_MAINTHREAD:
	.comm  eax_save,4
        .globl _MAINTHREAD	

 










        .comm   _eax_save,4

        .globl  _SWITCH
_SWITCH:
        movl    %eax,_eax_save          # save the value of eax
        movl    4(%esp),%eax            # move pointer to t1 into eax
        movl    %ebx,8 (%eax)         # save registers
        movl    %ecx,12 (%eax)
        movl    %edx,16 (%eax)
        movl    %esi,24 (%eax)
        movl    %edi,28 (%eax)
        movl    %ebp,20 (%eax)
        movl    %esp,0 (%eax)         # save stack pointer
        movl    _eax_save,%ebx          # get the saved value of eax
        movl    %ebx,4 (%eax)         # store it
#for the next inscruction : rember that esp is the esp from the thread
#image not from the caller
        movl    0(%esp),%ebx            # get return address from stack into ebx
        movl    %ebx,32 (%eax)          # save it into the pc storage

        movl    8(%esp),%eax            # move pointer to t2 into eax

        movl    4 (%eax),%ebx         # get new value for eax into ebx
        movl    %ebx,_eax_save          # save it
        movl    8 (%eax),%ebx         # retore old registers
        movl    12 (%eax),%ecx
        movl    16 (%eax),%edx
        movl    24 (%eax),%esi
        movl    28 (%eax),%edi
        movl    20 (%eax),%ebp
        movl    0 (%eax),%esp         # restore stack pointer
        movl    32 (%eax),%eax          # restore return address into eax
        movl    %eax,4(%esp)            # copy over the ret address on the stack
        movl    _eax_save,%eax

#ret pulls the address off of the stack  (the stack of this thread)
        ret