From 330a454af3e7ee064931a4e3d9443ffe8e618aec Mon Sep 17 00:00:00 2001
From: Ali Mashtizadeh <mashti@cs.stanford.edu>
Date: Thu, 10 Jul 2014 14:43:52 -0700
Subject: [PATCH] Improving AMD64 header

---
 sys/amd64/amd64.h   | 37 +++++++++++++++++++++----------------
 sys/amd64/machine.c |  5 +++++
 sys/amd64/trap.h    | 42 +++++++++++++++++++++++-------------------
 3 files changed, 49 insertions(+), 35 deletions(-)

diff --git a/sys/amd64/amd64.h b/sys/amd64/amd64.h
index b018520..2552d5e 100644
--- a/sys/amd64/amd64.h
+++ b/sys/amd64/amd64.h
@@ -150,22 +150,21 @@ typedef struct PACKED TaskStateSegment64 {
 
 #define RFLAGS_CF   0x00000001 /* Carry Flag */
 #define RFLAGS_PF   0x00000004 /* Parity Flag */
-#define RFLAGS_AF
-#define RFLAGS_ZF
-#define RFLAGS_SF
-#define RFLAGS_TF
-#define RFLAGS_IF
-#define RFLAGS_DF
-#define RFLAGS_OF
-// IOPL
-#define RFLAGS_NT
-
-#define RFLAGS_RF   0x00010000
-#define RFLAGS_VM   0x00020000
-#define RFLAGS_AC   0x00040000
-#define RFLAGS_VIF  0x00080000
-#define RFLAGS_VIP
-#define RFLAGS_ID
+#define RFLAGS_AF   0x00000010 /* Adjust Flag */
+#define RFLAGS_ZF   0x00000040 /* Zero Flag */
+#define RFLAGS_SF   0x00000080 /* Sign Flag */
+#define RFLAGS_TF   0x00000100 /* Trap Flag */
+#define RFLAGS_IF   0x00000200 /* Interrupt Enable Flag */
+#define RFLAGS_DF   0x00000400 /* Direction Flag */
+#define RFLAGS_OF   0x00000800 /* Overflow Flag */
+// IOPL (bits 12-13)
+#define RFLAGS_NT   0x00004000 /* Nested Task Flag */
+#define RFLAGS_RF   0x00010000 /* Resume Flag */
+#define RFLAGS_VM   0x00020000 /* Virtual 8086 Mode */
+#define RFLAGS_AC   0x00040000 /* Alignment Check */
+#define RFLAGS_VIF  0x00080000 /* Virtual Interrupt Flag */
+#define RFLAGS_VIP  0x00100000 /* Virtual Interrupt Pending */
+#define RFLAGS_ID   0x00200000 /* CPUID Supported */
 
 /*
  * Debug Registers
@@ -186,6 +185,12 @@ typedef struct PACKED TaskStateSegment64 {
 #define EFER_FFXSR  0x4000 /* Fast FXSAVE/FXRSTOR (AMD) */
 #define EFER_TCE    0x8000 /* Translation Cache Extension (AMD) */
 
+// SYSCALL/SYSRET
+#define MSR_STAR    0xC0000081
+#define MSR_LSTAR   0xC0000082
+#define MSR_CSTAR   0xC0000083
+#define MSR_SFMASK  0xC0000084
+
 #include "amd64op.h"
 
 #endif /* __AMD64_H__ */
diff --git a/sys/amd64/machine.c b/sys/amd64/machine.c
index 4948c2c..9c97d7d 100644
--- a/sys/amd64/machine.c
+++ b/sys/amd64/machine.c
@@ -76,6 +76,11 @@ void Machine_SyscallInit()
 {
     kprintf("Initializing Syscall... ");
 
+    wrmsr(MSR_STAR, SEL_KCS << 32 | SEL_UCS << 48);
+    wrmsr(MSR_LSTAR, 0);
+    wrmsr(MSR_CSTAR, 0);
+    wrmsr(MSR_SFMASK, 0);
+
     kprintf("Done!\n");
 }
 
diff --git a/sys/amd64/trap.h b/sys/amd64/trap.h
index 282f3e9..ad4c2a4 100644
--- a/sys/amd64/trap.h
+++ b/sys/amd64/trap.h
@@ -2,25 +2,25 @@
 #ifndef __TRAP_H__
 #define __TRAP_H__
 
-#define T_DE    0
-#define T_DB    1
-#define T_NMI   2
-#define T_BP    3
-#define T_OF    4
-#define T_BR    5
-#define T_UD    6
-#define T_NM    7
-#define T_DF    8
-#define T_TS    10
-#define T_NP    11
-#define T_SS    12
-#define T_GP    13
-#define T_PF    14
-#define T_MF    16
-#define T_AC    17
-#define T_MC    18
-#define T_XF    19
-#define T_VE    20
+#define T_DE    0	/* Divide Error Exception */
+#define T_DB    1	/* Debug Exception */
+#define T_NMI   2	/* NMI Interrupt */
+#define T_BP    3	/* Breakpoint Exception */
+#define T_OF    4	/* Overflow Exception */
+#define T_BR    5	/* BOUND Range Exceeded Exception */
+#define T_UD    6	/* Invalid Opcode Exception */
+#define T_NM    7	/* Device Not Available Exception */
+#define T_DF    8	/* Double Fault Exception */
+#define T_TS    10	/* Invalid TSS Exception */
+#define T_NP    11	/* Segment Not Present */
+#define T_SS    12	/* Stack Fault Exception */
+#define T_GP    13	/* General Protection Exception */
+#define T_PF    14	/* Page-Fault Exception */
+#define T_MF    16	/* x87 FPU Floating-Point Error */
+#define T_AC    17	/* Alignment Check Exception */
+#define T_MC    18	/* Machine-Check Exception */
+#define T_XF    19	/* SIMB Floating-Point Exception */
+#define T_VE    20	/* Virtualization Exception */
 
 #define T_CPU_LAST  T_VE
 
@@ -32,10 +32,14 @@
 #define T_IRQ_KBD       (T_IRQ_BASE + 1)
 #define T_IRQ_COM1      (T_IRQ_BASE + 4)
 #define T_IRQ_MOUSE     (T_IRQ_BASE + 12)
+
+// LAPIC Special Vectors
 #define T_IRQ_SPURIOUS  (T_IRQ_BASE + 24)
 #define T_IRQ_ERROR     (T_IRQ_BASE + 25)
 #define T_IRQ_THERMAL   (T_IRQ_BASE + 26)
 
+#define T_SYSCALL   60
+
 #define T_MAX   64
 
 typedef struct TrapFrame