boot panic on current(04.20)

[M. Warner Losh]

In message: <41877.147.83.40.213.1240324705.squirrel at webmail.entel.upc.edu>
            "Gustavo Perez Querol" <gperez at entel.upc.edu> writes:
: > lists
: >   boot panic on current(2009.04.20).it seems caused by usbus4
: >
: > Root mount waiting for: usbus4
: > uhub4: 8 ports with 8 removable, self powered
: > Root mount waiting for: usbus4
: > ugen4.2: <NEC> at usbus4
: > Fatal trap 12: page fault while in kernel mode
: > cpuid = 0; apic id = 00
: > fault virtual address   = 0x0
: > fault code              = supervisor read, page not present
: > instruction pointer     = 0x20:0xc08ed3a3
: > stack pointer           = 0x28:0xe4c38b40
: > frame pointer           = 0x28:0xe4c38b44
: > code segment            = base 0x0, limit 0xfffff, type 0x1b
: >                         = DPL 0,pres 1, def32 1, gran 1
: > processor eflags        = interrupt enabled, resume, IOPL = 0
: > current process         = 28 (usbus4)
: > trap number             = 12
: > panic: page fault
: > cpuid = 0
: > uptime: 5s
: 
:     I'm having the same problem with my laptop. It fails (if I remember
: well) when checkig an <O2 Micro> device (probably my card reader, don't
: know). When rebooting got to loader prompt, unload kernel and load
: /boot/kernel.old/kernel. This arrises a few questions :
: 
:         1.- How can I install a custom kernel under a different directory
:             under /boot. I did it, but I can't find how (google doesn't
:             help)I did it. I think there's a define when installing the
:             kernel.

make installkernel KERNEL=fred

will install the kernel into /boot/fred.  Might want to look add

# Debugging for use in -current
options 	KDB			# Enable kernel debugger support.
options 	DDB			# Support DDB.

to the kernel so you can get a traceback...

:         2.- nextboot allows me to choose a different kernel a give it
:             options, but is it possible to make the changes permanent ?

Not sure.  I don't use nextboot.

:    Well, now I'm csup down to current 18/04. Hope it will work :)
: 
:    Excuse me for the previous mail, that webmail I'm using is driving me
: more crazy :)

Web mail has been known to do that to me too.... :)

Warner