head dd 0
node equ ftdi_context
node.next equ ftdi_context.next_context
linkedlist:

  .add:
    push ebx
	mov	ebx, [head]				
	mov	[head], eax
	mov	[eax + node.next], ebx	
    pop ebx
	ret

  .delete:
    push ebx ecx
	mov ebx, eax	 ; eax - pointer to node for delete
	cmp eax, [head]
	jz  .unlink_head

  .getnext:
	cmp [ebx+node.next], eax
	jz  .unlink
	cmp [ebx+node.next], 0
	jz  .invalid_pointer
	mov ebx, [ebx+node.next]
	jmp .getnext

  .unlink:
	mov ecx, [eax+node.next]
	mov [ebx+node.next], ecx
	jmp @f


  .unlink_head:
	mov ebx, [eax+node.next]
	mov [head], ebx
  @@:
	mov   ecx, eax
	call  Kfree
  .invalid_pointer:
    pop   ecx ebx
	ret

  .gethead:
  	mov	eax, [head]
  	ret

restore node
restore node.next