AVR-Chat

At 07:56 AM 12/25/2004, nayoo1979 wrote:



>Hi all,
>
>I am trying to implement an ATMega8 bootloader. If anybody has
>happened to got the experiences before, pls share with me.
>
>I will be very grateful to you, if any of you can kindly share with
>me any of the below:
>1. where to find the useful information online
>2. where to find the sample source codes.
>3. Any Experiences in implementing bootloader
>4. How to download the Bootloader

Well, you should chat with the other fellow, you are both trying to do the 
same thing.

Read the atmel app notes.

Usually, you implement the boot loader through a USART interface, but that 
isn't required. It's just the most conventional way.  You have it try to 
connect with a PC at boot, and if it can't connect within a reasonable time 
(10 seconds?) then you allow the main program to run.

Nothing prevents you from doing a loader mechanism inside the main program 
either, but that is a more advanced project, and much more "delicate".  The 
nice thing about the boot block is that you can protect it so that the boot 
loader can't destroy itself accidentally.  So, even if the main program is 
totally erased, the boot loader still works.