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Date: Fri, 11 Nov 2016 06:43:22 +0100
From: Polytropon <freebsd@edvax.de>
To: Mick mtn <mtnmickmt@gmail.com>
Cc: freebsd-questions@freebsd.org
Subject: Re: Newbie Question: is there a rescue mode or shell access from
 loader?
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On Thu, 10 Nov 2016 22:30:18 -0700, Mick mtn wrote:
> FreeBSD 11.0R p2
> on a macbook pro,
> 
> System was working, added some drivers to loader.conf, now system panics
> and reboots after 15 seconds.  one of the errors I can see relates to
> module vesa can not register 17
> vesa.ko already loaded
> 
> I can escape too the loader prompt.
> But do not see how to edit files from the loader prompt.
> Can anyone help me get to the shell?

The classic way is to interrupt the boot by repeatedly pressing
the space bar until you reach the "kernel prompt". Here you can
perform the "unload" command and then resume booting into single
user mode where you can mount r/w your / or /boot partition and
undo the change in the loader.conf file.

See "12.2.3. Stage Three" in The FreeBSD Handbook:

https://www.freebsd.org/doc/handbook/boot-introduction.html

In case of more severe errors, booting from external media (USB
stick or CD), then mounting the required partition and changing
the file should work as well.


-- 
Polytropon
Magdeburg, Germany
Happy FreeBSD user since 4.0
Andra moi ennepe, Mousa, ...