Implements stage 5

.asm-lsp.toml

@@ -0,0 +1,8 @@
+[default_config]
+version = "0.10.1"
+assembler = "gas"
+instruction_set = "riscv"
+
+[default_config.opts]
+diagnostics = true
+default_diagnostics = true

bench/addi.s

@@ -0,0 +1,18 @@
+# expected: dead0000, dead0001, fffff800, ffffffff, 00000000
+    .text
+_start:
+    lui x2, 0xdead0
+    lui x3, 0x0
+
+    # Add 0
+    addi x31, x2, 0x0
+
+    # Basic addition
+    addi x31, x2, 0x1
+
+    # Sign extension
+    addi x31, x3, -2048
+    addi x31, x3, -1
+
+    # Overflow
+    addi x31, x31, 0x1

src/main/scala/projet/ControlUnit.scala

@@ -8,32 +8,52 @@ class CUInterface extends Bundle {
     val instruction = Input(UInt(32.W))
     val reg_file_we = Output(Bool())
     val alu_opcode = Output(AluOpCode())
+    val optype = Output(OpType())
 
-    val mux_imm_alu = Output(Bool())
+    val mux_alu_imm = Output(Bool())
+    val mux_rega_pc = Output(Bool())
 }
 
-object OPCode extends ChiselEnum {
+object OpType extends ChiselEnum {
+    val U, I = Value
+}
+
+object OpCode extends ChiselEnum {
     val LUI = 0b0110111.U
     val AUIPC = 0b0010111.U
+    val ADDI = 0b0010011.U
 }
 
 class ControlUnit() extends Module {
-    import OPCode._
+    import OpCode._
 
     val io = IO(new CUInterface())
 
     io.reg_file_we := false.B
     io.alu_opcode := AluOpCode.Add
-    io.mux_imm_alu := false.B;
+    io.optype := OpType.U
+    io.mux_alu_imm := true.B;
+    io.mux_rega_pc := true.B;
     switch(io.instruction(6, 0)) {
+
+        // U instructions
         is(LUI) {
             io.reg_file_we := true.B
-            io.mux_imm_alu := false.B;
+            io.mux_alu_imm := false.B
+            io.optype := OpType.U
         }
         is(AUIPC) {
             io.alu_opcode := AluOpCode.Add 
             io.reg_file_we := true.B
-            io.mux_imm_alu := true.B;
+            io.mux_rega_pc := false.B
+            io.optype := OpType.U
+        }
+
+        // I instructions
+        is(ADDI) {
+            io.alu_opcode := AluOpCode.Add 
+            io.reg_file_we := true.B
+            io.optype := OpType.I
         }
     }
 }

src/main/scala/projet/ImmediateDecoder.scala

@@ -0,0 +1,31 @@
+package projet
+
+import chisel3._
+import chisel3.util.switch
+import chisel3.util.is
+import chisel3.util.Cat
+import chisel3.util.Fill
+
+class ImmediateDecoder extends Module {
+    import projet.OpType
+
+    val io = IO(new Bundle {
+        val op_type = Input(OpType())
+        val instruction = Input(UInt(32.W))
+        val immediate = Output(UInt(32.W))
+    })
+    io.immediate := 0.U
+
+    // Decode imm-u
+    val imm_u = Cat(io.instruction(31, 12), 0.U(12.W));
+    // Decode imm-i
+    val imm_i = Cat(Fill(20, io.instruction(31)), io.instruction(31, 20));
+    switch(io.op_type) {
+        is(OpType.U) {
+            io.immediate := imm_u
+        }
+        is(OpType.I) {
+            io.immediate := imm_i
+        }
+    }
+}

src/main/scala/projet/RegFile.scala

@@ -32,18 +32,14 @@ class RegFile(sim: Boolean = false) extends Module {
     io.rs2_data := regs(io.rs2_addr)
 
     // Simulation stuff
-    val valid = WireInit(false.B);
-    when(io.we && io.rd_addr === 31.U)
-    {
+    if (sim) {
+        io.valid_x31.get := false.B
+    }
+    io.x31 := "hDEADC0DE".U
+    when(io.we && io.rd_addr === 31.U) {
         io.x31 := io.rd_data
         if (sim) {
-          valid := true.B
+            io.valid_x31.get := true.B
         }
-    }.otherwise
-    {
-      io.x31 := regs(31)
-    }
-    if (sim) {
-      io.valid_x31.get := Delay.Delay(valid, 1, false.B)
     }
 }

src/main/scala/projet/Rv32i.scala

@@ -1,7 +1,6 @@
 package projet
 
 import chisel3._
-import chisel3.util.Cat
 
 class Rv32i(sim: Boolean = true) extends Module {
     val io = IO(new Bundle {
@@ -18,12 +17,15 @@ class Rv32i(sim: Boolean = true) extends Module {
     reg_file.io.rd_data := 0.U;
     io.x31 := reg_file.io.x31
     if (sim) {
-        io.valid_x31.get := reg_file.io.valid_x31.get
+        io.valid_x31.get := reg_file.io.valid_x31.get && Delay.Delay(!reset.asBool, 1, false.B)
     }
 
     val alu = Module(new Alu());
+    val immediate_decoder = Module(new ImmediateDecoder());
     val control_unit = Module(new ControlUnit());
 
+    immediate_decoder.io.instruction := instruction
+    immediate_decoder.io.op_type := control_unit.io.optype
     alu.io.opcode := control_unit.io.alu_opcode;
     reg_file.io.we := control_unit.io.reg_file_we
 
@@ -49,15 +51,18 @@ class Rv32i(sim: Boolean = true) extends Module {
     val rd = instruction(11, 7)
     reg_file.io.rd_addr := rd
 
-    // Decode imm-u
-    val imm_u = Cat(instruction(31, 12), 0.U(12.W));
-
     // EXECUTE
 
-    alu.io.a := execute_pc;
-    alu.io.b := imm_u;
+    val imm = immediate_decoder.io.immediate
 
-    reg_file.io.rd_data := Mux(control_unit.io.mux_imm_alu, alu.io.out, imm_u);
+    alu.io.a := Mux(
+        control_unit.io.mux_rega_pc,
+        reg_file.io.rs1_data,
+        execute_pc
+    );
+    alu.io.b := imm;
+
+    reg_file.io.rd_data := Mux(control_unit.io.mux_alu_imm, alu.io.out, imm);
 
     io.dbus.addr := 0.U;
     io.dbus.wdata := 0.U;