Re: [Simulavr-devel] simulavr is very unreliable executing a bootloader

[Joerg Wunsch]

As Albrecht Frenzel wrote:

> The strange thing: sometimes pc gets loaded with the correct pc 
> 0x7e00 and it is possible to step through the code using the same 
> .elf-file.

You can always set the current PC address in GDB before proceeding:

set $pc = 0x7e00

> Regarding Illegal opcode 'ff ff': wouldn't it be better to simply 
> stop simulavr instead of terminating? That would give a chance to 
> investigate.

As the AVR (undocumentedly) treats opcode ffff as a NOP, I think 
the simulator could even just continue.  There are possible 
scenarios where this feature could be used deliberately, e. g. 
by including a patch area in the code that is simply run through 
as long as it is ffff but which can be written later on to 
include additional features.
-- 
cheers, Joerg               .-.-.   --... ...--   -.. .  DL8DTL

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