From fcec69efdc2e65ef10e6a295ffb0582bca42177b Mon Sep 17 00:00:00 2001
From: Jeremy Soller <jackpot51@gmail.com>
Date: Thu, 8 Sep 2016 15:53:45 -0600
Subject: [PATCH] remove bochs breaks

---
 arch/x86_64/src/interrupt/syscall.rs | 10 ++++------
 arch/x86_64/src/lib.rs               | 12 ++++--------
 arch/x86_64/src/start.rs             |  3 +--
 3 files changed, 9 insertions(+), 16 deletions(-)

diff --git a/arch/x86_64/src/interrupt/syscall.rs b/arch/x86_64/src/interrupt/syscall.rs
index 7dfaf38..7133906 100644
--- a/arch/x86_64/src/interrupt/syscall.rs
+++ b/arch/x86_64/src/interrupt/syscall.rs
@@ -13,17 +13,16 @@ pub unsafe extern fn syscall() {
             let d;
             let e;
             let f;
-            asm!("xchg bx, bx" : "={rax}"(a), "={rbx}"(b), "={rcx}"(c), "={rdx}"(d), "={rsi}"(e), "={rdi}"(f)
+            asm!("" : "={rax}"(a), "={rbx}"(b), "={rcx}"(c), "={rdx}"(d), "={rsi}"(e), "={rdi}"(f)
                 : : : "intel", "volatile");
 
             a = syscall(a, b, c, d, e, f);
         }
 
-        asm!("xchg bx, bx" : : "{rax}"(a) : : "intel", "volatile");
+        asm!("" : : "{rax}"(a) : : "intel", "volatile");
     }
 
-    asm!("xchg bx, bx
-        push fs
+    asm!("push fs
         push rax
         mov rax, 0x18
         mov fs, ax
@@ -33,8 +32,7 @@ pub unsafe extern fn syscall() {
     inner();
 
     // Interrupt return
-    asm!("xchg bx, bx
-        pop fs
+    asm!("pop fs
         iretq"
         : : : : "intel", "volatile");
 }
diff --git a/arch/x86_64/src/lib.rs b/arch/x86_64/src/lib.rs
index fdcea65..61fb547 100644
--- a/arch/x86_64/src/lib.rs
+++ b/arch/x86_64/src/lib.rs
@@ -48,8 +48,7 @@ macro_rules! interrupt {
             }
 
             // Push scratch registers
-            asm!("xchg bx, bx
-                push rax
+            asm!("push rax
                 push rcx
                 push rdx
                 push rdi
@@ -67,8 +66,7 @@ macro_rules! interrupt {
             inner();
 
             // Pop scratch registers and return
-            asm!("xchg bx, bx
-                pop fs
+            asm!("pop fs
                 pop r11
                 pop r10
                 pop r9
@@ -95,8 +93,7 @@ macro_rules! interrupt_error {
             }
 
             // Push scratch registers
-            asm!("xchg bx, bx
-                push rax
+            asm!("push rax
                 push rcx
                 push rdx
                 push rdi
@@ -114,8 +111,7 @@ macro_rules! interrupt_error {
             inner();
 
             // Pop scratch registers, error code, and return
-            asm!("xchg bx, bx
-                pop fs
+            asm!("pop fs
                 pop r11
                 pop r10
                 pop r9
diff --git a/arch/x86_64/src/start.rs b/arch/x86_64/src/start.rs
index c99dd64..d382f28 100644
--- a/arch/x86_64/src/start.rs
+++ b/arch/x86_64/src/start.rs
@@ -204,8 +204,7 @@ pub unsafe extern fn kstart_ap(stack_start: usize, stack_end: usize) -> ! {
 
 pub unsafe fn usermode(ip: usize, sp: usize) {
     // Test usermode
-    asm!("xchg bx, bx
-        mov rax, 0x2B
+    asm!("mov rax, 0x2B
         mov ds, ax
         mov es, ax
         mov fs, ax