class SystemCallSequence(Sequence):
def __init__(self, aGenThread):
super().__init__(aGenThread)
self._mAssemblyHelper = AssemblyHelperRISCV(self)
self._mDataBlockAddrRegIndex = None
self._mActionCodeRegIndex = None
self._mAppRegSize = 64
def generate(self, **kwargs):
(handlers_set_name, valid) = self.getOption("handlers_set")
if valid and (handlers_set_name == "Fast"):
self.error(
"Fast exception handlers are enabled. SystemCallSequence only "
"supports using comprehensive exception handlers."
)
self._mAppRegSize = self.getGlobalState("AppRegisterWidth")
function = kwargs.setdefault("Function", "SwitchPrivilegeLevel")
if function == "SwitchPrivilegeLevel":
ret_code = self._switchPrivilegeLevel(kwargs)
else:
self.error("SystemCallSequence does not support the %s function" % function)
self._processReturnCode(ret_code, function)
# Execute a privilege level switch.
#
# @params aParams A dictionary of optional parameters.
# PrivilegeLevel: The target privilege level. Permissible values are
# 'U', 'S', 'M', 0, 1, 3 or 'Random'; defaults to 'Random'.
# TargetAddr: The address at which to resume execution after
# completing the privilege level switch. Permissible values are
# any 64-bit integer; defaults to a randomly generated valid
# instruction address.
# SkipAddrValidation: Specifies whether to skip validating a
# specified TargetAddr value. Permissible values are 0 or 1;
# defaults to 0. If SkipAddrValidation is 0, the TargetAddr value
# is checked to determine whether it is a valid instruction
# address. If it isn't, an alternative address is randomly
# generated. If SkipAddrValidation is 1, the target address value
# is always used as is.
# AddrChoicesModID: Specifies ID of choices modification set to be
# applied when generating the target address in the event no
# TargetAddr value is provided or the value provided is invalid.
# Permissible values are any valid choices modification set ID.
# InterruptMask: Value to set the xstatus.xIE field to for the target
# privilege level. Permissible values are 0, 1, 'Same', 'Flip' or
# 'Random'; defaults to 'Random'.
# SUM: *** Not currently supported! *** Value to set the xstatus.SUM
# field to for the target privilege level. Permissible values are
# 0, 1, 'Same', 'Flip' or 'Random'; defaults to 'Random'.
# MXR: *** Not currently supported! *** Value to set the xstatus.MXR
# field to for the target privilege level. Permissible values are
# 0, 1, 'Same', 'Flip' or 'Random'; defaults to 'Random'.
# MPRV: *** Not currently supported! *** Value to set the
# mstatus.MPRV field to for the target privilege level.
# Permissible values are 0, 1, 'Same', 'Flip' or 'Random';
# defaults to 'Random'. As this field is only relevant to M mode,
# it is ignored if the target privilege level is not M.
def _switchPrivilegeLevel(self, aParams):
except_request_results = self.exceptionRequest("SystemCall", aParams)
ret_code = except_request_results["RetCode"]
if ret_code != 0:
return ret_code
self._assignRegisters(
except_request_results["DataBlockAddrRegIndex"],
except_request_results["ActionCodeRegIndex"],
)
load_gpr64_seq = LoadGPR64(self.genThread)
load_gpr64_seq.load(
self._mDataBlockAddrRegIndex,
except_request_results["DataBlockAddr"],
)
self._genPrivilegeLevelSwitchInstructions(
except_request_results["InstrSeqCode"],
except_request_results["PrivilegeLevel"],
except_request_results["TargetAddr"],
except_request_results["IntermediateRetAddr"],
)
self._unassignRegisters()
self.genSequence("UpdatePeState", {"RecordId": except_request_results["RecordId"]})
self.updateVm()
return ret_code
# Output appropriate messages based on the return code. Fail if the return
# code is not 0 and NoSkip is specified.
#
# @param aRetCode The return code from the system call operation.
# @param aFunction The operation performed by the system call.
def _processReturnCode(self, aRetCode, aFunction):
if aRetCode == 0:
self.notice("SystemCallSequence request %s processed succesfully" % aFunction)
else:
self.notice(
"SystemCallSequence request %s could not be processed "
"successfully; return code %d" % (aFunction, aRetCode)
)
(no_skip, valid) = self.genThread.getOption("NoSkip")
if valid and (no_skip == 1) and (aRetCode != 0):
self.error(
"Unable to process SystemCallSequence request and NoSkip option was specified"
)
# Generate the instructions required to execute the privilege level switch.
#
# @param aInstrSeqCode A value indicating the instructions that need to be
# generated.
# @param aTargetPrivLevel The target privilege level.
# @param aTargetAddr The address at which to resume execution after
# completing the privilege level switch.
# @param aIntermediateRetAddr The return address for the first ECALL of a
# 2 ECALL sequence
def _genPrivilegeLevelSwitchInstructions(
self,
aInstrSeqCode,
aTargetPrivLevel,
aTargetAddr,
aIntermediateRetAddr,
):
if aInstrSeqCode == 0:
# Do nothing
pass
elif aInstrSeqCode == 1:
# Generate 1 ECALL instruction
action_code = 2 # Load From Data Block
self._mAssemblyHelper.genMoveImmediate(self._mActionCodeRegIndex, action_code)
self._genEcall()
elif aInstrSeqCode == 2:
# Generate xRET instruction
self._genXRet(aTargetPrivLevel, aTargetAddr)
elif aInstrSeqCode == 3:
# Generate 2 ECALL instructions
action_code = 1 # Return to S Mode
self._mAssemblyHelper.genMoveImmediate(self._mActionCodeRegIndex, action_code)
self._genEcall()
self.setPEstate("PrivilegeLevel", 1)
self.setPEstate("PC", aIntermediateRetAddr)
# For a 2 ECALL sequence, the data block contains a return address
# for the first ECALL as the first entry; after the first ECALL, we
# increment the data block address pointer to allow loading the
# data block as usual in the second ECALL
self._genIncrementDataBlockPointer()
action_code = 2 # Load From Data Block
self._mAssemblyHelper.genMoveImmediate(self._mActionCodeRegIndex, action_code)
self._genEcall()
else:
self.error("Unexpected InstrSeqCode value %d" % aInstrSeqCode)
# Assign registers to be used for executing the privilege level switch so
# that they can be referenced later.
#
# @param aDataBlockRegIndex The index of the register used for storing the
# data block address.
# @param aActionCodeRegIndex The index of the register used for storing
# the action code.
def _assignRegisters(self, aDataBlockRegIndex, aActionCodeRegIndex):
self._mDataBlockAddrRegIndex = aDataBlockRegIndex
self._mActionCodeRegIndex = aActionCodeRegIndex
# Clear register assignments.
def _unassignRegisters(self):
self._mActionCodeRegIndex = None
self._mDataBlockAddrRegIndex = None
# Generate an ECALL instruction.
def _genEcall(self):
self.genInstruction("ECALL##RISCV")
# Generate an xRET instruction.
#
# @param aTargetPrivLevel The target privilege level.
# @param aTargetAddr The address at which to resume execution after
# completing the privilege level switch.
def _genXRet(self, aTargetPrivLevel, aTargetAddr):
priv_level = self.getPEstate("PrivilegeLevel")
if priv_level == 1:
priv_level_prefix = "S"
elif priv_level == 3:
priv_level_prefix = "M"
else:
self.error(
"Unexpected request to execute xRET instruction to transition "
"from privilege level %s to privilege level %s" % (priv_level, aTargetPrivLevel)
)
# The action code register is used as a scratch register here to reduce
# the number of required registers
self._genLoadGPR(self._mActionCodeRegIndex, self._mDataBlockAddrRegIndex, 0)
self._mAssemblyHelper.genWriteSystemRegister(
("%sstatus" % priv_level_prefix.lower()), self._mActionCodeRegIndex
)
self._genLoadGPR(self._mActionCodeRegIndex, self._mDataBlockAddrRegIndex, 1)
self._mAssemblyHelper.genWriteSystemRegister(
("%sepc" % priv_level_prefix.lower()), self._mActionCodeRegIndex
)
self._genLoadGPR(self._mActionCodeRegIndex, self._mDataBlockAddrRegIndex, 2)
self._mAssemblyHelper.genWriteSystemRegister("satp", self._mActionCodeRegIndex)
self.genInstruction(("%sRET##RISCV" % priv_level_prefix), {"NoRestriction": 1})
# Generate an instruction to increment the data block address pointer.
def _genIncrementDataBlockPointer(self):
if self._mAppRegSize == 32:
self._mAssemblyHelper.genAddImmediate(self._mDataBlockAddrRegIndex, 4)
else:
self._mAssemblyHelper.genAddImmediate(self._mDataBlockAddrRegIndex, 8)
# Generate instruction to load a single GPR
#
# @param aDestReg - index of destination GPR
# @param aAddrReg - index of GPR containing base address
# @param aOffset - offset from base address
def _genLoadGPR(self, aDestReg, aAddrReg, aOffset=0):
if self._mAppRegSize == 32:
self.genInstruction(
"LW##RISCV",
{
"rd": aDestReg,
"rs1": aAddrReg,
"simm12": aOffset * 4,
"NoRestriction": 1,
},
)
else:
self.genInstruction(
"LD##RISCV",
{
"rd": aDestReg,
"rs1": aAddrReg,
"simm12": aOffset * 8,
"NoRestriction": 1,
},
)
def generate(self, **kargs):
assembly_helper = AssemblyHelperRISCV(self)
# TODO(Noah): Test branch instruction generation methods when there is time to do so.
(dest_reg_index, src_reg_index,
src_reg_index_2) = self.getRandomGPRs(3, exclude='0')
load_gpr64_seq = LoadGPR64(self.genThread)
src_reg_val = RandomUtils.random64()
load_gpr64_seq.load(src_reg_index, src_reg_val)
src_reg_val_2 = RandomUtils.random64()
load_gpr64_seq.load(src_reg_index_2, src_reg_val_2)
MAX_GPR_VAL = 0xFFFFFFFFFFFFFFFF
imm_val = RandomUtils.random32(0, 2047)
assembly_helper.genMoveImmediate(dest_reg_index, imm_val)
dest_reg_val = imm_val
exception_handlers_test_utils.assertGprHasValue(
self, dest_reg_index, dest_reg_val)
shift_amount = RandomUtils.random32(0, 63)
assembly_helper.genShiftLeftImmediate(dest_reg_index, shift_amount)
dest_reg_val = (dest_reg_val << shift_amount) & MAX_GPR_VAL
exception_handlers_test_utils.assertGprHasValue(
self, dest_reg_index, dest_reg_val)
shift_amount = RandomUtils.random32(0, 63)
assembly_helper.genShiftRightImmediate(dest_reg_index, shift_amount)
dest_reg_val = (dest_reg_val >> shift_amount) & MAX_GPR_VAL
exception_handlers_test_utils.assertGprHasValue(
self, dest_reg_index, dest_reg_val)
shift_amount = RandomUtils.random32(0, 63)
assembly_helper.genShiftLeftImmediate(dest_reg_index,
shift_amount,
aSrcRegIndex=src_reg_index)
dest_reg_val = (src_reg_val << shift_amount) & MAX_GPR_VAL
exception_handlers_test_utils.assertGprHasValue(
self, dest_reg_index, dest_reg_val)
shift_amount = RandomUtils.random32(0, 63)
assembly_helper.genShiftRightImmediate(dest_reg_index,
shift_amount,
aSrcRegIndex=src_reg_index)
dest_reg_val = (src_reg_val >> shift_amount) & MAX_GPR_VAL
exception_handlers_test_utils.assertGprHasValue(
self, dest_reg_index, dest_reg_val)
imm_val = RandomUtils.random32(0, 2047)
assembly_helper.genAndImmediate(dest_reg_index, imm_val)
dest_reg_val &= imm_val
exception_handlers_test_utils.assertGprHasValue(
self, dest_reg_index, dest_reg_val)
imm_val = RandomUtils.random32(0, 2047)
assembly_helper.genAndImmediate(dest_reg_index,
imm_val,
aSrcRegIndex=src_reg_index)
dest_reg_val = src_reg_val & imm_val
exception_handlers_test_utils.assertGprHasValue(
self, dest_reg_index, dest_reg_val)
imm_val = RandomUtils.random32(0, 2047)
assembly_helper.genOrImmediate(dest_reg_index, imm_val)
dest_reg_val |= imm_val
exception_handlers_test_utils.assertGprHasValue(
self, dest_reg_index, dest_reg_val)
imm_val = RandomUtils.random32(0, 2047)
assembly_helper.genOrImmediate(dest_reg_index,
imm_val,
aSrcRegIndex=src_reg_index)
dest_reg_val = src_reg_val | imm_val
exception_handlers_test_utils.assertGprHasValue(
self, dest_reg_index, dest_reg_val)
imm_val = RandomUtils.random32(0, 2047)
assembly_helper.genXorImmediate(dest_reg_index, imm_val)
dest_reg_val ^= imm_val
exception_handlers_test_utils.assertGprHasValue(
self, dest_reg_index, dest_reg_val)
imm_val = RandomUtils.random32(0, 2047)
assembly_helper.genXorImmediate(dest_reg_index,
imm_val,
aSrcRegIndex=src_reg_index)
dest_reg_val = src_reg_val ^ imm_val
exception_handlers_test_utils.assertGprHasValue(
self, dest_reg_index, dest_reg_val)
imm_val = RandomUtils.random32(0, 2047)
assembly_helper.genAddImmediate(dest_reg_index, imm_val)
dest_reg_val = (dest_reg_val + imm_val) & MAX_GPR_VAL
exception_handlers_test_utils.assertGprHasValue(
self, dest_reg_index, dest_reg_val)
imm_val = RandomUtils.random32(0, 2047)
assembly_helper.genAddImmediate(dest_reg_index,
imm_val,
aSrcRegIndex=src_reg_index)
dest_reg_val = (src_reg_val + imm_val) & MAX_GPR_VAL
exception_handlers_test_utils.assertGprHasValue(
self, dest_reg_index, dest_reg_val)
assembly_helper.genMoveRegister(dest_reg_index, src_reg_index)
dest_reg_val = src_reg_val
exception_handlers_test_utils.assertGprHasValue(
self, dest_reg_index, dest_reg_val)
# Reset destination register value after copying directly from source; otherwise, the tests
# that follow will be less interesting
dest_reg_val = RandomUtils.random64()
load_gpr64_seq.load(dest_reg_index, dest_reg_val)
assembly_helper.genAndRegister(dest_reg_index, src_reg_index)
dest_reg_val &= src_reg_val
exception_handlers_test_utils.assertGprHasValue(
self, dest_reg_index, dest_reg_val)
assembly_helper.genAndRegister(dest_reg_index,
src_reg_index,
aSrcRegIndex2=src_reg_index_2)
dest_reg_val = src_reg_val_2 & src_reg_val
exception_handlers_test_utils.assertGprHasValue(
self, dest_reg_index, dest_reg_val)
assembly_helper.genOrRegister(dest_reg_index, src_reg_index)
dest_reg_val |= src_reg_val
exception_handlers_test_utils.assertGprHasValue(
self, dest_reg_index, dest_reg_val)
assembly_helper.genOrRegister(dest_reg_index,
src_reg_index,
aSrcRegIndex2=src_reg_index_2)
dest_reg_val = src_reg_val_2 | src_reg_val
exception_handlers_test_utils.assertGprHasValue(
self, dest_reg_index, dest_reg_val)
assembly_helper.genNotRegister(dest_reg_index)
dest_reg_val = ~dest_reg_val & MAX_GPR_VAL
exception_handlers_test_utils.assertGprHasValue(
self, dest_reg_index, dest_reg_val)
assembly_helper.genNotRegister(dest_reg_index,
aSrcRegIndex=src_reg_index)
dest_reg_val = ~src_reg_val & MAX_GPR_VAL
exception_handlers_test_utils.assertGprHasValue(
self, dest_reg_index, dest_reg_val)
assembly_helper.genAddRegister(dest_reg_index, src_reg_index)
dest_reg_val = (dest_reg_val + src_reg_val) & MAX_GPR_VAL
exception_handlers_test_utils.assertGprHasValue(
self, dest_reg_index, dest_reg_val)
assembly_helper.genAddRegister(dest_reg_index,
src_reg_index,
aSrcRegIndex2=src_reg_index_2)
dest_reg_val = (src_reg_val_2 + src_reg_val) & MAX_GPR_VAL
exception_handlers_test_utils.assertGprHasValue(
self, dest_reg_index, dest_reg_val)
assembly_helper.genSubRegister(dest_reg_index, src_reg_index)
dest_reg_val = (dest_reg_val - src_reg_val) & MAX_GPR_VAL
exception_handlers_test_utils.assertGprHasValue(
self, dest_reg_index, dest_reg_val)
assembly_helper.genSubRegister(dest_reg_index,
src_reg_index,
aMinuendRegIndex=src_reg_index_2)
dest_reg_val = (src_reg_val_2 - src_reg_val) & MAX_GPR_VAL
exception_handlers_test_utils.assertGprHasValue(
self, dest_reg_index, dest_reg_val)
assembly_helper.genReadSystemRegister(dest_reg_index, 'mscratch')
(dest_reg_val, valid) = self.readRegister('mscratch')
if not valid:
self.error('Value for register mscratch is invalid')
exception_handlers_test_utils.assertGprHasValue(
self, dest_reg_index, dest_reg_val)
assembly_helper.genWriteSystemRegister('mscratch', src_reg_index)
(mscratch_val, valid) = self.readRegister('mscratch')
if not valid:
self.error('Value for register mscratch is invalid')
if mscratch_val != src_reg_val:
self.error(
'Value of register mscratch did not match the expected value. Expected=0x%x, Actual=0x%x'
% (src_reg_val, mscratch_val))
def generate(self, **kargs):
assembly_helper = AssemblyHelperRISCV(self)
appRegSize = self.getGlobalState("AppRegisterWidth")
if appRegSize == 32:
self.notice("FORCE/RISCV configured for 32-bits...")
else:
self.notice("FORCE/RISCV configured for 64-bits...")
(dest_reg_index, src_reg_index,
src_reg_index_2) = self.getRandomGPRs(3, exclude="0")
load_gpr64_seq = LoadGPR64(self.genThread)
src_reg_val = RandomUtils.random32(
) if appRegSize == 32 else RandomUtils.random64()
load_gpr64_seq.load(src_reg_index, src_reg_val)
src_reg_val_2 = RandomUtils.random32(
) if appRegSize == 32 else RandomUtils.random64()
load_gpr64_seq.load(src_reg_index_2, src_reg_val_2)
MAX_GPR_VAL = 0xFFFFFFFF if appRegSize == 32 else 0xFFFFFFFFFFFFFFFF
imm_val = RandomUtils.random32(0, 2047)
assembly_helper.genMoveImmediate(dest_reg_index, imm_val)
dest_reg_val = imm_val
exception_handlers_test_utils.assert_gpr_has_value(
self, dest_reg_index, dest_reg_val)
max_shift_val = 31 if appRegSize == 32 else 63
shift_amount = RandomUtils.random32(0, max_shift_val)
assembly_helper.genShiftLeftImmediate(dest_reg_index, shift_amount)
dest_reg_val = (dest_reg_val << shift_amount) & MAX_GPR_VAL
exception_handlers_test_utils.assert_gpr_has_value(
self, dest_reg_index, dest_reg_val)
shift_amount = RandomUtils.random32(0, max_shift_val)
assembly_helper.genShiftRightImmediate(dest_reg_index, shift_amount)
dest_reg_val = (dest_reg_val >> shift_amount) & MAX_GPR_VAL
exception_handlers_test_utils.assert_gpr_has_value(
self, dest_reg_index, dest_reg_val)
shift_amount = RandomUtils.random32(0, max_shift_val)
assembly_helper.genShiftLeftImmediate(dest_reg_index,
shift_amount,
aSrcRegIndex=src_reg_index)
dest_reg_val = (src_reg_val << shift_amount) & MAX_GPR_VAL
exception_handlers_test_utils.assert_gpr_has_value(
self, dest_reg_index, dest_reg_val)
shift_amount = RandomUtils.random32(0, max_shift_val)
assembly_helper.genShiftRightImmediate(dest_reg_index,
shift_amount,
aSrcRegIndex=src_reg_index)
dest_reg_val = (src_reg_val >> shift_amount) & MAX_GPR_VAL
exception_handlers_test_utils.assert_gpr_has_value(
self, dest_reg_index, dest_reg_val)
imm_val = RandomUtils.random32(0, 2047)
assembly_helper.genAndImmediate(dest_reg_index, imm_val)
dest_reg_val &= imm_val
exception_handlers_test_utils.assert_gpr_has_value(
self, dest_reg_index, dest_reg_val)
imm_val = RandomUtils.random32(0, 2047)
assembly_helper.genAndImmediate(dest_reg_index,
imm_val,
aSrcRegIndex=src_reg_index)
dest_reg_val = src_reg_val & imm_val
exception_handlers_test_utils.assert_gpr_has_value(
self, dest_reg_index, dest_reg_val)
imm_val = RandomUtils.random32(0, 2047)
assembly_helper.genOrImmediate(dest_reg_index, imm_val)
dest_reg_val |= imm_val
exception_handlers_test_utils.assert_gpr_has_value(
self, dest_reg_index, dest_reg_val)
imm_val = RandomUtils.random32(0, 2047)
assembly_helper.genOrImmediate(dest_reg_index,
imm_val,
aSrcRegIndex=src_reg_index)
dest_reg_val = src_reg_val | imm_val
exception_handlers_test_utils.assert_gpr_has_value(
self, dest_reg_index, dest_reg_val)
imm_val = RandomUtils.random32(0, 2047)
assembly_helper.genXorImmediate(dest_reg_index, imm_val)
dest_reg_val ^= imm_val
exception_handlers_test_utils.assert_gpr_has_value(
self, dest_reg_index, dest_reg_val)
imm_val = RandomUtils.random32(0, 2047)
assembly_helper.genXorImmediate(dest_reg_index,
imm_val,
aSrcRegIndex=src_reg_index)
dest_reg_val = src_reg_val ^ imm_val
exception_handlers_test_utils.assert_gpr_has_value(
self, dest_reg_index, dest_reg_val)
imm_val = RandomUtils.random32(0, 2047)
assembly_helper.genAddImmediate(dest_reg_index, imm_val)
dest_reg_val = (dest_reg_val + imm_val) & MAX_GPR_VAL
exception_handlers_test_utils.assert_gpr_has_value(
self, dest_reg_index, dest_reg_val)
imm_val = RandomUtils.random32(0, 2047)
assembly_helper.genAddImmediate(dest_reg_index,
imm_val,
aSrcRegIndex=src_reg_index)
dest_reg_val = (src_reg_val + imm_val) & MAX_GPR_VAL
exception_handlers_test_utils.assert_gpr_has_value(
self, dest_reg_index, dest_reg_val)
assembly_helper.genMoveRegister(dest_reg_index, src_reg_index)
dest_reg_val = src_reg_val
exception_handlers_test_utils.assert_gpr_has_value(
self, dest_reg_index, dest_reg_val)
# Reset destination register value after copying directly from source;
# otherwise, the tests that follow will be less interesting
dest_reg_val = RandomUtils.random32(
) if appRegSize == 32 else RandomUtils.random64()
load_gpr64_seq.load(dest_reg_index, dest_reg_val)
assembly_helper.genAndRegister(dest_reg_index, src_reg_index)
dest_reg_val &= src_reg_val
exception_handlers_test_utils.assert_gpr_has_value(
self, dest_reg_index, dest_reg_val)
assembly_helper.genAndRegister(dest_reg_index,
src_reg_index,
aSrcRegIndex2=src_reg_index_2)
dest_reg_val = src_reg_val_2 & src_reg_val
exception_handlers_test_utils.assert_gpr_has_value(
self, dest_reg_index, dest_reg_val)
assembly_helper.genOrRegister(dest_reg_index, src_reg_index)
dest_reg_val |= src_reg_val
exception_handlers_test_utils.assert_gpr_has_value(
self, dest_reg_index, dest_reg_val)
assembly_helper.genOrRegister(dest_reg_index,
src_reg_index,
aSrcRegIndex2=src_reg_index_2)
dest_reg_val = src_reg_val_2 | src_reg_val
exception_handlers_test_utils.assert_gpr_has_value(
self, dest_reg_index, dest_reg_val)
assembly_helper.genNotRegister(dest_reg_index)
dest_reg_val = ~dest_reg_val & MAX_GPR_VAL
exception_handlers_test_utils.assert_gpr_has_value(
self, dest_reg_index, dest_reg_val)
assembly_helper.genNotRegister(dest_reg_index,
aSrcRegIndex=src_reg_index)
dest_reg_val = ~src_reg_val & MAX_GPR_VAL
exception_handlers_test_utils.assert_gpr_has_value(
self, dest_reg_index, dest_reg_val)
assembly_helper.genAddRegister(dest_reg_index, src_reg_index)
dest_reg_val = (dest_reg_val + src_reg_val) & MAX_GPR_VAL
exception_handlers_test_utils.assert_gpr_has_value(
self, dest_reg_index, dest_reg_val)
assembly_helper.genAddRegister(dest_reg_index,
src_reg_index,
aSrcRegIndex2=src_reg_index_2)
dest_reg_val = (src_reg_val_2 + src_reg_val) & MAX_GPR_VAL
exception_handlers_test_utils.assert_gpr_has_value(
self, dest_reg_index, dest_reg_val)
assembly_helper.genSubRegister(dest_reg_index, src_reg_index)
dest_reg_val = (dest_reg_val - src_reg_val) & MAX_GPR_VAL
exception_handlers_test_utils.assert_gpr_has_value(
self, dest_reg_index, dest_reg_val)
assembly_helper.genSubRegister(dest_reg_index,
src_reg_index,
aMinuendRegIndex=src_reg_index_2)
dest_reg_val = (src_reg_val_2 - src_reg_val) & MAX_GPR_VAL
exception_handlers_test_utils.assert_gpr_has_value(
self, dest_reg_index, dest_reg_val)
assembly_helper.genReadSystemRegister(dest_reg_index, "mscratch")
(dest_reg_val, valid) = self.readRegister("mscratch")
if not valid:
self.error("Value for register mscratch is invalid")
exception_handlers_test_utils.assert_gpr_has_value(
self, dest_reg_index, dest_reg_val)
assembly_helper.genWriteSystemRegister("mscratch", src_reg_index)
(mscratch_val, valid) = self.readRegister("mscratch")
if not valid:
self.error("Value for register mscratch is invalid")
if mscratch_val != src_reg_val:
self.error("Value of register mscratch did not match the expected "
"value. Expected=0x%x, Actual=0x%x" %
(src_reg_val, mscratch_val))
class SystemCallSequence(Sequence):
def __init__(self, aGenThread):
super().__init__(aGenThread)
self._mAssemblyHelper = AssemblyHelperRISCV(self)
self._mDataBlockAddrRegIndex = None
self._mActionCodeRegIndex = None
def generate(self, **kwargs):
(handlers_set_name, valid) = self.getOption('handlers_set')
if valid and (handlers_set_name == 'Fast'):
self.error(
'Fast exception handlers are enabled. SystemCallSequence only supports using comprehensive exception handlers.'
)
function = kwargs.setdefault('Function', 'SwitchPrivilegeLevel')
if function == 'SwitchPrivilegeLevel':
ret_code = self._switchPrivilegeLevel(kwargs)
else:
self.error('SystemCallSequence does not support the %s function' %
function)
self._processReturnCode(ret_code, function)
## Execute a privilege level switch.
#
# @params aParams A dictionary of optional parameters.
# PrivilegeLevel: The target privilege level. Permissible values are 'U', 'S', 'M', 0, 1,
# 3 or 'Random'; defaults to 'Random'.
# TargetAddr: The address at which to resume execution after completing the privilege
# level switch. Permissible values are any 64-bit integer; defaults to a randomly
# generated valid instruction address.
# SkipAddrValidation: Specifies whether to skip validating a specified TargetAddr value.
# Permissible values are 0 or 1; defaults to 0. If SkipAddrValidation is 0, the
# TargetAddr value is checked to determine whether it is a valid instruction address.
# If it isn't, an alternative address is randomly generated. If SkipAddrValidation is
# 1, the target address value is always used as is.
# AddrChoicesModID: Specifies ID of choices modification set to be applied when generating
# the target address in the event no TargetAddr value is provided or the value
# provided is invalid. Permissible values are any valid choices modification set ID.
# InterruptMask: Value to set the xstatus.xIE field to for the target privilege level.
# Permissible values are 0, 1, 'Same', 'Flip' or 'Random'; defaults to 'Random'.
# SUM: *** Not currently supported! *** Value to set the xstatus.SUM field to for the
# target privilege level. Permissible values are 0, 1, 'Same', 'Flip' or 'Random';
# defaults to 'Random'.
# MXR: *** Not currently supported! *** Value to set the xstatus.MXR field to for the
# target privilege level. Permissible values are 0, 1, 'Same', 'Flip' or 'Random';
# defaults to 'Random'.
# MPRV: *** Not currently supported! *** Value to set the mstatus.MPRV field to for the
# target privilege level. Permissible values are 0, 1, 'Same', 'Flip' or 'Random';
# defaults to 'Random'. As this field is only relevant to M mode, it is ignored if the
# target privilege level is not M.
def _switchPrivilegeLevel(self, aParams):
except_request_results = self.exceptionRequest('SystemCall', aParams)
ret_code = except_request_results['RetCode']
if ret_code != 0:
return ret_code
self._assignRegisters(except_request_results['DataBlockAddrRegIndex'],
except_request_results['ActionCodeRegIndex'])
load_gpr64_seq = LoadGPR64(self.genThread)
load_gpr64_seq.load(self._mDataBlockAddrRegIndex,
except_request_results['DataBlockAddr'])
self._genPrivilegeLevelSwitchInstructions(
except_request_results['InstrSeqCode'],
except_request_results['PrivilegeLevel'],
except_request_results['TargetAddr'],
except_request_results['IntermediateRetAddr'])
self._unassignRegisters()
self.genSequence('UpdatePeState',
{'RecordId': except_request_results['RecordId']})
self.updateVm()
return ret_code
## Output appropriate messages based on the return code. Fail if the return code is not 0 and
# NoSkip is specified.
#
# @param aRetCode The return code from the system call operation.
# @param aFunction The operation performed by the system call.
def _processReturnCode(self, aRetCode, aFunction):
if aRetCode == 0:
self.notice('SystemCallSequence request %s processed succesfully' %
aFunction)
else:
self.notice(
'SystemCallSequence request %s could not be processed successfully; return code %d'
% (aFunction, aRetCode))
(no_skip, valid) = self.genThread.getOption('NoSkip')
if valid and (no_skip == 1) and (aRetCode != 0):
self.error(
'Unable to process SystemCallSequence request and NoSkip option was specified'
)
## Generate the instructions required to execute the privilege level switch.
#
# @param aInstrSeqCode A value indicating the instructions that need to be generated.
# @param aTargetPrivLevel The target privilege level.
# @param aTargetAddr The address at which to resume execution after completing the privilege
# level switch.
# @param aIntermediateRetAddr The return address for the first ECALL of a 2 ECALL sequence
def _genPrivilegeLevelSwitchInstructions(self, aInstrSeqCode,
aTargetPrivLevel, aTargetAddr,
aIntermediateRetAddr):
if aInstrSeqCode == 0:
# Do nothing
pass
elif aInstrSeqCode == 1:
# Generate 1 ECALL instruction
action_code = 2 # Load From Data Block
self._mAssemblyHelper.genMoveImmediate(self._mActionCodeRegIndex,
action_code)
self._genEcall()
elif aInstrSeqCode == 2:
# Generate xRET instruction
self._genXRet(aTargetPrivLevel, aTargetAddr)
elif aInstrSeqCode == 3:
# Generate 2 ECALL instructions
action_code = 1 # Return to S Mode
self._mAssemblyHelper.genMoveImmediate(self._mActionCodeRegIndex,
action_code)
self._genEcall()
self.setPEstate('PrivilegeLevel', 1)
self.setPEstate('PC', aIntermediateRetAddr)
# For a 2 ECALL sequence, the data block contains a return address for the first ECALL
# as the first entry; after the first ECALL, we increment the data block address pointer
# to allow loading the data block as usual in the second ECALL
self._mAssemblyHelper.genAddImmediate(self._mDataBlockAddrRegIndex,
8)
action_code = 2 # Load From Data Block
self._mAssemblyHelper.genMoveImmediate(self._mActionCodeRegIndex,
action_code)
self._genEcall()
else:
self.error('Unexpected InstrSeqCode value %d' % aInstrSeqCode)
## Assign registers to be used for executing the privilege level switch so that they can be
# referenced later.
#
# @param aDataBlockRegIndex The index of the register used for storing the data block address.
# @param aActionCodeRegIndex The index of the register used for storing the action code.
def _assignRegisters(self, aDataBlockRegIndex, aActionCodeRegIndex):
self._mDataBlockAddrRegIndex = aDataBlockRegIndex
self._mActionCodeRegIndex = aActionCodeRegIndex
## Clear register assignments.
def _unassignRegisters(self):
self._mActionCodeRegIndex = None
self._mDataBlockAddrRegIndex = None
## Generate an ECALL instruction.
def _genEcall(self):
self.genInstruction('ECALL##RISCV')
## Generate an xRET instruction.
#
# @param aTargetPrivLevel The target privilege level.
# @param aTargetAddr The address at which to resume execution after completing the privilege
# level switch.
def _genXRet(self, aTargetPrivLevel, aTargetAddr):
priv_level = self.getPEstate('PrivilegeLevel')
if priv_level == 1:
priv_level_prefix = 'S'
elif priv_level == 3:
priv_level_prefix = 'M'
else:
self.error(
'Unexpected request to execute xRET instruction to transition from privilege level %s to privilege level %s'
% (priv_level, aTargetPrivLevel))
# The action code register is used as a scratch register here to reduce the number of
# required registers
self.genInstruction(
'LD##RISCV', {
'rd': self._mActionCodeRegIndex,
'rs1': self._mDataBlockAddrRegIndex,
'simm12': 0,
'NoRestriction': 1
})
self._mAssemblyHelper.genWriteSystemRegister(
('%sstatus' % priv_level_prefix.lower()),
self._mActionCodeRegIndex)
self.genInstruction(
'LD##RISCV', {
'rd': self._mActionCodeRegIndex,
'rs1': self._mDataBlockAddrRegIndex,
'simm12': 8,
'NoRestriction': 1
})
self._mAssemblyHelper.genWriteSystemRegister(
('%sepc' % priv_level_prefix.lower()), self._mActionCodeRegIndex)
self.genInstruction(
'LD##RISCV', {
'rd': self._mActionCodeRegIndex,
'rs1': self._mDataBlockAddrRegIndex,
'simm12': 16,
'NoRestriction': 1
})
self._mAssemblyHelper.genWriteSystemRegister('satp',
self._mActionCodeRegIndex)
self.genInstruction(
'LD##RISCV', {
'rd': self._mActionCodeRegIndex,
'rs1': self._mDataBlockAddrRegIndex,
'simm12': 24,
'NoRestriction': 1
})
self.genInstruction(
'LD##RISCV', {
'rd': self._mDataBlockAddrRegIndex,
'rs1': self._mDataBlockAddrRegIndex,
'simm12': 32,
'NoRestriction': 1
})
self.genInstruction(('%sRET##RISCV' % priv_level_prefix),
{'NoRestriction': 1})