Re: [PATCH] serial: DCC(JTAG) serial and console emulation support

Mike Frysinger
2010-10-07T21:05:53Z

On Thu, Oct 7, 2010 at 16:59, Daniel Walker wrote:
> On Thu, 2010-10-07 at 16:47 -0400, Mike Frysinger wrote:
>> On Thu, Oct 7, 2010 at 16:06, Daniel Walker wrote:
>> > On Thu, 2010-10-07 at 16:02 -0400, Mike Frysinger wrote:
>> >> how is that any different from:
>> >> ln -s ttyJ0 /dev/ttyS0
>> >
>> > It has the same major and minors as ttyS* does. So you don't have to run
>> > anything on the target.
>>
>> i dont see how those things are related.  the major/minor are
>> irrelevant, unless you've already hard coded these in some app that
>> creates device nodes manually (instead of mdev/udev), but even then
>> that's something that "needs to be run on the target".  and both
>> already have config support to transparently do something like
>> "symlink ttyS# to XXX" as XXX is created.
>
> Something does ultimately run on all targets, the issues is does the
> person debugging have the ability to change it .. It's not always the
> case that they can change it. The userspace may not have udev at all.
> The userspace may consist of a single binary .. I'm not making any
> assumptions about the userspace here, it can be anything.

then there is already a static rootfs with pre-populated /dev which
would be fixed, or the single binary fixed. if the options are "my
system works" or "my system doesnt work", i cant imagine people would
continue to attempt to use "/dev/ttyS#" if it didnt exist or didnt
work.
-mike