From 262b188790ddba8f3a9c957d4e237047d8cfb708 Mon Sep 17 00:00:00 2001
From: TomW <TomW@localhost>
Date: Sat, 23 Aug 2014 16:28:16 +0100
Subject: [PATCH] Implemented CR4 register for Winchip. Currently only Time
 Stamp Disable (TSD) has an effect. Fixed stupid bug in WRMSR - MSRs can now
 be written with values other than zero.

---
 src/808x.c             |  2 ++
 src/cpu.c              |  8 +++++++-
 src/cpu.h              |  8 ++++++++
 src/ibm.h              |  2 +-
 src/x86_ops_mov_ctrl.h | 26 ++++++++++++++++++++++++++
 src/x86_ops_msr.h      |  5 +++++
 6 files changed, 49 insertions(+), 2 deletions(-)

diff --git a/src/808x.c b/src/808x.c
index 91e4447..85ea40c 100644
--- a/src/808x.c
+++ b/src/808x.c
@@ -630,6 +630,7 @@ void resetx86()
         pc=0;
         msw=0;
         cr0=0;
+        cr4 = 0;
         eflags=0;
         cgate32=0;
         loadcs(0xFFFF);
@@ -660,6 +661,7 @@ void softresetx86()
         pc=0;
         msw=0;
         cr0=0;
+        cr4 = 0;
         eflags=0;
         cgate32=0;
         loadcs(0xFFFF);
diff --git a/src/cpu.c b/src/cpu.c
index c607a97..e0ce645 100644
--- a/src/cpu.c
+++ b/src/cpu.c
@@ -20,6 +20,10 @@ int cpu_16bitbus;
 int cpu_busspeed;
 int cpu_hasrdtsc;
 int cpu_hasMMX, cpu_hasMSR;
+int cpu_hasCR4;
+
+uint64_t cpu_CR4_mask;
+
 uint64_t tsc = 0;
 
 int timing_rr;
@@ -267,6 +271,7 @@ void cpu_set()
         cpu_hasrdtsc = 0;
         cpu_hasMMX = 0;
         cpu_hasMSR = 0;
+        cpu_hasCR4 = 0;
 
         if (cpu_iscyrix)
            io_sethandler(0x0022, 0x0002, cyrix_read, NULL, NULL, cyrix_write, NULL, NULL, NULL);
@@ -413,6 +418,8 @@ void cpu_set()
                 cpu_hasrdtsc = 1;
                 msr.fcr = (1 << 8) | (1 << 9) | (1 << 12) |  (1 << 16) | (1 << 19) | (1 << 21);
                 cpu_hasMMX = cpu_hasMSR = 1;
+                cpu_hasCR4 = 1;
+                cpu_CR4_mask = CR4_TSD | CR4_DE | CR4_MCE | CR4_PCE;
                 break;
                 
                 default:
@@ -549,7 +556,6 @@ void cpu_WRMSR()
         switch (models[model].cpu[cpu_manufacturer].cpus[cpu].cpu_type)
         {
                 case CPU_WINCHIP:
-                EAX = EDX = 0;
                 switch (ECX)
                 {
                         case 0x02:
diff --git a/src/cpu.h b/src/cpu.h
index 564691b..c3a770a 100644
--- a/src/cpu.h
+++ b/src/cpu.h
@@ -74,6 +74,14 @@ extern int cpu_multi;
 extern int cpu_hasrdtsc;
 extern int cpu_hasMSR;
 extern int cpu_hasMMX;
+extern int cpu_hasCR4;
+
+#define CR4_TSD  (1 << 2)
+#define CR4_DE   (1 << 3)
+#define CR4_MCE  (1 << 6)
+#define CR4_PCE  (1 << 8)
+
+extern uint64_t cpu_CR4_mask;
 
 extern uint64_t tsc;
 
diff --git a/src/ibm.h b/src/ibm.h
index d282f59..a44250f 100644
--- a/src/ibm.h
+++ b/src/ibm.h
@@ -154,7 +154,7 @@ union
 #define cr0 CR0.l
 #define msw CR0.w
 
-uint32_t cr2,cr3;
+uint32_t cr2, cr3, cr4;
 
 #define C_FLAG  0x0001
 #define P_FLAG  0x0004
diff --git a/src/x86_ops_mov_ctrl.h b/src/x86_ops_mov_ctrl.h
index e95dc5e..a32f0f8 100644
--- a/src/x86_ops_mov_ctrl.h
+++ b/src/x86_ops_mov_ctrl.h
@@ -19,6 +19,12 @@ static int opMOV_r_CRx_a16(uint32_t fetchdat)
                 case 3:
                 regs[rm].l = cr3;
                 break;
+                case 4:
+                if (cpu_hasCR4)
+                {
+                        regs[rm].l = cr4;
+                        break;
+                }
                 default:
                 pclog("Bad read of CR%i %i\n",rmdat&7,reg);
                 pc = oldpc;
@@ -49,6 +55,12 @@ static int opMOV_r_CRx_a32(uint32_t fetchdat)
                 case 3:
                 regs[rm].l = cr3;
                 break;
+                case 4:
+                if (cpu_hasCR4)
+                {
+                        regs[rm].l = cr4;
+                        break;
+                }
                 default:
                 pclog("Bad read of CR%i %i\n",rmdat&7,reg);
                 pc = oldpc;
@@ -110,6 +122,13 @@ static int opMOV_CRx_r_a16(uint32_t fetchdat)
                 cr3 = regs[rm].l;
                 flushmmucache();
                 break;
+                case 4:
+                if (cpu_hasCR4)
+                {
+                        cr4 = regs[rm].l & cpu_CR4_mask;
+                        break;
+                }
+
                 default:
                 pclog("Bad load CR%i\n", reg);
                 pc = oldpc;
@@ -143,6 +162,13 @@ static int opMOV_CRx_r_a32(uint32_t fetchdat)
                 cr3 = regs[rm].l;
                 flushmmucache();
                 break;
+                case 4:
+                if (cpu_hasCR4)
+                {
+                        cr4 = regs[rm].l & cpu_CR4_mask;
+                        break;
+                }
+
                 default:
                 pclog("Bad load CR%i\n", reg);
                 pc = oldpc;
diff --git a/src/x86_ops_msr.h b/src/x86_ops_msr.h
index 4ca1503..743af64 100644
--- a/src/x86_ops_msr.h
+++ b/src/x86_ops_msr.h
@@ -6,6 +6,11 @@ static int opRDTSC(uint32_t fetchdat)
                 x86illegal();
                 return 0;
         }
+        if ((cr4 & CR4_TSD) && CPL)
+        {
+                x86gpf("RDTSC when TSD set and CPL != 0", 0);
+                return 0;
+        }
         EAX = tsc & 0xffffffff;
         EDX = tsc >> 32;
         cycles--;