To install the firmware from a USB drive, the PS3 requires a very specific folder structure. If the folders aren't named correctly, the console will report that "no applicable update data was found". How to download PS3 Firmware for RPCS3 Emulation
Notably, firmware 3.21 used the PUP system to remove the "OtherOS" feature entirely, citing security concerns, which led to a class-action lawsuit against Sony. Legacy and Modern Context firmware ps3updatpup
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If your console’s software becomes corrupted (the dreaded "Black Screen of Death" or "Looping Update"), reinstalling the firmware via Safe Mode is often the only fix. How to Properly Use PS3UPDAT.PUP To install the firmware from a USB drive,
But if you’re looking for a on updating your PS3’s official firmware using PS3UPDAT.PUP — for example, updating via USB when the network update fails — I can absolutely help with that. Legacy and Modern Context But something was wrong
This group seeks modified PUPs created by the homebrew community (e.g., Evilnat, Rebug, Ferrox, Cobra). A CFW PUP: