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<title>1.4. Prepare Reboot</title>
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<h1>1.4. Prepare for Reboot</h1>
<p>Follow this instructions with active chroot,
first <a href="configure.html#chroot">mount partitions</a>
and before chroot mount follow file systems;</p>
<pre>
$ sudo mount --bind /dev $CHROOT/dev
$ sudo mount -vt devpts devpts $CHROOT/dev/pts
$ sudo mount -vt tmpfs shm $CHROOT/dev/shm
$ sudo mount -vt proc proc $CHROOT/proc
$ sudo mount -vt sysfs sysfs $CHROOT/sys
</pre>
<p>Now you can chroot;</p>
<pre>
$ sudo chroot $CHROOT /usr/bin/env -i \
HOME=/root TERM="$TERM" PS1='\u:\w\$ ' \
PATH=/bin:/usr/bin:/sbin:/usr/sbin \
/bin/bash --login
</pre>
<h2 id="linux">1.4.1. Port kernel</h2>
<p>Core ports have two
<a href="linux.html">linux kernels</a>,
<a href="ports/linux-libre">linux-libre</a> and
<a href="ports/linux-blob">linux-blob</a>.
Port linux-libre kernel is a true source based kernel that
respects your freedoms, is x86_64 but not generic configured,
select modules (drivers) for your hardware, for example
correct graphic driver and disk. Port linux-blob is dangerous,
contain blobs (from bad corporations).</p>
<p>Both ports apply grsecurity patch and are configured in
a way that break building some packages and have performance
impact in building process. Solution is to have several kernels,
production, testing, debug with one of them without grsecurity.</p>
<pre>
# cd /usr/ports/c9-ports/linux-libre
# pkgmk -d
# pkgadd /usr/ports/packages/linux-libre#4.9.11-2.pkg.tar.gz
</pre>
<h2 id="grub">1.4.3. Configuring Grub2</h2>
<p>Create grub file in /etc/default/grub with values;</p>
<pre>
GRUB_DISABLE_LINUX_UUID=false
GRUB_ENABLE_LINUX_LABEL=false
</pre>
<p><a href="http://www.gnu.org/software/grub/manual/grub.html">Grub Manual</a>,
install grub on MBR of disk sdb;</p>
<pre>
# grub-install /dev/sdb
Installation finished. No error reported.
</pre>
<p>If you are installing on removable media;</p>
<pre>
# grub-install --removable /dev/sdb
Installation finished. No error reported.
</pre>
<p>grub-mkconfig generates grub.cfg, it will try to discover
available kernels and attempt to generate menu entries for
them;</p>
<pre>
# grub-mkconfig -o /boot/grub/grub.cfg
Generating grub.cfg ...
Found linux image: /boot/vmlinuz-4.1.30-crux
Found initrd image: /boot/initramfs-4.1.30-crux.img
done
#
</pre>
<p>Check /boot/grub/grub.cfg, if is wrong add menu to
/etc/grub.d/40_custom, replace correct partition from grub-prob
output and correct UUID from fstab or blkid</p>
<pre>
# grub-probe --target=hints_string /
</pre>
<h3>1.4.3.1. Rescue iso</h3>
<p>Simple way to have "resque" system is to mount boot as read only,
this assures that even as root nothing can be changed without remount.
To have different system independent from host grub will have entry to
boot small iso on /boot partition;</p>
<p>Crux iso is not used because at the moment it fails to
find "crux-media" during or after init.</p>
<pre>
$ wget http://ftp.nluug.nl/os/Linux/distr/tinycorelinux/7.x/x86/release/CorePlus-current.iso
$ sudo mv CorePlus-current.iso /boot/tinycore.iso
</pre>
<p>Edit /etc/grub.d/40_custom</p>
<pre>
menuentry "Rescue" {
load_video
set gfxpayload=keep
set isofile="/tinycore.iso"
loopback loop $isofile
linux (loop)/boot/vmlinuz64 loglevel=3 cde
initrd (loop)/boot/corepure64.gz
}
<h2 id="checkup">1.4.4. Checkup</h2>
<p>If you have qemu installed you can see if it boots, in this
example sdb is usb external drive;</p>
<pre>
# qemu-system-x86_64 -kernel /boot/vmlinuz-linux -initrd /boot/initramfs-linux.img -append root=/dev/sdb /dev/sdb2
</pre>
<h3>Debug Grub</h3>
<h3>Debug initram</h3>
<pre>
/usr/lib/dracut/skipcpio /boot/initramfs-4.9.11-blob.img | gunzip -c | cpio -i -d
36875 blocks
</pre>
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<p>This is part of the c9-doc Manual.
Copyright (C) 2017
c9 team.
See the file <a href="../fdl-1.3-standalone.html">Gnu Free Documentation License</a>
for copying conditions.</p>
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