Currently it is an optional (non-mandatory) PS3 update, and below is what Sony stated in their Tweet on the revision, to quote:
"PS3 system software update 4.21 will be released soon. It's a minor, optional update that improves software stability."
As always, we will update this post as more details are available!
From Sony's page: Find out what features are included in PS3 system software update 4.21.
An update to the PS3 system software was released on 5 July 2012. If you update your PS3 system, the system software version will be 4.21 and the following features will be updated.
In order to download PS3 system software version 4.21, you will need a minimum 200MB of free space on either the PS3 Hard Disk Drive (System Update) or on removable storage media (PC Update).
Main features in system software update version 4.21
System stability during use of some PS3 software has been improved.
Finally, from zadow28: LV1 Dump for PS3 FW 4.21 released! Now this wasn't easy, but after some days I managed to dump the lv2. I have managed to dump the lv1 also, and that is more important. Made two links since this isn't something sony likes. Regards.
Here is the lv2_dump from 4.21 (linked above). Sycall table was found at offset 0x346390.
No its not for patching the kernel, but it would help getting there. This is an dump from the kernel and lv2 functions. So in an way its the lv2 kernel decrypted.remember the one we cant decrypt yet.
Together with the sycall table you would now see where the correct syscalls would be on ofw 4.21. Therefore exploiting it. Also here (above) is an lv2 dumper for cfw 4.21 i converted.. usb in the right slot. regards to the orgiginal creator. not sure who it is.
Well it looks like Sony is really trying to stick it to CFW users again! WOW 4.21 really??? Come on we just had the 4.20 update not even a few weeks ago!
Give it up sony you can't beat the hackers there will always be a way to hack your precious ps3 system that you dummies said that couldn't be hacked!!!! Looks like there will be a new revision of fckpsn! Long live cfw, long live fckpsn!!
Just checked to see if fckpsn is working and its still letting me sign into PSN!!! So if they where trying to stop this hack from working its clearly not working out for them! This doesn't mean though that this hack is going to work forever though they still might not of released the update yet to the systems I will keep checking on this throughout the day and keep everyone posted!!!
Last edited by Starchild2k; 07-05-2012 at 04:36 AMReason: Automerged Doublepost
okay in order to deactivate the rebug 4.11 spoofer you must use CEX DEX to deactivate the spoofer. Once your in CEX DEX you must switch the system back to RETAIL (L1+X) Restart the system and the system will show 3.55 again in the System Information. Also if you plan on using PSON on rebug 3.55.2 DON'T!!!
It will cause the system to have a RSOD (RED SCREEN OF DEATH) which in this case you would have to relaod the CFW in Recovery Mode to fix the RSOD. If you plan on using fckpsn on REBUG 3.55.2 then you must first use DEV BLIND to get dev_flash access so you can replace the CA27.cer with the fckpsn CA27.cer.
If you do go this route you wont have to switch from REBUG 3.55.2 to kmeaw 3.55. the only reason you would need to switch from rebug 3.55.2 to kmeaw 3.55 is if you planned on using PSoN. I hope this helps you out and good luck and if there is any more questions feel free to ask and I will help you out as much as I can!