compiled newlib, need to hook up the system calls

kernel/scheduler.S

@@ -1,12 +1,31 @@
-.code32 
-.extern schedule_next_task
+
+
+.code32
 .global yield 
-yield:
-    cli 
-    pushal 
-    push %esp 
-    call schedule_next_task
-    movl %eax, %esp 
-    popal 
-    sti 
-    ret
+.extern schedule_next_task 
+yield: # void yield()
+    cli
+
+    pushfl          
+    pushl %cs
+
+    movl 8(%esp), %eax      
+    pushl %eax
+
+    movl 4(%esp), %ebx      # Get CS
+    movl %ebx, 8(%esp)      # Move CS over Old EIP
+    movl 0(%esp), %ebx      # Get Return EIP
+    movl %ebx, 4(%esp)      # Move Return EIP over CS
+    addl $4, %esp           # Adjust stack pointer up.
+
+    # the stack now looks like a hardware interrupt just happened, even though we never called one.
+
+    pushal
+    
+    pushl %esp
+    call switch_context
+    movl %eax, %esp
+
+    popal
+    sti
+    iret