RELENG_7 and HEAD: bge causes system hang

韓家標 Bill Hacker askbill at
Mon Nov 26 12:38:08 PST 2007

Robert Watson wrote:
> On Mon, 26 Nov 2007, Cristian KLEIN wrote:

(this probbaly justifies a new thread ... but..)

>> That is very unfortunate. Newer laptops don't come with a serial port 
>> anymore. As far as I know, using USB-to-serial converters won't work.
> Many notebooks do, however, have firewire.  I've not read the firewire 
> code or used firewire for debugging, so I can't comment on how effective 
> breaks are, but I can say that one of the neatest things about firewire 
> is that you can inspect the kernel memory of a host remotely even when 
> it's frozen solid, which is pretty cool.  So if you have a notebook that 
> is also without firewire, you may indeed be out of luck, but with 
> firewire, you have a nice new option.

> I think getting an MPSAFE syscons would be desirable, but it's a 
> non-trivial piece of work, especially if you take into account that it's 
> tangled up in the tty code.  If you have firewire, that may be a useful 
> option.  However, I would agree with an assertion that notebooks are 
> becoming less useful as a development platform because of the omission 
> of a real serial port.


A) Notebooks are at over 50% of new sales and climbing, so it isn't just as 
devel platforms - but as sources of 'field reports' of tester / user encountered 
problems that will become an ever-growing challenge.

Worse, unlike a conventional MB, one cannot just plug in a bus card and emulate 
(or substitute for) the key subsystem involved, so at some point those laptops 
need to be accomodated.

B) It isn't just laptops. Mac Mini-like, small-format packaging is taking 
another chunk out of the field. These, too are legacy I/O challenged as well as 
limited in bus sockets.

C) Even full-ATX size MB have long-since begun shedding (external) serial ports 
as well as PS2 mouse & keyboard-ports, may not even ship with the cables or 
connectors to attach to such 'legacy' serial connectors as reamin - usually 
well-hidden somewhere on the MB.

D) Much as I like FW, I haven't seen any indication that it has a guarantee of 
survival or universality any greater than once-common IRDA did.

Too many price-driven decisions favor 'good enough' and far more common USB 2.

Something will be needed soon/already to cover the general gap of missing SIO.

We probably *can* count on audio I/O not going away, so perhaps ASCII to fsk  - 
or even text to speech.



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