---

yaml
---
r: 3323
b: refs/heads/master
c: 860e8fd
h: refs/heads/master
i:
  3321: 0683d45
  3319: fd9c989
v: v3

Author: Eric Holk

[refs]

@@ -1,2 +1,2 @@
 ---
-refs/heads/master: 98dee91f2568522bc129f8cffcaa2879b43646c3
+refs/heads/master: 860e8fd98b07cc0dfbb3ff33124778c2225ba81d

trunk/src/rt/arch/i386/_context.s

@@ -13,15 +13,17 @@ Saves a set of registers. This is used by our implementation of
 getcontext.
 
 The registers_t variable is in (%esp)
-*/
-	
-.globl get_registers
-get_registers:
-	movl 4(%esp), %eax
-	movl %eax, 0(%eax)
+*/	
+
+// swap_registers(registers_t *oregs, registers_t *regs)
+.globl swap_registers
+swap_registers:
+    // save the old context
+    movl 4(%esp), %eax
+	//movl %eax, 0(%eax)
 	movl %ebx, 4(%eax)
-	movl %ecx, 8(%eax)
-	movl %edx, 12(%eax)
+	//movl %ecx, 8(%eax)
+	//movl %edx, 12(%eax)
 	movl %ebp, 16(%eax)
 	movl %esi, 20(%eax)
 	movl %edi, 24(%eax)
@@ -43,17 +45,12 @@ get_registers:
     movl %esp, 28(%eax)
 	movl %ecx, 48(%eax)
 
-	// return 0
-	xor %eax, %eax
-	jmp *%ecx
-
-.globl set_registers
-set_registers:
-	movl 4(%esp), %eax
+    // restore the new context
+    movl 4(%esp), %eax
 
 	movl 4(%eax), %ebx
 	// save ecx for later...
-	movl 12(%eax), %edx
+	//movl 12(%eax), %edx
 	movl 16(%eax), %ebp
 	movl 20(%eax), %esi
 	movl 24(%eax), %edi
@@ -71,36 +68,5 @@ set_registers:
 	push %ecx
 	popf
 
-    // get ready to return.
-	mov 48(%eax), %ecx
-	push %ecx	
-	
-	// okay, now we can restore ecx.
-	movl 8(%eax), %ecx
-
-	// return 1 to the saved eip
-	movl $1, %eax
-	ret
-
-// swap_registers(registers_t *oregs, registers_t *regs)
-.globl swap_registers
-swap_registers:
-    // %eax = get_registers(oregs);
-    movl 4(%esp), %eax
-    push %eax
-    call get_registers
-        
-    // if(!%eax) goto call_set
-    test %eax, %eax
-    jz call_set
-
-    // else
-    addl $4, %esp
-    ret
-        
-call_set:
-    // set_registers(regs)
-    movl 12(%esp), %eax
-    movl %eax, 0(%esp)
-    call set_registers
-    // set_registers never returns
+    // Return!
+    jmp *48(%eax)

trunk/src/rt/arch/i386/context.cpp

@@ -5,17 +5,12 @@
 #include <stdio.h>
 #include <stdlib.h>
 
-//extern "C" uint32_t CDECL get_registers(registers_t *regs) 
-//  asm ("get_registers");
 extern "C" uint32_t CDECL swap_registers(registers_t *oregs, 
                                          registers_t *regs)
   asm ("swap_registers");
 
 context::context()
-  : next(NULL)
 {
-  //get_registers(&regs);
-  swap_registers(&regs, &regs);
 }
 
 void context::swap(context &out)
@@ -24,13 +19,15 @@ void context::swap(context &out)
 }
 
 void context::call(void *f, void *arg, void *stack) {
+  // Get the current context, which we will then modify to call the
+  // given function.
+  swap(*this);
+
   // set up the trampoline frame
   uint32_t *sp = (uint32_t *)stack;
 
   // Shift the stack pointer so the alignment works out right.
-  sp = align_down(sp) - 2;
-
-  *--sp = (uint32_t)this;
+  sp = align_down(sp) - 3;
   *--sp = (uint32_t)arg;
   *--sp = 0xdeadbeef;