From 63a73d3f7154b588af41766f41f347d79941474c Mon Sep 17 00:00:00 2001
From: Yehowshua Immanuel <yehowshua@joyofhardware.com>
Date: Fri, 7 Mar 2025 21:41:46 -0500
Subject: [PATCH] now fetching from ram correctly as ram is 32 bit word not
 byte indexed

---
 README.md        | 5 +++++
 hs/Bus.hs        | 4 +++-
 hs/Simulation.hs | 1 +
 3 files changed, 9 insertions(+), 1 deletion(-)

diff --git a/README.md b/README.md
index 8a1d475..9131f8b 100644
--- a/README.md
+++ b/README.md
@@ -25,6 +25,11 @@ essence forms the context of our micro-op machinery.
 
 Change instructions to support Nix
 
+## Disassembling
+```
+riscv64-unknown-elf-objdump -D -b binary -m riscv:rv64 ./rv_tests/hello_world/hello.bin > hello.asm
+```
+
 
 # TODO
  - [ ] fetch should invoke mem read function
diff --git a/hs/Bus.hs b/hs/Bus.hs
index b74abab..efb254a 100644
--- a/hs/Bus.hs
+++ b/hs/Bus.hs
@@ -56,7 +56,7 @@ read :: ReadRequest -> Peripherals -> IO ReadResponse
 read (Request addr size) peripherals
   | not (alignCheck addr size) = return |> Left UnAligned
   | (addr >= ramStart) && (addr <= ramEnd) =
-      return |> Right |> Peripherals.Ram.read size ramAddr (ram peripherals)
+      return |> Right |> Peripherals.Ram.read size ramWordAddr (ram peripherals)
   | (addr >= uartStart) && (addr <= uartEnd) =
       fmap Right (Peripherals.Uart.read size uartAddr)
   | otherwise = return |> Left UnMapped
@@ -64,6 +64,8 @@ read (Request addr size) peripherals
       ramAddrNoOffset = addr - ramStart
       ramAddr :: RamAddr
       ramAddr = resize ramAddrNoOffset
+      ramWordAddr :: RamAddr
+      ramWordAddr = resize |> ramAddrNoOffset `shiftR` 2
 
       uartAddrNoOffset = addr - uartStart
       uartAddr :: UartAddr
diff --git a/hs/Simulation.hs b/hs/Simulation.hs
index d3dbd65..c6cacbe 100644
--- a/hs/Simulation.hs
+++ b/hs/Simulation.hs
@@ -46,6 +46,7 @@ simulationLoop n machine = do
   fetchResult <- fetchInstruction machinePeripherals currPc
   let decodeResult = decode fetchResult
   putStrLn |> show decodeResult P.++ debugInsn fetchResult
+  putStrLn $ "PC: " P.++ show currPc
   let pc' = currPc + 4
       cpu' = (cpu machine) { pc = pc' }
       machine' = machine { cpu = cpu' }