Whether you’re using Raspberry Pi OS or another distribution (e.g. Ubuntu), the rpi-eeprom-update tool is likely available, and in the case of Raspberry Pi OS will update the firmware of the Pi automatically.
However, on Ubuntu the rpi-eeprom package tends to lag behind a little (or a lot, if you’re using an LTS release). As an example, the latest firmware for an RPi4B packaged in the 24.04 LTS is from May 2023, with the default release channel sticking with a build from January 2023.
If you’d like to stay a bit more up-to-date than this, it’s easy to manually update the firmware of the Pi though. Raspberry Pi host the firmware on GitHub, so you just need to pick the appropriate release for your hardware (-2711 being for RPi4B, and -2712 being for RPi5B), and the desired release channel - either default, or latest if you’re after the cutting edge. All you then need do is download, schedule the update, and reboot:
wget https://github.com/raspberrypi/rpi-eeprom/raw/refs/heads/master/firmware-2712/default/pieeprom-2024-11-12.bin
sudo rpi-eeprom-update -f pieeprom-2024-11-12.bin
sudo reboot now
Once rebooted, you can check that the new firmware flashed OK by just running rpi-eeprom-update:
BOOTLOADER: up to date
CURRENT: Tue Nov 12 16:10:44 UTC 2024 (1731427844)
LATEST: Wed Dec 6 18:29:25 UTC 2023 (1701887365)
RELEASE: default (/lib/firmware/raspberrypi/bootloader-2712/default)
Use raspi-config to change the release.
Here, LATEST refers to the latest firmware that’s been packaged in rpi-eeprom and unpacked to /lib/firmware/raspberrypi/, rather than the latest available from Raspberry Pi directly. Note that on Ubuntu, the mentioned raspi-config tool is not available; instead, the /etc/default/rpi-eeprom-update file can be used to configure which release channel to use if you are content with sticking to packaged firmwares.