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added basic decoding

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Yehowshua Immanuel 2025-02-19 01:21:02 -05:00
parent ef58d5b07e
commit 32932f4816
7 changed files with 289 additions and 61 deletions
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52
hs/Decode/Opcodes.hs
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@ -1,52 +0,0 @@
{-# LANGUAGE DataKinds #-}
{-# LANGUAGE NumericUnderscores #-}
module Decode.Opcodes(Opcode(..)) where
import Clash.Prelude
import Data.Functor.Contravariant (Op)
type FUNCT7 = Unsigned 7
type RS2 = Unsigned 5
type RS1 = Unsigned 5
type FUNCT3 = Unsigned 3
type RD = Unsigned 5
type OPCODE = Unsigned 7
type IMM12 = Unsigned 12
type IMM13 = Unsigned 13
type IMM20 = Unsigned 20
type IMM21 = Unsigned 21
data RTypeFields = RTypeFields OPCODE RD FUNCT3 RS1 RS2 FUNCT7
data ITypeFields = ITypeFields OPCODE RD FUNCT3 RS1 IMM12
data STypeFields = STypeFields OPCODE FUNCT3 RS1 RS2 IMM12
data BTypeFields = BTypeFields OPCODE FUNCT3 RS1 RS2 IMM13
data UTypeFields = UTypeFields OPCODE RD IMM20
data JTypeFields = JTypeFields OPCODE RD IMM21
data Opcode
= ADD RTypeFields
| SUB RTypeFields
| XOR RTypeFields
| OR RTypeFields
| AND RTypeFields
| SLL RTypeFields
| SRL RTypeFields
| SRA RTypeFields
| SLT RTypeFields
| SLTU RTypeFields
| ADDRI ITypeFields
| XORI ITypeFields
| ORI ITypeFields
| ANDI ITypeFields
| SLLI ITypeFields
| SRLI ITypeFields
| SRAI ITypeFields
| SLTI ITypeFields
| SLTIU ITypeFields
| LB ITypeFields
| LH ITypeFields
| LW ITypeFields
| LBU ITypeFields
| LHU ITypeFields

6
hs/Fetch.hs
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@ -4,13 +4,13 @@
module Fetch(fetchInstruction) where
import Clash.Prelude
import Types(Mem, Addr, FullWord)
import Types(Mem, Addr, Insn)
import Util(endianSwapWord)
data Insn = Instruction FullWord
data FetchResult = Instruction Insn
| Misaligned Addr
fetchInstruction :: KnownNat n => Mem n -> Addr -> Insn
fetchInstruction :: KnownNat n => Mem n -> Addr -> FetchResult
fetchInstruction mem addr =
let
isWordAligned = addr .&. 3 == 0

192
hs/Isa/Decode.hs Normal file
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@ -0,0 +1,192 @@
{-# LANGUAGE DataKinds #-}
{-# LANGUAGE NumericUnderscores #-}
module Isa.Decode(decode) where
import Isa.Forms(
FUNCT7, RS2, RS1, FUNCT3, RD, OPCODE,
IMM12, IMM13, IMM20, IMM21,
RTypeFields(..), ITypeFields(..), STypeFields(..),
BTypeFields(..), UTypeFields(..), JTypeFields(..),
Opcode(..)
)
import Clash.Prelude
import Data.Functor.Contravariant (Op)
import Types(Mem, Addr, Insn)
import Distribution.Backpack.FullUnitId (FullDb)
getOpcode :: Insn -> Unsigned 7
getOpcode instr = bitCoerce $ slice d6 d0 (pack instr)
getImm12 :: Insn -> Unsigned 12
getImm12 instr = bitCoerce $ slice d31 d20 (pack instr)
getImm12SType :: Insn -> Unsigned 12
getImm12SType instr = bitCoerce $ immediateUpper ++# immediateLower
where
immediateUpper = (slice d31 d25 (pack instr))
immediateLower = (slice d11 d7 (pack instr))
getImm20UType :: Insn -> Unsigned 20
getImm20UType instr = bitCoerce $ slice d31 d12 (pack instr)
getImm13BType :: Insn -> Unsigned 13
getImm13BType instr = bitCoerce $ imm12 ++# imm10_5 ++# imm4_1 ++# imm11 ++# zero
where
imm12 = slice d31 d31 (pack instr) -- imm[12]
imm10_5 = slice d30 d25 (pack instr) -- imm[10:5]
imm4_1 = slice d11 d8 (pack instr) -- imm[4:1]
imm11 = slice d7 d7 (pack instr) -- imm[11]
zero = 0 :: BitVector 1 -- LSB always zero for B-type
getFunct3 :: Insn -> Unsigned 3
getFunct3 instr = bitCoerce $ slice d14 d12 (pack instr)
getFunct7 :: Insn -> Unsigned 7
getFunct7 instr = bitCoerce $ slice d31 d25 (pack instr)
getRd :: Insn -> Unsigned 5
getRd instr = bitCoerce $ slice d11 d7 (pack instr)
getRs2 :: Insn -> Unsigned 5
getRs2 instr = bitCoerce $ slice d24 d20 (pack instr)
getRs1 :: Insn -> Unsigned 5
getRs1 instr = bitCoerce $ slice d19 d15 (pack instr)
decodeRType :: Insn -> Opcode
decodeRType insn =
case funct3 of
0x00 -> ADD (RTypeFields opcode rd funct3 rs1 rs2 funct7)
0x00 -> SUB (RTypeFields opcode rd funct3 rs1 rs2 funct7)
0x04 -> XOR (RTypeFields opcode rd funct3 rs1 rs2 funct7)
0x06 -> OR (RTypeFields opcode rd funct3 rs1 rs2 funct7)
0x07 -> AND (RTypeFields opcode rd funct3 rs1 rs2 funct7)
0x01 -> SLL (RTypeFields opcode rd funct3 rs1 rs2 funct7)
0x05 -> SRL (RTypeFields opcode rd funct3 rs1 rs2 funct7)
0x05 -> SRA (RTypeFields opcode rd funct3 rs1 rs2 funct7)
0x02 -> SLT (RTypeFields opcode rd funct3 rs1 rs2 funct7)
0x03 -> SLTU (RTypeFields opcode rd funct3 rs1 rs2 funct7)
_ -> Unimplemented
where
opcode = getOpcode insn
rd = getRd insn
funct3 = getFunct3 insn
rs1 = getRs1 insn
rs2 = getRs2 insn
funct7 = getFunct7 insn
decodeIType :: Insn -> Opcode
decodeIType insn = case opcode of
0b0010011 -> case funct3 of
0x0 -> ADDI (ITypeFields opcode rd funct3 rs1 imm)
0x4 -> XORI (ITypeFields opcode rd funct3 rs1 imm)
0x6 -> ORI (ITypeFields opcode rd funct3 rs1 imm)
0x7 -> ANDI (ITypeFields opcode rd funct3 rs1 imm)
0x1 -> if slice d31 d25 (pack insn) == 0
then SLLI (ITypeFields opcode rd funct3 rs1 imm)
else Unimplemented
0x5 -> case slice d31 d25 (pack insn) of -- Distinguish SRLI and SRAI
0x00 -> SRLI (ITypeFields opcode rd funct3 rs1 imm)
0x20 -> SRAI (ITypeFields opcode rd funct3 rs1 imm)
_ -> Unimplemented
0x2 -> SLTI (ITypeFields opcode rd funct3 rs1 imm)
0x3 -> SLTIU (ITypeFields opcode rd funct3 rs1 imm)
_ -> Unimplemented
0b0000011 -> case funct3 of
0x0 -> LB (ITypeFields opcode rd funct3 rs1 imm)
0x1 -> LH (ITypeFields opcode rd funct3 rs1 imm)
0x2 -> LW (ITypeFields opcode rd funct3 rs1 imm)
0x4 -> LBU (ITypeFields opcode rd funct3 rs1 imm)
0x5 -> LHU (ITypeFields opcode rd funct3 rs1 imm)
_ -> Unimplemented
0b1100111 -> case funct3 of
0x0 -> JALR (ITypeFields opcode rd funct3 rs1 imm)
_ -> Unimplemented
0b1110011 -> case imm of
0x000 -> ECALL (ITypeFields opcode rd funct3 rs1 imm)
0x001 -> EBREAK (ITypeFields opcode rd funct3 rs1 imm)
_ -> Unimplemented
_ -> Unimplemented
where
opcode = getOpcode insn
rd = getRd insn
funct3 = getFunct3 insn
rs1 = getRs1 insn
imm = getImm12 insn
decodeSType :: Insn -> Opcode
decodeSType insn = case funct3 of
0x0 -> SB (STypeFields opcode funct3 rs1 rs2 imm12) -- Store Byte
0x1 -> SH (STypeFields opcode funct3 rs1 rs2 imm12) -- Store Halfword
0x2 -> SW (STypeFields opcode funct3 rs1 rs2 imm12) -- Store Word
_ -> Unimplemented
where
opcode = getOpcode insn
funct3 = getFunct3 insn
rs1 = getRs1 insn
rs2 = getRs2 insn
imm12 = getImm12SType insn
decodeBType :: Insn -> Opcode
decodeBType insn = case funct3 of
0x0 -> BEQ (BTypeFields opcode funct3 rs1 rs2 imm13) -- Branch if equal
0x1 -> BNE (BTypeFields opcode funct3 rs1 rs2 imm13) -- Branch if not equal
0x4 -> BLT (BTypeFields opcode funct3 rs1 rs2 imm13) -- Branch if less than
0x5 -> BGE (BTypeFields opcode funct3 rs1 rs2 imm13) -- Branch if greater or equal
0x6 -> BLTU (BTypeFields opcode funct3 rs1 rs2 imm13) -- Branch if less than (unsigned)
0x7 -> BGEU (BTypeFields opcode funct3 rs1 rs2 imm13) -- Branch if greater or equal (unsigned)
_ -> Unimplemented
where
opcode = getOpcode insn
funct3 = getFunct3 insn
rs1 = getRs1 insn
rs2 = getRs2 insn
imm13 = getImm13BType insn
decodeUType :: Insn -> Opcode
decodeUType insn = case opcode of
0b0110111 -> LUI (UTypeFields opcode rd imm20) -- LUI
0b0010111 -> AUIPC (UTypeFields opcode rd imm20) -- AUIPC
_ -> Unimplemented
where
opcode = getOpcode insn
rd = getRd insn
imm20 = getImm20UType insn
getImm21JType :: Insn -> Unsigned 21
getImm21JType instr = bitCoerce $ imm20 ++# imm10_1 ++# imm11 ++# imm19_12 ++# zero
where
imm20 = slice d31 d31 (pack instr) -- imm[20]
imm10_1 = slice d30 d21 (pack instr) -- imm[10:1]
imm11 = slice d20 d20 (pack instr) -- imm[11]
imm19_12 = slice d19 d12 (pack instr) -- imm[19:12]
zero = 0 :: BitVector 1 -- LSB always zero for J-type
decodeJType :: Insn -> Opcode
decodeJType insn = case getOpcode insn of
0b1101111 -> JAL (JTypeFields opcode rd imm21) -- JAL
_ -> Unimplemented
where
opcode = getOpcode insn
rd = getRd insn
imm21 = getImm21JType insn
orElse :: Opcode -> Opcode -> Opcode
orElse Unimplemented y = y
orElse x _ = x
decode :: Insn -> Opcode
decode insn =
decodeRType insn `orElse`
decodeIType insn `orElse`
decodeSType insn `orElse`
decodeBType insn `orElse`
decodeUType insn `orElse`
decodeJType insn

89
hs/Isa/Forms.hs Normal file
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@ -0,0 +1,89 @@
{-# LANGUAGE DataKinds #-}
{-# LANGUAGE NumericUnderscores #-}
module Isa.Forms(
FUNCT7, RS2, RS1, FUNCT3, RD, OPCODE,
IMM12, IMM13, IMM20, IMM21,
RTypeFields(..), ITypeFields(..), STypeFields(..),
BTypeFields(..), UTypeFields(..), JTypeFields(..),
Opcode(..)
) where
import Clash.Prelude
import Types(Mem, Addr, Insn)
type FUNCT7 = Unsigned 7
type RS2 = Unsigned 5
type RS1 = Unsigned 5
type FUNCT3 = Unsigned 3
type RD = Unsigned 5
type OPCODE = Unsigned 7
type IMM12 = Unsigned 12
type IMM13 = Unsigned 13
type IMM20 = Unsigned 20
type IMM21 = Unsigned 21
data RTypeFields = RTypeFields OPCODE RD FUNCT3 RS1 RS2 FUNCT7 deriving (Generic, Show, Eq, NFDataX)
data ITypeFields = ITypeFields OPCODE RD FUNCT3 RS1 IMM12 deriving (Generic, Show, Eq, NFDataX)
data STypeFields = STypeFields OPCODE FUNCT3 RS1 RS2 IMM12 deriving (Generic, Show, Eq, NFDataX)
data BTypeFields = BTypeFields OPCODE FUNCT3 RS1 RS2 IMM13 deriving (Generic, Show, Eq, NFDataX)
data UTypeFields = UTypeFields OPCODE RD IMM20 deriving (Generic, Show, Eq, NFDataX)
data JTypeFields = JTypeFields OPCODE RD IMM21 deriving (Generic, Show, Eq, NFDataX)
data Opcode
=
-- R-Type
ADD RTypeFields
| SUB RTypeFields
| XOR RTypeFields
| OR RTypeFields
| AND RTypeFields
| SLL RTypeFields
| SRL RTypeFields
| SRA RTypeFields
| SLT RTypeFields
| SLTU RTypeFields
-- I-Type
| ADDI ITypeFields
| XORI ITypeFields
| ORI ITypeFields
| ANDI ITypeFields
| SLLI ITypeFields
| SRLI ITypeFields
| SRAI ITypeFields
| SLTI ITypeFields
| SLTIU ITypeFields
| LB ITypeFields
| LH ITypeFields
| LW ITypeFields
| LBU ITypeFields
| LHU ITypeFields
| ECALL ITypeFields
| EBREAK ITypeFields
-- S-Type
| SB STypeFields
| SH STypeFields
| SW STypeFields
-- B-Type
| BEQ BTypeFields
| BNE BTypeFields
| BLT BTypeFields
| BGE BTypeFields
| BLTU BTypeFields
| BGEU BTypeFields
-- J-Type
| JAL JTypeFields
| JALR ITypeFields
-- U-Type
| LUI UTypeFields
| AUIPC UTypeFields
| Unimplemented
deriving (Generic, Show, Eq, NFDataX)

3
hs/Simulation.hs
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@ -47,9 +47,6 @@ machine' machine =
in
machine { cpu = cpu', mem = mem' }
machineSignal :: HiddenClockResetEnable dom => Signal dom Machine
machineSignal = register machine (machine' <$> machineSignal)
simulationLoop :: Int -> Machine -> IO [Machine]
simulationLoop 0 state = return [state]
simulationLoop n state = do

3
hs/Types.hs
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@ -1,7 +1,7 @@
{-# LANGUAGE DataKinds #-}
{-# LANGUAGE NumericUnderscores #-}
module Types(Pc, BusVal(..), Mem, FullWord, Addr) where
module Types(Pc, BusVal(..), Mem, FullWord, Insn, Addr) where
import Clash.Prelude
@ -10,6 +10,7 @@ type HalfWord = Unsigned 16
type FullWord = Unsigned 32
type DoubleWord = Unsigned 64
type QuadWord = Unsigned 128
type Insn = FullWord
data BusVal
= BusByte Byte

3
rv_formal.cabal
View file

@ -87,7 +87,8 @@ library
exposed-modules:
Simulation
other-modules:
Decode.Opcodes,
Isa.Decode,
Isa.Forms,
Peripherals.Ram,
Peripherals.UartCFFI,
Peripherals.Setup,