If you run the sudo rpi-update you get:
sudo rpi-update
patchbox@patchbox:~ $ sudo rpi-update
*** Raspberry Pi firmware updater by Hexxeh, enhanced by AndrewS and Dom
*** Performing self-update
*** Relaunching after update
*** Raspberry Pi firmware updater by Hexxeh, enhanced by AndrewS and Dom
FW_REV:a31776f0abb4bee5b79a3334bf748c99a813c084
BOOTLOADER_REV:11c64e3721d104319d8b0f18b675d9beb4eb7f30
*** We're running for the first time
*** Backing up files (this will take a few minutes)
*** Backing up firmware
*** Backing up modules 6.1.0-rpi7-rpi-2712
WANT_32BIT:0 WANT_64BIT:1 WANT_PI4:1 WANT_PI5:1
##############################################################
WARNING: This update bumps to rpi-6.6.y linux tree
See: https://forums.raspberrypi.com/viewtopic.php?p=2191175
'rpi-update' should only be used if there is a specific
reason to do so - for example, a request by a Raspberry Pi
engineer or if you want to help the testing effort
and are comfortable with restoring if there are regressions.
DO NOT use 'rpi-update' as part of a regular update process.
##############################################################
Would you like to proceed? (y/N)
Downloading bootloader tools
Downloading bootloader images
*** Downloading specific firmware revision (this will take a few minutes)
% Total % Received % Xferd Average Speed Time Time Time Current
Dload Upload Total Spent Left Speed
0 0 0 0 0 0 0 0 --:--:-- --:--:-- --:--:-- 0
100 142M 100 142M 0 0 2750k 0 0:00:52 0:00:52 --:--:-- 3019k
BOOTLOADER: up to date
CURRENT: Fri 16 Feb 15:28:41 UTC 2024 (1708097321)
LATEST: Fri 16 Feb 15:28:41 UTC 2024 (1708097321)
RELEASE: latest (/lib/firmware/raspberrypi/bootloader-2712/latest)
Use raspi-config to change the release.
*** Updating firmware
*** Updating kernel modules
*** depmod 6.6.18-v8+
*** depmod 6.6.18-v8-16k+
*** Updating VideoCore libraries
*** Running ldconfig
*** Storing current firmware revision
*** Deleting downloaded files
*** Syncing changes to disk
*** If no errors appeared, your firmware was successfully updated to a31776f0abb4bee5b79a3334bf748c99a813c084
*** A reboot is needed to activate the new firmware