
Modified October 04 to make erase command guards in mymon work.



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In this directory is a machine code monitor and other little bits for
embedded systems using the Hitachi H8S processor, including a simple
flash loader, mixflash.


The main ROM image for the flash loader itself is created with the target mflo.

To reflash the flash loader, you also need a copy of mfhi.

Instructions for reflashing:

   1. Download mfhi into flash using the existing loader.  This loads at address 80000. 
   You need to use the EA command to clear that flash before the download.
   Use the monitor to check it is there.

   2. Jump to mfhi using the monitor  mymon: go 80202 (actually 70202 with the current makefile).

   3. Check that you are indeed running the mfhi by inspecting the response to the 'v'
   command.  This should print the load point and should not be 0x80.

   4. Erase the old flash loader with the 'BER' command.

   5. Download the new version of mflo as a normal download.

   6. Enter the monitor and check it is indeed there, then reset the card.

Do not reset the card between steps 4 and 5.  If you have a failure, e.g. you do
reset the card between 4 and 5, then power up with address line A19 temporarily
grounded (just for a second after reset) and the mfhi will be entered and run ok.


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To cause auto entry of the loaded image, we need to add

 set 0x1FFF0 to 0x1234

We can probably do that with the following line:
  :020000040001F9
  :02FFF0001234xx
where xx is the correct checksum 

But I use the monitor
  $ ihw 1fff0 12
  $ ihw 1fff1 34

