Re: [avr-libc-dev] functions to write data into application flash section

[Joerg Wunsch]

As Thomas Richter wrote:

> Can I write in the Application Flash Section during a running
> application?

You can, but the code executing the SPM instruction must be located in
the bootloader area (as described by the fuses).  Also, any code in
the non-read-while-write memory area (i.e. in the lower part of flash
ROM) will stop while the SPM is being executed.

Nothing prevents your application from calling the actual SPM handler
that is located in the bootloader area though, and that handler then
simply returns into the application (in low memory).

Note that this limitation is not inherent to the avr/boot.h
implementation but to the AVR itself.  The only exception are some
recent ATtinys as they do not have a designated boot loader area at
all, so for them, if the SPM instruction is enabled at all (again, by
a fuse), it will be available from everywhere.

-- 
cheers, J"org               .-.-.   --... ...--   -.. .  DL8DTL

http://www.sax.de/~joerg/                        NIC: JW11-RIPE
Never trust an operating system you don't have sources for. ;-)