more progress on UART read

hs/Peripherals/Ram.hs

@@ -21,10 +21,7 @@ import qualified Clash.Sized.Vector as Vec
 import Types(Addr,
              Byte, HalfWord, FullWord, DoubleWord, QuadWord)
 import BusTypes(
-    BusError(..),
     TransactionSize(..),
-    Request(..),
-    BusResponse(..),
     BusVal(..),
     ReadResponse(..),
     WriteResponse(..)
@@ -129,6 +126,3 @@ populateVectorFromInt32 ls v = Vec.fromList adjustedLs
     adjustedLs = fromIntegral <$> adjustLength vecLen ls
     adjustLength :: Int -> [Int32] -> [Int32]
     adjustLength n xs = P.take n (xs P.++ P.repeat 0)
-
-
-

hs/Peripherals/Setup.hs

@@ -3,7 +3,7 @@ module Peripherals.Setup (
   ) where
 
 import Prelude
-import Peripherals.UartCFFI(initTerminal, restoreTerminal)
+import Peripherals.UartCFFI(initTerminal)
 import Peripherals.Ram (initRamFromFile, Ram)
 import Control.Exception (try)
 import System.IO.Error (ioeGetErrorString)

hs/Peripherals/Uart.hs

@@ -0,0 +1,61 @@
+module Peripherals.Uart (read) where
+
+import Clash.Prelude hiding (read)
+import Types (Byte)
+import Data.Char (ord)
+
+import Peripherals.UartCFFI (
+    initTerminal,
+    restoreTerminal,
+    getCharFromTerminal,
+    writeCharToTerminal,
+    isCharAvailable,
+    setupSigintHandler,
+    wasCtrlCReceived
+  )
+
+import BusTypes (
+    TransactionSize(..),
+    BusVal(..),
+    ReadResponse(..),
+    WriteResponse(..)
+  )
+
+-- based on a 16550 UART which has an address space of 8 bytes
+type UartAddr = Unsigned 3
+
+-- Receiver Buffer Register address (commonly 0x0 for 16550 UART)
+rbrAddr :: UartAddr
+rbrAddr = 0x0
+
+-- Line Status Register address
+lsrAddr :: UartAddr
+lsrAddr = 0x5
+
+-- Helper function to convert Byte to BusVal based on TransactionSize
+busValFromByte :: TransactionSize -> Byte -> BusVal
+busValFromByte size val = case size of
+  SizeByte       -> BusByte val
+  SizeHalfWord   -> BusHalfWord (resize val)
+  SizeFullWord   -> BusFullWord (resize val)
+  SizeDoubleWord -> BusDoubleWord (resize val)
+  SizeQuadWord   -> BusQuadWord (resize val)
+
+-- Reads a character from the terminal (RBR equivalent)
+buildRBR :: IO Byte
+buildRBR = do
+  c <- getCharFromTerminal
+  return $ fromIntegral (ord c)  -- Convert Char to Byte
+
+-- Reads the Line Status Register (LSR) to check character availability
+buildLSR :: IO Byte
+buildLSR = do
+  char_available <- isCharAvailable
+  return $ fromIntegral char_available
+
+-- Updated 'read' function to handle RBR and LSR reads
+read :: TransactionSize -> UartAddr -> IO BusVal
+read size addr
+  | addr == rbrAddr = busValFromByte size <$> buildRBR
+  | addr == lsrAddr = busValFromByte size <$> buildLSR
+  | otherwise       = return $ busValFromByte size 0x00