Re: [Discuss-gnuradio] USRP2 firmware build

[Matt Ettus]

Jeff Long wrote:
> Generated a new txrx.bin using EDK101 and put it on the SD
> card.  Works!  I'm assuming that's the correct app, based on
> strings on the provided SD.  BTW, is any of this documented
> yet?

Yes, txrx is the correct app to use, and is the one which is on the SD 
card which I ship out.  No, we don't really have this written anywhere.  
I've been putting stuff on the USRP2 FAQ page on the wiki, but clearly 
this is a lot which still needs to be documented.

> Where do printf's go to?

They go to the serial port on the right side of the USRP2, between the 
two daughterboards.  You would have to connect a TTL-level serial port 
to it, at 230,400 baud.

> Using -Os vs. -O2 shaves off another 500 bytes if you ever
> need the space.  Takes txrx.bin from 26028 to 25484 bytes.

I was thinking that -Os would probably be a good thing to try.  Having 
only 32K of RAM can be a bit constraining.

> The function __udivdi3 is 1836 bytes long, and is only used
> in print_uint64, which is used only in printf_fxpt_freq.
> That might be something to get rid of.


Wow, 1836 bytes is a lot.

I'm really glad to have your feedback and bug reports on this.  It will 
definitely help blaze the trail for other users.

Thanks,
Matt