This will allow you to take your SD card and use it with different versions of Pi.
At the moment I have a Pi3B+ and the SD card has 4 kernel revisions, 4.19.88+, 4.19.88-v7+, 4.19.88-v7l+ and 4.19.88-v8+, installed. This will allow me to use the same SD card on any different version of the Pi, Pi A, Pi B, Pi A+, Pi B+, Pi Zero, Pi Zero W, Pi 2B, Pi 3B, Pi 3B+ or Pi 4B.
Pi A, Pi B, Pi A+, Pi B+, Pi Zero, Pi Zero W will use kernel 4.19.88+. Pi 2B, Pi 3B, Pi 3B+ will use kernel 4.19.88-v7+. Pi 4 will use kernel 4.19.88-v7l+ and Pi 4 in 64 bit mode will use kernel 4.19.88-v8+.
However, if you have to install the wifi driver for your wifi module, if you change to a different Pi using a different kernel revision you will need to install the driver for that particular kernel revision if you have not already done it.
If you use the command
Code: Select all
Code: Select all
pi@raspberrypi:~ $ ls /boot bcm2708-rpi-b.dtb bcm2709-rpi-2-b.dtb bcm2711-rpi-4-b.dtb fixup4cd.dat fixup.dat kernel7l.img start4cd.elf start_db.elf bcm2708-rpi-b-plus.dtb bcm2710-rpi-2-b.dtb bootcode.bin fixup4.dat fixup_db.dat kernel8.img start4db.elf start.elf bcm2708-rpi-cm.dtb bcm2710-rpi-3-b.dtb cmdline.txt fixup4db.dat fixup_x.dat kernel.img start4.elf start_x.elf bcm2708-rpi-zero.dtb bcm2710-rpi-3-b-plus.dtb config.txt fixup4x.dat issue.txt LICENCE.broadcom start4x.elf bcm2708-rpi-zero-w.dtb bcm2710-rpi-cm3.dtb COPYING.linux fixup_cd.dat kernel7.img overlays start_cd.elf
Also using the command ls /lib/modules will show a set of module directories each used by one of the different kernel versions from the ls /boot command.
If you use your SD card on one version of the Pi and have installed a wifi driver for that Pi and then you move the SD card to a different Pi which uses a different kernel version you will need to install the wifi driver for the different kernel version used by the different Pi.
I hope this explains how the SD card can be used with different versions of the Pi and why you may need to reinstall the wifi driver if you move it to a different Pi using a different kernel version.