AVR-Chat

--- In AVR-Chat@yahoogroups.com, Zack Widup <w9sz@...> wrote:

> ... PDP-11/20, ... bootloader was ...
> toggle switches on the front ...

Well, since you bring it up, that's pretty much what I meant by 
the "traditional" use of the term "bootloader", formerly "bootstrap 
loader".  On power-up, the device has no program at all to execute or 
only the very simplest program that just looks for data to show up, 
moves that data into memory and at some point begins to execute the 
data as instructions.  On a mini-computer (I used Prime rather than 
DEC), the switch-entered loader was often only able to read paper tape 
and you then ran in a secondary loader from tape that was able to read 
the operating system from disk and then you were finally up.

By contrast, microcomputers have their applications programs ready to 
go when power is applied, so there is no bootstrap process at all.  The 
thing we've unfortunately got into the habit of calling a bootloader is 
only activated on request and then replaces the application image with 
a new one.  It's a "loader", but has no role in "boot"ing. I think it's 
a Flash loader or an application loader.

Graham.