Archive for October 4th, 2014

Booting from SD Card on a X230

The SD Card slot is unfortunately on the PCI bus, so it doesn’t show up as a bootable device.

Solution:

Have a /boot partition on an internal drive, point that at the SD card. Reclaimed ~900MB from Lenovo’s system restore partition to make a /boot partition. GRUB was added to the internal drive.

As suggested in ubuntuforums.org/showthread.php?t=986126&page=3&p=11915401#post11915401, edit the initram image to get SD card support added. In Fedora, this was done using dracut’s kernel modules option in /etc/dracut.conf, so any kernel updates would automatically get the appropriate modules added.

Sticking point – Fedora 17 seemed to have the drivers installed natively. Fedora 20 didn’t, systemd would die.

Main issue was naively assuming that grub was using the correct initramfs that was built. I installed Fedora, then did a yum update kernel to generate the initramfs image. But that didn’t work, so I tried various other things, not realising that the bugged initramfs image was still there, and because it was newer, GRUB was automatically using that instead of the initramfs that I was testing.

Other issue was selinux – the context of files no longer matched (oddly enough). Not sure how/why this happened, but it ended up that I couldn’t log in – GDM login screen never came up, and logging into a console just dumped me right back to the blank console login. Had to boot into single user mode (append “single” to the kernel boot line in grub) and found out it was selinux issues when I got avc denial errors about /bin/sh not having permissions to execute. set enforce=0 fixed this.

cd /run/media/liveuser/ba7fca87-462e-4e8e-91bc-494f352f5293/
mount -o bind /dev dev
mount -o bind /sys sys
mount -o bind /proc proc
mount -o bind /tmp tmp
mount -o bind /run/media/liveuser/b887b758-1bed-48f9-9ee9-4c78af34b487 boot (the bootable drive)
chroot
vi /etc/dracut.conf
cd /boot
dracut initramfs-3.11.10-301.fc20.x86_64.img `uname -r` --force

superuser.com/a/368640/35094 appears to suggest that I could boot grub on the internal drive and hand off control to the grub on the SD Card, which means that I can get SD Cards for different distros and not have to worry about keeping copies of the various vmlinuz/initramfses on the hard drive /boot. Which would be the ideal situation.

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