Currently I am using the "boot-directdisk" bbclass to create a raw image for an x86 based system. My target system does not have EFI support which means that syslinux is used. I am using the boot-directdisk because this allows me to "install" the image using wget -O/dd on the compact flash card before assembling the unit.

The issue with this approach is that currently I am unable to upgrade the kernel image (which results in still shipping a kernel with many known security issues). By default the kernel recipe will use update-alternatives to create/update a symlink to point to the new kernel image. If I update the kernel package the installed kernel and the modules will not match.

My proposal would be to use another boot loader. I asked about grub but Darren Hart pointed me to extlinux. In case of extlinux I could do one of the following:

I could either have a dedicated /boot partition for extlinux or include it directly in my system.