From 51327e00b5867ac7ff74cee22b725f119d3a8cc0 Mon Sep 17 00:00:00 2001
From: Stafford Horne <shorne@gmail.com>
Date: Sat, 19 Dec 2020 23:51:32 +0900
Subject: [PATCH] mor1kx: Enable rotate, sign extend under linux, new fpu
 extension

My thought is that if we are running linux the FPGA should be able to
handle these extra instruction's footprint.  Also, since we are running
on linux there may be any kind of software running on the CPU, so allow
handling these instructions.

FPU is added bia a new +fpu extension.

But really, I am running GLIBC tests and they run faster with this
enabled.
---
 litex/soc/cores/cpu/mor1kx/core.py | 18 +++++++++++++++---
 1 file changed, 15 insertions(+), 3 deletions(-)

diff --git a/litex/soc/cores/cpu/mor1kx/core.py b/litex/soc/cores/cpu/mor1kx/core.py
index 95b2801c3..fd663d607 100644
--- a/litex/soc/cores/cpu/mor1kx/core.py
+++ b/litex/soc/cores/cpu/mor1kx/core.py
@@ -15,7 +15,7 @@ from litex import get_data_mod
 from litex.soc.interconnect import wishbone
 from litex.soc.cores.cpu import CPU
 
-CPU_VARIANTS = ["standard", "linux"]
+CPU_VARIANTS = ["standard", "standard+fpu", "linux", "linux+fpu"]
 
 
 class MOR1KX(CPU):
@@ -51,6 +51,11 @@ class MOR1KX(CPU):
         flags =  "-mhard-mul "
         flags += "-mhard-div "
         flags += "-D__mor1kx__ "
+
+        if "linux" in self.variant:
+            flags += "-mror "
+            flags += "-msext "
+
         return flags
 
     @property
@@ -77,7 +82,7 @@ class MOR1KX(CPU):
         self.memory_buses = []
 
 
-        if variant == "linux":
+        if "linux" in variant:
             self.mem_map = self.mem_map_linux
 
         # # #
@@ -107,7 +112,12 @@ class MOR1KX(CPU):
             p_DBUS_WB_TYPE              = "B3_REGISTERED_FEEDBACK",
         )
 
-        if variant == "linux":
+        if "fpu" in variant:
+            cpu_args.update(
+                p_FEATURE_FPU = "ENABLED",
+            )
+
+        if "linux" in variant:
             cpu_args.update(
                 # Linux needs the memory management units.
                 p_FEATURE_IMMU  = "ENABLED",
@@ -115,6 +125,8 @@ class MOR1KX(CPU):
                 # FIXME: Currently we need the or1k timer when we should be
                 # using the litex timer.
                 p_FEATURE_TIMER = "ENABLED",
+                p_FEATURE_ROR = "ENABLED",
+                p_FEATURE_EXT = "ENABLED",
             )
             # FIXME: Check if these are needed?
             use_defaults = (