If a user’s Vita is in a bootloop or has a corrupt system update, the system can be restored by placing this file in ux0:data/PSP2/UPDATE/PSP2UPDAT.PUP and running a system update in Safe Mode.
I can provide the specific steps or the correct PSP2UPDAT.PUP for your situation. PSPUPDAT.PUP disappears · Issue #11 - GitHub
psp2updat.pup is a critical system file for the PlayStation Vita ecosystem. While it appears as a simple archive, it is a fortified container that controls the evolution and security of the Vita hardware. For Sony, it was a tool for security maintenance; for the hacking community, it is a puzzle to be solved to enable homebrew and custom firmware.
is the official filename for the PlayStation Vita’s firmware update package. The naming convention breaks down as follows: