Re: port-evbarm/40311: No kernel symbols on tsarm

[Lloyd Parkes <lloyd%must-have-coffee.gen.nz@localhost>]

The following reply was made to PR port-evbarm/40311; it has been noted by 
GNATS.

From: Lloyd Parkes <lloyd%must-have-coffee.gen.nz@localhost>
To: Martin Husemann <martin%duskware.de@localhost>
Cc: jmmv%NetBSD.org@localhost,
 gnats-bugs%netbsd.org@localhost
Subject: Re: port-evbarm/40311: No kernel symbols on tsarm
Date: Wed, 21 Jan 2009 19:31:13 +1300

 While it works (modulo the semi-colon), I realised that it doesn't  
 address the original issue that got me started on all this. The  
 symbols need to be loaded before DDB is initialised so that whenever  
 you might drop to DDB, you have them available.
 
 The requirements we have seem to be:
 
        1) Symbols are necessary for module loading.
        2) Symbols make DDB usable.
        3) There is a mutex that should be initialised well after the  
 symbols are loaded.
 
 This raises the questions of what uses the mutex, and when is it  
 used? If the symbols are loaded nice and early, just before DDB is  
 initialised like they used to be, and then the kernel drops to DDB  
 before the mutex is initialised, what happens? Do the symbol lookups  
 trip over the uninitialised mutex?
 
 I simply don't have the time now that I'm back at work to look at this.
 
 If DDB works with the symbols being loaded after it is initialised  
 (and it probably will), then I think we can cope with a small window  
 where DDB doesn't have any symbols available to it until someone gets  
 some some time to look at it (and we run out of more important things  
 to worry about).
 
 Cheers,
 Lloyd