On Mon, 2015-01-12 at 11:27 -0600, Paul Clarke wrote: > On 01/12/2015 03:48 AM, Michael Ellerman wrote: > > We get way too many bug reports that say "the kernel is hung in > > prom_init", which stems from the fact that the last piece of output > > people see is "returning from prom_init". > > > > The kernel is almost never hung in prom_init(), it's just that it's > > crashed somewhere after prom_init() but prior to the console coming up. > > > > The existing message should give a clue to that, ie. "returning from" > > indicates that prom_init() has finished, but it doesn't seem to work. > > Let's try something different. > > > > This prints: > > > > Calling quiesce... > > Shutting down Open Firmware, booting Linux via __start() ... > > > > Which hopefully makes it clear that prom_init() is not the problem, and > > although __start() probably isn't either, it's at least the right place > > to begin looking. > > I'm very much in favor of anything that increases usability or decreases > confusion. > > I worry about confusion caused by any phrase that begins "Shutting > down.." Even if accurate, I wonder if something more positive that > indicates that, at least at this point, things are continuing to proceed > along would be preferred.
True. > Perhaps something like "Transferring control from Open Firmware to > kernel (via __start) ...". Yeah, that's not quite accurate either :) Linux already has control, but up until that point it is running alongside OF and using its services. After prom_init() returns we take over the machine entirely. Maybe "Leaving Open Firmware, booting Linux ..." Or just "Booting Linux ...". > (Do we know for certain that what is about to be invoked is "Linux" > per-se, or can it be something else that has a "__start"?) Yes it's Linux. Although we treat prom_init() as a separate thing, it's just linked into the regular kernel binary. So the "transfer" here is really just a function call. But it signifies a switch from code that runs alongside Open Firmware (prom_init()), to code that doesn't (the rest of the kernel). We have talked about actually linking them separately but we've never bothered, it wouldn't buy us much. cheers _______________________________________________ Linuxppc-dev mailing list Linuxppc-dev@lists.ozlabs.org https://lists.ozlabs.org/listinfo/linuxppc-dev
