Clean up handling of stack frames.

[pintos-anon] / src / threads / switch.S

diff --git a/src/threads/switch.S b/src/threads/switch.S
index a7c27fb03eb8fc3cb73ccee19f07ef21438d61ea..5b661ec1f1fd88924704dc95c2238987479dc6ab 100644 (file)
--- a/src/threads/switch.S
+++ b/src/threads/switch.S
@@ -1,7 +1,4 @@
-#### 0(%esp) - old registers
-#### 16(%esp) - return address
-#### 20(%esp) - current thread
-#### 24(%esp) - new thread
+#include "switch.h"
 
         .globl thread_switch 
 thread_switch:
@@ -18,14 +15,14 @@ thread_switch:
        mov thread_stack_ofs, %edx
 
        # Save current stack pointer to old thread's stack, if any.
-       movl 20(%esp), %eax
+       movl SWITCH_CUR(%esp), %eax
        test %eax, %eax
        jz 1f
        movl %esp, (%eax,%edx,1)
 1:
 
        # Restore stack pointer from new thread's stack.
-       movl 24(%esp), %ecx
+       movl SWITCH_NEXT(%esp), %ecx
        movl (%ecx,%edx,1), %esp
 
        # Restore caller's register state.