCodesNZ = spsr.nz;
- CondCodesC = spsr.c;
- CondCodesV = spsr.v;
+ Cpsr = new_cpsr;
+ CondCodesNZ = new_cpsr.nz;
+ CondCodesC = new_cpsr.c;
+ CondCodesV = new_cpsr.v;
+
+ NextAArch64 = !new_cpsr.width;
+ NextItState = itState(new_cpsr);
NPC = purifyTaggedAddr(newPc, xc->tcBase(),
- opModeToEL((OperatingMode) (uint8_t) spsr.mode));
+ opModeToEL((OperatingMode) (uint8_t) new_cpsr.mode));
+
LLSCLock = 0; // Clear exclusive monitor
SevMailbox = 1; //Set Event Register
'''
'NextJazelle': pcStateReg('nextJazelle', srtMode),
'NextItState': pcStateReg('nextItstate', srtMode),
'Itstate': pcStateReg('itstate', srtMode),
+ 'NextAArch64': pcStateReg('nextAArch64', srtMode),
#Register operands depending on a field in the instruction encoding. These
#should be avoided since they may not be portable across different
Bitfield<8> a;
Bitfield<7> i;
Bitfield<6> f;
+ Bitfield<8, 6> aif;
Bitfield<9, 6> daif; // AArch64
Bitfield<5> t;
Bitfield<4> width; // AArch64
/*
- * Copyright (c) 2010, 2012-2013 ARM Limited
+ * Copyright (c) 2010, 2012-2013, 2016 ARM Limited
* All rights reserved
*
* The license below extends only to copyright in the software and shall
bool isBigEndian64(ThreadContext *tc);
+static inline uint8_t
+itState(CPSR psr)
+{
+ ITSTATE it = 0;
+ it.top6 = psr.it2;
+ it.bottom2 = psr.it1;
+
+ return (uint8_t)it;
+}
+
/**
* Removes the tag from tagged addresses if that mode is enabled.
* @param addr The address to be purified.
projects / gem5.git / commitdiff