[gentoo-user] Re: Kernel did not finding root partition

[Kai Krakow]

Am Tue, 30 May 2017 09:26:03 +0100
schrieb Peter Humphrey <peter@××××××××××××.uk>:

> On Monday 29 May 2017 21:42:28 Kai Krakow wrote:
> > Am Mon, 29 May 2017 19:16:11 +0100
> >
> > schrieb Neil Bothwick <neil@××××××××××.uk>:
> > > On Mon, 29 May 2017 15:07:48 -0300, Raphael MD wrote:
> [...]
>  [...]
> > >
> > > You said you were using rEFInd, why have you got GRUB as well.
> > > rEFInd can work without a config, GRUB cannot.
> >
> > This puzzles me, too... Maybe rEFInd was installed to sda and grub
> > installed to sda1, so rEFInd would chain-boot through grub.
> >
> > Grub, however, won't work without a config file. I'd also suggest to
> > skip grub completely and use just one loader.
>
> Not only that, but for some reason I couldn't get grub to work at all
> on my Asus UEFI system. I use systemd-boot only, with a separate
> config file for each kernel I might want to boot. (I do not have the
> rest of systemd in this openrc system; just its boot program.)
>
> It might not help the OP but this is my script for compiling a kernel:
>
> # cat /usr/local/bin/kmake
> #!/bin/bash
> mount /boot
> cd /usr/src/linux
> time (make -j12 && make modules_install && make install &&\
> 	/bin/ls -lh --color=auto /boot &&\
> 	echo &&\
> 	cp -v ./arch/x86/boot/bzImage /boot/EFI/Boot/bootX64.efi
> ) &&\
> echo; echo "Rebuilding modules..."; echo &&\
> emerge --jobs --load-average=48 @module-rebuild @x11-module-rebuild
>
> He may be missing the copying step; that would explain his inability
> either to boot or to supply the info you asked him for.

I hooked into the install hook infrastructure of the kernel instead:

$ cat /etc/kernel/postinst.d/70_rebuild-modules
#!/bin/bash
exec env -i PATH=$PATH /usr/bin/emerge -1v --usepkg=n @module-rebuild

$ cat /etc/kernel/postinst.d/90_systemd
#!/bin/bash
/usr/bin/kernel-install remove $1 $2
/usr/bin/kernel-install add $1 $2

This takes care of everything and the kernel-install script from
systemd also rebuilds the dracut initrd (because it installed hooks
to /usr/lib/kernel/install.d).

eclean-kernel can then be used to properly clean up obsolete kernel
versions. I'm running it through cron to keep only the most recent 5
kernels at weekly intervals.

For the hooks to properly execute at the right time, it is important to
give the "make install" target last:

$ cd /usr/src/linux
$ make oldconfig
# make -j9 
# make modules_install firmware_install install

The "install" target triggers the hooks, so modules have to be already
installed at that time.

Additionally I have a script to rebuild dracut easily on demand (e.g.,
when early boot components were updated or changed):

$ cat /usr/local/sbin/rebuild-dracut.sh
#!/bin/bash
set -e
if [ "$1" == "-a" ]; then
        versions=$(cd /boot && ls vmlinuz-* | fgrep -v .old | sed 's/vmlinuz-//')
else
        versions="$@"
fi
versions=${versions:=$(uname -r)}
for hook in $(ls /etc/kernel/postinst.d/*_{dracut,grub,systemd} 2>/dev/null); do
        for version in $versions; do
                ${hook} ${version%.old} /boot/vmlinuz-${version}
        done
done


-- 
Regards,
Kai

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