From 639f91b19263e09b64bfdee4d42e54f96a2c6aaf Mon Sep 17 00:00:00 2001
From: Anton Lydike <me@antonlydike.de>
Date: Tue, 8 Jun 2021 11:31:58 +0200
Subject: [PATCH] [decoder] removed sign extension for CSR type instructions

---
 riscemu/decoder/formats.py | 6 +++++-
 1 file changed, 5 insertions(+), 1 deletion(-)

diff --git a/riscemu/decoder/formats.py b/riscemu/decoder/formats.py
index 296e6ca..9d3e544 100644
--- a/riscemu/decoder/formats.py
+++ b/riscemu/decoder/formats.py
@@ -98,6 +98,10 @@ def decode_i_shamt(ins: int) -> List[int]:
     return decode_i(ins)
 
 
+def decode_i_unsigned(ins: int) -> List[int]:
+    return [rd(ins), rs1(ins), imm110(ins)]
+
+
 INSTRUCTION_ARGS_DECODER: Dict[int, Callable[[int], List[int]]] = {
     0x00: decode_i,
     0x04: decode_i_shamt,
@@ -108,5 +112,5 @@ INSTRUCTION_ARGS_DECODER: Dict[int, Callable[[int], List[int]]] = {
     0x18: decode_b,
     0x19: decode_i,
     0x1b: decode_j,
-    0x1c: decode_i
+    0x1c: decode_i_unsigned
 }