LakersDroid
Android Expert
Just curious. And why is it only upgradable and not downgradeable with S-off like the hboots, radio, etc.
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Root What exactly does the PRI do?
- Thread starter LakersDroid
- Start date
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- Tags
- htc evo v 4g
ramjet73
Android Expert
I have searched a number of times trying to find a clear explanation of exactly what the "PRI" firmware represents or why it cannot be downgraded even with S-OFF, but have yet to find a clear explanation. Some people have claimed it stands for "Primary Rate Interface" which is a telephony term for an ISDN service that combines voice and data on the same connection, in a similar fashion to DSL. That sounds like a feasible explanation since our cell phones do that but I've never been able to find it officially documented anywhere.
What I have found are a number of references that say the PRI and radio firmware should be upgraded together since they depend heavily on each other and are tested together at a given firmware level. The VM OTA update contains both PRI (rcdata.img) and radio (radio.img) firmware which is why I highly recommend using that version at this point rather than the ones in the original "fix everything" thread that come from two different versions (baseband levels) of Sprint GB firmware.
ramjet73
ron scubadiver
Android Enthusiast
ramjet, I am inclined to agree with you on the OTA's. Probably, the fix everything thread should be updated to reflect this. Anyone who buys an EVO V 4G now can update before rooting and consider skipping that procedure even if they S_Off.
HaTrEd360
Android Expert
I see you are able to downgrade PRI, but it won't actually show the older version in the About Phone settings. The way I've seen ppl do it is by fooling the current installed PRI into thinking you're either patching it or updating it as it will stay the current number. So even tho they'd be actually downgrading it, the older version can be branded as the current version. Hence why ppl complained in the fix everything thread that they noticed the PRI didn't actually change in the About Phone section of settings. 