Booting from Custom Tiny Core Linux for Read Only Filesystem (SED PBA) Notes

custom_tiny_core_read_only_notes.sh

# references
# https://fabianstumpf.de/articles/tinycore_images.htm
# https://gist.github.com/dankrause/2a9ed5ed30fa7f9aaaa2
# https://github.com/Drive-Trust-Alliance/sedutil/wiki/Encrypting-your-drive

# follow these steps on Ubuntu
sudo su
qemu-img create core-image.img 120M -f raw
modprobe nbd max_part=8 && sleep 2 && qemu-nbd -c /dev/nbd0 core-image.img -f raw

fdisk /dev/nbd0
# delete all partitions with d
# hit n and Enter to create a new partition on the disk
# choose p for a primary partition and 1 for the partition number
# accept the default for the last sector of the partition to have it span the rest of the disk
# make the new partition bootable by hitting a and Enter
# hit w and Enter to write the changes to the block device

mkfs.fat /dev/nbd0p1 -n COREGRUB
# mount /dev/nbd0p1 at /media/username/COREGRUB, from Ubuntu Disks GUI
sudo grub-install --boot-directory=/media/username/COREGRUB/boot /dev/nbd0

nano /media/username/COREGRUB/boot/grub/grub.cfg

# paste grub config:

set timeout=1
set default=0

menuentry "Tinycore ISO" {
 loopback loop /tinycore.iso
 linux (loop)/boot/vmlinuz tinycore cde iso=LABEL="COREGRUB" libata.allow_tpm=1 loglevel=3 --
 initrd (loop)/boot/core.gz
}

# save grub config contents and close nano
# copy a custom tinycore.iso to /media/username/COREGRUB
umount /dev/nbd0p1
qemu-nbd -d /dev/nbd0
# test
qemu-system-i386 core-image.img
# if it works then flash it to the Shadow MBR from sedutil rescue image: https://github.com/Drive-Trust-Alliance/sedutil/wiki/Executable-Distributions