save progress before switching to new bus architecture

hs/Exceptions.hs

@@ -1,7 +1,11 @@
 {-# LANGUAGE DataKinds #-}
 {-# LANGUAGE NumericUnderscores #-}
 
-module Exceptions() where
+module Exceptions(
+    Exception(..),
+    exceptionCode,
+    isSynchronousException
+    ) where
 
 import Clash.Prelude
 
@@ -32,3 +36,56 @@ data Exception =
     | SoftwareCheck
     | HardwareError
     deriving (Generic, Show, Eq, NFDataX)
+
+exceptionCode :: Exception -> Unsigned 6
+exceptionCode SupervisorSoftwareInterrupt   = 1
+exceptionCode MachineSoftwareInterrupt      = 3
+exceptionCode SupervisorTimerInterrupt      = 5
+exceptionCode MachineTimerInterrupt         = 7
+exceptionCode SupervisorExternalInterrupt   = 9
+exceptionCode MachineExternalInterrupt      = 11
+exceptionCode CounterOverflowInterrupt      = 13
+exceptionCode InstructionAddressMisaligned  = 0
+exceptionCode InstructionAccessFault        = 1
+exceptionCode IllegalInstruction            = 2
+exceptionCode Breakpoint                    = 3
+exceptionCode LoadAddressMisaligned         = 4
+exceptionCode LoadAccessFault               = 5
+exceptionCode StoreAMOAddressMisaligned     = 6
+exceptionCode StoreAMOAccessFault           = 7
+exceptionCode EnvironmentCallFromUMode      = 8
+exceptionCode EnvironmentCallFromSMode      = 9
+exceptionCode EnvironmentCallFromMMode      = 11
+exceptionCode InstructionPageFault          = 12
+exceptionCode LoadPageFault                 = 13
+exceptionCode StoreAMOPageFault             = 15
+exceptionCode DoubleTrap                    = 16
+exceptionCode SoftwareCheck                 = 18
+exceptionCode HardwareError                 = 19
+
+isSynchronousException :: Exception -> Bool
+isSynchronousException SupervisorSoftwareInterrupt  = False
+isSynchronousException MachineSoftwareInterrupt     = False
+isSynchronousException SupervisorTimerInterrupt     = False
+isSynchronousException MachineTimerInterrupt        = False
+isSynchronousException SupervisorExternalInterrupt  = False
+isSynchronousException MachineExternalInterrupt     = False
+isSynchronousException CounterOverflowInterrupt     = False
+isSynchronousException InstructionAddressMisaligned = True
+isSynchronousException InstructionAccessFault       = True
+isSynchronousException IllegalInstruction           = True
+isSynchronousException Breakpoint                   = True
+isSynchronousException LoadAddressMisaligned        = True
+isSynchronousException LoadAccessFault              = True
+isSynchronousException StoreAMOAddressMisaligned    = True
+isSynchronousException StoreAMOAccessFault          = True
+isSynchronousException EnvironmentCallFromUMode     = True
+isSynchronousException EnvironmentCallFromSMode     = True
+isSynchronousException EnvironmentCallFromMMode     = True
+isSynchronousException InstructionPageFault         = True
+isSynchronousException LoadPageFault                = True
+isSynchronousException Reserved                     = True
+isSynchronousException StoreAMOPageFault            = True
+isSynchronousException DoubleTrap                   = True
+isSynchronousException SoftwareCheck                = True
+isSynchronousException HardwareError                = True