From 8c1be04af62a333cff54aa5f349e8bb9e203f267 Mon Sep 17 00:00:00 2001
From: Gabe Black <gblack@eecs.umich.edu>
Date: Wed, 2 Jun 2010 12:58:08 -0500
Subject: [PATCH] ARM: Decode the thumb versions of the mcr and mrc
 instructions.

---
 src/arch/arm/isa/decoder/thumb.isa | 18 ++++++++++++------
 src/arch/arm/isa/formats/misc.isa  | 27 +++++++++++++++++++++++++++
 2 files changed, 39 insertions(+), 6 deletions(-)

diff --git a/src/arch/arm/isa/decoder/thumb.isa b/src/arch/arm/isa/decoder/thumb.isa
index da8248683..e8e2d5919 100644
--- a/src/arch/arm/isa/decoder/thumb.isa
+++ b/src/arch/arm/isa/decoder/thumb.isa
@@ -90,9 +90,12 @@
                     }
                     0x1: decode LTCOPROC {
                         0xa, 0xb: WarnUnimpl::Core_to_extension_transfer();
-                        default: decode HTOPCODE_4 {
-                            0x0: WarnUnimpl::mcr(); // mcr2
-                            0x1: WarnUnimpl::mrc(); // mrc2
+                        default: decode CPNUM {
+                            15: McrMrc15::mcrMrc15();
+                            default: decode HTOPCODE_4 {
+                                0x0: WarnUnimpl::mcr();
+                                0x1: WarnUnimpl::mrc();
+                            }
                         }
                     }
                 }
@@ -155,9 +158,12 @@
                     }
                     0x1: decode LTCOPROC {
                         0xa, 0xb: WarnUnimpl::Core_to_extension_transfer();
-                        default: decode HTOPCODE_4 {
-                            0x0: WarnUnimpl::mcr(); // mcr2
-                            0x1: WarnUnimpl::mrc(); // mrc2
+                        default: decode CPNUM {
+                            15: McrMrc15::mcr2Mrc215();
+                            default: decode HTOPCODE_4 {
+                                0x0: WarnUnimpl::mcr2();
+                                0x1: WarnUnimpl::mrc2();
+                            }
                         }
                     }
                 }
diff --git a/src/arch/arm/isa/formats/misc.isa b/src/arch/arm/isa/formats/misc.isa
index 36bccbba4..897ecf3e3 100644
--- a/src/arch/arm/isa/formats/misc.isa
+++ b/src/arch/arm/isa/formats/misc.isa
@@ -77,3 +77,30 @@ def format ArmMsrMrs() {{
     }
     '''
 }};
+
+def format McrMrc15() {{
+    decode_block = '''
+    {
+        const uint32_t opc1 = bits(machInst, 23, 21);
+        const uint32_t crn = bits(machInst, 19, 16);
+        const uint32_t opc2 = bits(machInst, 7, 5);
+        const uint32_t crm = bits(machInst, 3, 0);
+        const MiscRegIndex miscReg = decodeCP15Reg(crn, opc1, crm, opc2);
+        const IntRegIndex rt = (IntRegIndex)(uint32_t)bits(machInst, 15, 12);
+
+        const bool isRead = bits(machInst, 20);
+
+        if (miscReg == MISCREG_NOP) {
+            return new NopInst(machInst);
+        } else if (miscReg == NUM_MISCREGS) {
+            return new Unknown(machInst);
+        } else {
+            if (isRead) {
+                return new Mrc15(machInst, rt, (IntRegIndex)miscReg);
+            } else {
+                return new Mcr15(machInst, (IntRegIndex)miscReg, rt);
+            }
+        }
+    }
+    '''
+}};