On Fri, Feb 5, 2016 at 12:24 AM, Andy Shevchenko
[off-list ref] wrote:

On Thu, Feb 4, 2016 at 10:06 PM, Peter Hurley [off-list ref] wrote:

quoted

quoted

Original sample:
00000000: 7f 45 4c 46 01 01 01 00  00 00 00 00 00 00 00 00   .ELF............
00000010: 02 00 03 00 01 00 00 00  19 8d 04 08 34 00 00 00   ............4...
00000020: 2c f2 00 00 00 00 00 00  34 00 20 00 04 00 28 00   ,.......4. ...(.

Received sample:
00000000: 7f 00 45 00 4c 00 46 00  01 00 01 00 01 00 00 00   ..E.L.F.........
00000010: 00 00 00 00 00 00 00 00  00 00 00 00 00 00 00 00   ................
00000020: 02 00 00 00 03 00 00 00  01 00 00 00 00 19 8d 04   ................

quoted

2) If you mean the NUL bytes for overruns, I could have some functional mode
   mis-branched in the N_TTY line discipline.

Yeah, this one.

quoted

What are the termios settings
   on the rx side?

I'm using this [1] tool with small patch applied that enables internal
loopback (TCIOM_LOOP).

Here are the calls

ret = cfsetspeed(&new_term, opts.baudrate);
cfmakeraw(&new_term);
new_term.c_cflag |= CREAD;
new_term.c_cflag &= ~CRTSCTS;
new_term.c_cc[VMIN] = 64;
new_term.c_cc[VTIME] = 8;
...
ret = tcflush(fd, TCIFLUSH);
ret = fcntl(fd, F_SETFL, 0);

[1] https://git.breakpoint.cc/cgit/bigeasy/serialcheck.git/

-- 
With Best Regards,
Andy Shevchenko