Ctrl-Alt-ESC during boot

Chuck Tuffli chuck_tuffli at agilent.com
Wed Jan 26 14:58:38 PST 2005

On Wed, Jan 26, 2005 at 01:57:20PM -0800, Matthew Dillon wrote:
> :On Wed, 26 Jan 2005, Chuck Tuffli wrote:
> :
> :> boot -d does drop the OS into ddb, but after continuing, ctrl-alt-esc
> :> doesn't break into ddb.
> :
> :I discovered (the hard way) that there is a kernel config option
> :SC_DISABLE_DDBKEY which has that effect.  Is there any chance that
> :the kernel on the CD was compiled with that option?  I suppose only(?)
> :Matt would know.  The option is not in the GENERIC kernel but is
> :in LINT.
>     I'm a bit confused.  SC_DISABLE_DDBKEY disables your ability to
>     enter the debugger through ctl-alt-esc.  Why would you want to have
>     that option on by default?

I don't have this set ...

>     ctl-alt-esc does eventually work if I boot -d and then 'cont', but
>     you have to realize that the system disables interrupts during early boot
>     so it won't see a ctl-alt-esc that early in the boot sequence.

This might explain what is going on. The hang occurs in
autoconf.c/configure() inside the call to spl0().

Chuck Tuffli
Agilent Technologies

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