Switch / Case Optimization

I've read through this thread:
http://www.keil.com/forum/8020/

and I understand that:
1. For "a few" case values, I'll get a series of if / else if's. Not sure how many that is.
2. If the case values follow the format {0, 1, 2, ...}, I'll get a jump table. Sometimes.
3. Otherwise, I'll get a function call to the super-flexible library.

My problem is that I have a switch-based state machine that necessarily starts at 0xFF and uses a change in state as more of a yield() function in an RTOS. Something like this:

unsigned char state1;
unsigned char state2;

void main(void)
{
   state1 = Read_Program_Memory(ADDR1);
   state2 = Read_Program_Memory(ADDR2);
   while(1)
   {
      if(state1)
      {
         thread1();
      }
      thread2();
   }
}

void thread1(void)
{
   switch(state1)
   {
   case 0xFF:
      //do something
      //...
      state1 = 0xFE:
   case 0xFE:
      if(!condition_to_wait_for)
      {
         break;
      }
      //do some more
      //...
      //don't need to run this ever again
      state1 = 0x00:
      Write_Program_Memory(ADDR1, 0x00);
   }
}

I really don't care what the case values are, but 0xFF has to be present for initialization and on top to make the first fall-through work. Is there a good, readable way to get a jump table out of this, so as to avoid the library call?

Thanks!
Aaron