mfsroot starts sysinstall how?
devin.teske at fisglobal.com
Wed Dec 12 18:22:43 UTC 2012
On Dec 12, 2012, at 7:50 AM, Rick Miller wrote:
> On Wed, Dec 12, 2012 at 10:44 AM, Rick Miller <vmiller at hostileadmin.com> wrote:
>> Hi All,
>> How is sysinstall invoked in a FreeBSD 8.x mfsroot.gz?
It's actually invoked in the place of init(8).
> To explain more, I would like to boot into a shell as opposed to
> sysinstall. safe mode and single user don't seem to.
Safe mode and single user won't work because sysinstall is acting as init and it doesn't implement those functions.
To run a shell script in the place of init(8), you have to do some bootstrapping.
Enter DruidBSD ( … not to be confused with previously discussed Druid [in another thread]).
DruidBSD is a ~24MB ISO (~32MB if you get the version that has the extra tools like memtest86, etc.):
Not only does it do what you're asking about … boot to a shell … but you can customize it.
It uses the same build framework as the Druid (requiring GNU make, mkisofs, and [optionally] perl -- only required if you want the ISO to work from both CD/DVD _and_ USB thumb drive). You can download the source code, make changes to the custom /etc/rc which does the bootstrapping for you, and more -- then when finished, simply say "gmake freebsd" to produce your new custom media.
It doesn't stop there… the /etc/rc that's in the mfsroot (link below):
Is designed to bust you out of the mfsroot and bootstrap you not into a derelict sh(1) prompt, but instead a [more] usable bash(1) prompt complete with hundreds of extra utilities.
PRO TIP: The Druid (which is the [much] larger ~500MB FreeBSD Installer that uses the same build framework) actually has a miniature version of DruidBSD tucked into its boot loader. That is to explain that when you use the FreeBSD Druid installer, the beastie boot menu has a fancy feature where you can select a different mfsroot from the menu (if you select the "rescue_mfsroot" then you're essentially invoking a custom version of DruidBSD, which we're talking about right now w/respect to replacing sysinstall(8) in an mfsroot with a bootstrap-to-interactive-shell).
The information contained in this message is proprietary and/or confidential. If you are not the intended recipient, please: (i) delete the message and all copies; (ii) do not disclose, distribute or use the message in any manner; and (iii) notify the sender immediately. In addition, please be aware that any message addressed to our domain is subject to archiving and review by persons other than the intended recipient. Thank you.
More information about the freebsd-questions