Re: [Simulavr-devel] avrtest and simulavr vs simulavrxx

[Joerg Wunsch]

As Joel Sherrill wrote:

> I would like to make sure simulavrxx has all
> the capabilities avrtest and simulavr have.

> What is the list of reasons to use simulavr
> over simulavrxx?

avr-libc's testsuite uses the following features old simulavr has
which simulavrxx does not (yet) have:

-C option: provide a "coredump" after simulation finished

The coredump is actually a text file where the simulator state is
recorded when exiting.  Note that this is always done through atexit()
so it does not really matter *how* the simulator was exiting,
including a caught SIGINT.

We could probably even teach AVR-GDB to eventually be able to read
these dump files in place of a normal coredump file, which allows for
a post-mortem analysis of an aborted (e.g. through SIGINT) simulation.

avr-libc's testsuite mostly tests with AT90S8515 and ATmega128 targets
(which are present in simulavrxx), but some tests are run on a wider
list of target MCU types: AT90S2313, AT90S4414, AT90S8515, ATmega8,
ATmega16.  These are not yet supported by simulavrxx.  Further
unsupported targets include AT90S1200, ATmega32, ATmega103, and the
range of AT43USBxxx controllers.  AT90S4414 is essentially the same as
AT90S8515, only less memory, so that should be easy.  AT90S1200 is a
fairly different beast, and can probably be ignored as being long
obsolete.  Likewise for ATmega103 (though that one *might* be
interesting in case full ATmega103 emulation of the ATmega128 is
desired).  AT43USBxxx are fairly specific, and certainly not really
worth the while.  So ATmega8 (48/88 etc., too?), and ATmega16/32
(almost identical except for memory sizes) would remain as really
interesting additions.

The avr-libc testsuite uses the option -B <addr>, aka. --breakpoint
<addr>, in order to stop the simulation.  This option appears to be
the same as -T now (except that -T can also handle a symbol name when
simulating an ELF file), so maybe -B could be added as a synonym for
backwards compatibility?  Since simulavrxx uses the same command name
(simulavr) as the old implementation, this would be useful.

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

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