recompiled 6.0 does not boot -- need help !!

Bartosz Fabianowski freebsd at chillt.de
Tue Nov 22 22:17:26 GMT 2005


> now, when i think of it, i suspect the reason might be CPUTYPE=pentium-m 

The relevant bug is 75898, which I filed almost a year ago. It has been 
fixed and MFC'd though, so it should not be affecting 6.0-release (I am 
using CPUTYPE=pentium-m on 6.0 myself). Most likely, something else went 
wrong.

Still, all is not lost. When your system is starting up, hit any key 
after the BIOS has finished initializing the computer and before FreeBSD 
has given you any output on the screen. You'll end up in a prompt where 
you can select the boot loader. When you installed a new kernel, the 
previous loader got renamed to loader.old and that's the one you want to 
run. On my system, the prompt is:

Default: 0:ad(0,a)/boot/loader
boot:

Simply copy the default line and append ".old", as in:

boot: 0:ad(0,a)/boot/loader.old

Once the boot loader has started up, it will count down a few seconds 
before starting the kernel. Since you're saying your kernel might be 
b0rked as well, you should hit any key but enter to get another prompt. 
It will look like this:

OK

Here, you can tell the loader to boot the previous kernel:

OK boot /boot/kernel.old

This should get you up and running again. You certainly should try to 
build a new, working kernel. But you should *absolutely* make sure to 
back up loader.old and kernel.old first, because if you install another 
kernel, those two will be overwritten by your current, broken loader and 
kernel. Simply run (as root):

cp /boot/loader.old /boot/loader.good
cp -R /boot/kernel.old /boot/kernel.good

This way, you can always revert to loader.good and kernel.good if 
something goes wrong. Actually, it doesn't hurt to have a working kernel 
and loader lying around just in case. Update it periodically and you 
will always have a little safeguard in case you render your system 
unbootable.

- Bartosz


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