The Stable update OS2.0.4.0.VLACNXM has been officially released for Xiaomi 12S Ultra (codename is thor). Before updating, please make sure you have downloaded the exact ROM matching your Xiaomi phone/tablet. In Fastboot mode, you can check model code by typing fastboot getvar product in cmd/shell.
The firmware files posted here are all official Xiaomi MIUI or HyperOS ROM, xiaomiROM.com do not own and never modified those firmwares，you will always download the file from Xiaomi server.
You may interest in those contents: Xiaomi 12S Ultra ROM Topics Xiaomi Devices Index
Download Xiaomi 12s ultra (thor) China HyperOS OS2.0.4.0.VLACNXM Recovery ROM with Android 15.0. Firmware size is 6.8 GB.
Download Xiaomi 12s ultra (thor) China HyperOS OS2.0.4.0.VLACNXM Fastboot ROM with Android 15.0. Firmware size is 8.4 GB.