Re: Flag day for bootloader + kernel?

I wrote:
> [email protected] wrote:
> 
> > it appears that there has crept in a "flag day" on the sgimips
> > port.  The thing is this:
> > 
> >  o A -current kernel requires a newer bootloader than the one
> >    which came with 4.0
> >  o The new bootloader from -current cannot boot a 4.0 kernel (but
> >    a -current kernel is fine)
> > 
> > When I tried to boot a 4.0 kernel with the new bootloader (trying
> > to be "careful" when upgrading), what I got was what is shown
> > below.
> 
> It's a known problem.
> 
> Could you please try the attached patch with each combinations?
> 
> With this patch:
> - the newer bootloader (Rev 1.5) can load both newer -current kernels
>   and 4.0 kernels
> - 4.0 bootloader can load newer -current kernels
>   (without kernel symbol support)
> - old -current bootloader (Rev 1.4) can still load newer -current kernels
>   (without kernel symbol support)
> - newer -current kernels can still be loaded via netboot with
>   proper root device 
> - but -current kernels between ~4.99.50 and ~4.99.69 won't work with
>   the newer bootloader
>   (they could be loaded properly but root partition won't be recognized
>    properly, and there is something wrong around cngetc() on com(4) at mace
>    that causes reboot on "root device:" prompt)
> - loading kernels on IP12 (which doesn't have ARCBIOS) is not tested at all
>   (I wonder if argv[0] passed from BIOS is vaild or not on IP12)

I've committed machdep.c changes, which allow 4.0 bootloader
load -current kernels.
(i.e. recoginize boot partition properly so that we don't get reboot
 by watchdog on boot device prompt)

If there is no objection, I'll also bump BOOTINFO_MAGIC in bootinfo.h
(which requires updating bootloader for users to use ksyms(4) etc)
in a next few days.
---
Izumi Tsutsui