AVR-Chat

Back when I used a PDP-11/20, the hardware bootloader was a series of 
toggle switches on the front of the unit.  I'm glad those days are gone!
:-)

Zack

On Wed, 2 Jul 2008, Graham Davies wrote:

> --- In AVR-Chat@yahoogroups.com, "Frank" <transistortoaster@...> wrote:
>
>> For the hardware bootloader,
>> I'm a bit confused.
>
> Maybe you could clarify what you mean by a "hardware bootloader".  Many
> AVRs have the ability to sort-of cordon off part of the Flash for a
> program that can accept a new application firmware image from somewhere
> (such as the serial port) and program it into the main Flash.  Atmel
> refers to this as a bootloader, although traditionally a bootloader
> does something quite different.  But, this "bootloader" is still
> firmware that you program into the chip and that disappears when you
> erase the chip.  A hardware bootloader, in my experience, is held in
> the chip in ROM (and so can't be erased) and loads the application
> (perhaps from a serial port) into RAM and executes it from there.  The
> AVRs don't have this.  They have no ROM and can't execute from RAM.
>
> Graham.
>
>
>