Re: [Kgdb-bugreport] [PATCH] Kill kgdb_serial

[Tom Rini]

On Thu, Mar 11, 2004 at 01:33:40PM -0800, George Anzinger wrote:

> Tom Rini wrote:
> 
> >>I am afraid I don't quite understand what he was saying other than early 
> >>init stuff.  On of the problems with trying early init stuff, by the way, 
> >>is that a lot of things depend on having alloc up and that happens rather 
> >>late in the game.
> >
> >
> >I assume you aren't talking about kgdb stuff here (or what would be the
> >point of going so early) but I believe he was talking about allowing for
> >stuff that could be done early, to be done early.
> 
> One of the issues with the UART set up is registering the interrupt handler 
> with the kernel.  It will fail if alloc is not up.  The -mm patch does two 
> things with this.  a) It tries every getchar to register the interrupt 
> handler, and b) it has a module init entry to register it.  This last will 
> happen late in the bring up and is safe.  a) is there to get it ASAP if you 
> are actually using kgdb during the bring up.

There's two ways to look at this.
- All the more reason to acknowledge that the earliest you can safely
  get into KGDB is point X, where X is where alloc works, mappings done
  if needed, etc, etc, and IFF we change things slightly in kgdboe so
  that it can call kgdb_schedule_breakpoint() if it needs to as an
  initial break, and handle setting kgdb_serial to the serial driver in
  kgdb_arch_init, or something, and remove all of the extra kludges to
  get us a few lines / function calls earlier on.
- More and more special cases.

Roughly. :)

-- 
Tom Rini
http://gate.crashing.org/~trini/
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