From d003c568cfc71ccdbe86c00ba29964410d288f10 Mon Sep 17 00:00:00 2001
From: Luke Kenneth Casson Leighton <lkcl@lkcl.net>
Date: Sun, 25 Nov 2018 11:07:19 +0000
Subject: [PATCH] add mstatus, mip and vendor/arch/mimpl

---
 cpu.py | 107 ++++++++++++++++++++++++---------------------------------
 1 file changed, 45 insertions(+), 62 deletions(-)

diff --git a/cpu.py b/cpu.py
index 4fbeafe..98ea036 100644
--- a/cpu.py
+++ b/cpu.py
@@ -80,7 +80,7 @@ class MStatus:
         self.uie = Signal(name="mstatus_uie")
 
         for n in dir(self):
-            if n in ['mpp', 'comb', 'sync'] or n.startswith("_"):
+            if n in ['make', 'mpp', 'comb', 'sync'] or n.startswith("_"):
                 continue
             self.comb += getattr(self, n).eq(0x0)
         self.comb += self.mpp.eq(0b11)
@@ -88,6 +88,18 @@ class MStatus:
         self.sync += self.mie.eq(0)
         self.sync += self.mpie.eq(0)
 
+    def make(self):
+        return Cat(
+                self.uie, self.sie, Constant(0), self.mie,
+                self.upie, self.spie, Constant(0), self.mpie,
+                self.spp, Constant(0, 2), self.mpp,
+                self.fs, self.xs, self.mprv, self._sum,
+                self.mxr, self.tvm, self.tw, self.tsr,
+                Constant(0, 8),
+                (self.xs == Constant(0b11, 2)) | (self.fs == Constant(0b11, 2))
+                )
+
+
 class MIE:
     def __init__(self, comb, sync):
         self.comb = comb
@@ -102,7 +114,7 @@ class MIE:
         self.usie = Signal(name="mie_usie")
 
         for n in dir(self):
-            if n in ['comb', 'sync'] or n.startswith("_"):
+            if n in ['make', 'comb', 'sync'] or n.startswith("_"):
                 continue
             self.comb += getattr(self, n).eq(0x0)
 
@@ -110,6 +122,25 @@ class MIE:
         self.sync += self.mtie.eq(0)
         self.sync += self.msie.eq(0)
 
+class MIP:
+    def __init__(self, comb, sync):
+        self.comb = comb
+        self.sync = sync
+        self.meip = Signal(name="mip_meip") # TODO: implement ext interrupts
+        self.seip = Signal(name="mip_seip")
+        self.ueip = Signal(name="mip_uiep")
+        self.mtip = Signal(name="mip_mtip") # TODO: implement timer interrupts
+        self.stip = Signal(name="mip_stip")
+        self.msip = Signal(name="mip_stip")
+        self.utip = Signal(name="mip_utip")
+        self.ssip = Signal(name="mip_ssip")
+        self.usip = Signal(name="mip_usip")
+
+        for n in dir(self):
+            if n in ['comb', 'sync'] or n.startswith("_"):
+                continue
+            self.comb += getattr(self, n).eq(0x0)
+
 
 class M:
     def __init__(self, comb, sync):
@@ -404,8 +435,18 @@ class CPU(Module):
 
         misa = Misa(self.comb, self.sync)
 
-        #self.sync += If(self.reset, self.reset_to_initial(m, mstatus, mie,
-        #                                                  registers))
+        mvendorid = Signal(32)
+        marchid = Signal(32)
+        mimpid = Signal(32)
+        mhartid = Signal(32)
+        self.comb += mvendorid.eq(Constant(0, 32))
+        self.comb += marchid.eq(Constant(0, 32))
+        self.comb += mimpid.eq(Constant(0, 32))
+        self.comb += mhartid.eq(Constant(0, 32))
+
+        mip = MIP(self.comb, self.sync)
+
+        csr_op_is_valid = Signal()
 
 if __name__ == "__main__":
     example = CPU()
@@ -422,64 +463,6 @@ if __name__ == "__main__":
 
 """
 
-    parameter mvendorid = 32'b0;
-    parameter marchid = 32'b0;
-    parameter mimpid = 32'b0;
-    parameter mhartid = 32'b0;
-
-    function [31:0] make_mstatus(input mstatus_tsr,
-        input mstatus_tw,
-        input mstatus_tvm,
-        input mstatus_mxr,
-        input mstatus_sum,
-        input mstatus_mprv,
-        input [1:0] mstatus_xs,
-        input [1:0] mstatus_fs,
-        input [1:0] mstatus_mpp,
-        input mstatus_spp,
-        input mstatus_mpie,
-        input mstatus_spie,
-        input mstatus_upie,
-        input mstatus_mie,
-        input mstatus_sie,
-        input mstatus_uie);
-    begin
-        make_mstatus = {(mstatus_xs == 2'b11) | (mstatus_fs == 2'b11),
-            8'b0,
-            mstatus_tsr,
-            mstatus_tw,
-            mstatus_tvm,
-            mstatus_mxr,
-            mstatus_sum,
-            mstatus_mprv,
-            mstatus_xs,
-            mstatus_fs,
-            mstatus_mpp,
-            2'b0,
-            mstatus_spp,
-            mstatus_mpie,
-            1'b0,
-            mstatus_spie,
-            mstatus_upie,
-            mstatus_mie,
-            1'b0,
-            mstatus_sie,
-            mstatus_uie};
-    end
-    endfunction
-
-    wire mip_meip = 0; // TODO: implement external interrupts
-    parameter mip_seip = 0;
-    parameter mip_ueip = 0;
-    wire mip_mtip = 0; // TODO: implement timer interrupts
-    parameter mip_stip = 0;
-    parameter mip_utip = 0;
-    parameter mip_msip = 0;
-    parameter mip_ssip = 0;
-    parameter mip_usip = 0;
-
-    wire csr_op_is_valid;
-
     function `fetch_action get_fetch_action(
         input `fetch_output_state fetch_output_state,
         input `decode_action decode_action,
-- 
2.30.2