removed pdclib, strange things were happening..., user shell kinda works now

kernel/scheduler.S

@@ -6,24 +6,31 @@
 yield: # void yield()
     cli
 
-    pushfl          
-    pushl %cs
+    popl %ecx
+    
+    pushfl          // EFLAGS
+    pushl %cs       // CS   
+    pushl %ecx   // EIP
 
-    movl 8(%esp), %eax      
+    pushal
+    call send_eoi_master
+
+    xor %eax, %eax
+    mov %ds, %ax
     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.
-    
-    pushal
+    mov $0x10, %ax
+    mov %ax, %ds
+    mov %ax, %es
     
     pushl %esp
     call switch_context
     movl %eax, %esp
 
+    popl %eax
+    mov %ax, %ds
+    mov %ax, %es
+
     popal
     sti
     iret