DOKK / manpages / debian 11 / flash-kernel / flash-kernel.8.en
FLASH-KERNEL(8) System Manager's Manual FLASH-KERNEL(8)

flash-kernel - put kernel and initramfs in boot location

flash-kernel [--supported] [--force] [kvers]

flash-kernel is a script which will put the kernel and initramfs in the boot location of embedded devices that don't load the kernel and initramfs directly from /boot. flash-kernel supports devices that boot from flash memory (hence the name) as well as some devices that require a special boot image on the disk.

Optionally, it can be passed a version of the kernel to flash; only the highest version will be flashed and other versions will be ignored unless the --force option is used. Kernel and initrd are read from /boot.

Note that when the --force the kernel can be overwritten with the current version whenever a package is installed which changes the kernel, initramfs etc. Therefore this is only really useful for one-off testing.

Prior to flashing the kernel, a check is performed to verify that the subarchitectures of the machine and the image to be flashed match. Valid filenames for images to flash are suffixed with the subarchitecture.

If the --supported option is used, flash-kernel will test to see if the hardware is supported, and return a true or false value.

Specify a specific machine, overriding the autodetection, also see the description of /etc/flash-kernel/machine below. Can be set to `none' to disable flash-kernel. This can be used when installing flash-kernel into a chroot, for example while preparing a filesystem image. WARNING: Take great care when running flash-kernel in a chroot, since the choice of machine may cause host filesystem partitions to be mounted and modified.

The database of machines which flash-kernel knows about. See /usr/share/doc/flash-kernel/README.gz For information on the database fields.
Local overrides to the database of machines
If present this can be used to override the machine autodetection. The contents must be a string which matches an entry in the database. Or `none' to disable flash-kernel.

Martin Michlmayr <>