# Sticky for Prom units?



## sbn (Aug 30, 2007)

I was wondering, wouldn't it be a good idea to have a sticky for units that have Proms which prevent any modifications? A separate one. It is not apparent when coming to this forum that not all Tivo units can be easily modified. In fact as I understand most newer models with the Prom will prevent the average Joe from delving into additional software.


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## mrmike (May 2, 2001)

Forms of hackery which require prom changes are verboten discussion here (AFAIK), so that might not fit with the ruleset.


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## tivoupgrade (Sep 27, 2000)

mrmike said:


> Forms of hackery which require prom changes are verboten discussion here (AFAIK), so that might not fit with the ruleset.


I could certainly be wrong, but I don't think that is the case, unless the discussion is related to extraction of video content. There is nothing specific that I could find in the rules, or any of the sticky posts, that mentions this.

Not sure that a sticky is warranted as PROM mods aren't widely used and are also not accessible to the average Joe, but I'm sure if the discussion *shouldn't* happen, a mod will jump in and set the record straight.


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## classicsat (Feb 18, 2004)

There is a thread on which models need a PROM mod, and which do not.

In short, those a TSN beginning with 5 or 6 (or likely higher), and probably the TGC unit (which the S2DT is related to), require a PROM mod.


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## mr.unnatural (Feb 2, 2006)

mrmike said:


> Forms of hackery which require prom changes are verboten discussion here (AFAIK), so that might not fit with the ruleset.


Not true. Any hacks, including ones that are permitted, require a PROM mod on any series 2.5 or series 3 Tivo before they can be implemented. Discussion of PROM mods is well within the bounds of this forum's rules.


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## mrmike (May 2, 2001)

mr.unnatural said:


> Not true. Any hacks, including ones that are permitted, require a PROM mod on any series 2.5 or series 3 Tivo before they can be implemented. Discussion of PROM mods is well within the bounds of this forum's rules.


I thought all PROM mods were by their very nature a modification that was counter to TiVo's terms of service. I'd be happy to be disabused of this notion.


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## tivoupgrade (Sep 27, 2000)

mrmike said:


> I thought all PROM mods were by their very nature a modification that was counter to TiVo's terms of service. I'd be happy to be disabused of this notion.


That is possible; I will look into that - but that does not necessarily mean that the discussion is not permitted hear. Theft of service and content is not permitted, but making mods to your TiVo (in general) is not).


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## classicsat (Feb 18, 2004)

We discuss lots of things that are technically violations of TiVos Terms Of Service. 

Just a few subjects are forbidden to one degree to another, such as extraction, and theft of service (either TiVos or using TiVo to aid in stealing pay TV services, or with stolen Pay TV).


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## mr.unnatural (Feb 2, 2006)

The PROM mod by itself has no effect on the operation of the Tivo and does not circumvent anything. It's only when you start installing files that weren't part of the original OS that the magic starts to happen. The Tivo checks to see if anything has changed in the basic configuration since the lat time it booted up. If it sees something that doesn't belong, it simply deletes the offending files. The PROM mod prevents this check from occurring and thereby breaks the chain of trust. However, if nothing else has been done to the Tivo to invoke this check, no harm has been done. OTOH, implementing a PROM mod just configures the Tivo to behave just like the predecessor models.

The extra security measures have been put into place to keep the studios happy and also keep Tivo out of hot water due to any legal issues. Tivo has always responded to hacks that have circumvented the chain of trust by implementing tighter measures in subsequent models. They've done their part to appease the studios but they also have no control over what the hacking community comes up with to defeat their security measures. I doubt that Tivo really cares about a hack that 99&#37; of Tivo owners would never bother to implement due to its complexity. It's the studios that may take exception to it, but only if it's used for extracting digital content (hence the ban on the topic here). Since the only hack that would cause any problems with the studios is not permitted for discussion here then there should be no repercussions about discussing the same hacks on a unit that requires a PROM mod as one that can be hacked with killhdinitrd or other software mod.


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## BTUx9 (Nov 13, 2003)

Just to clarify a few points:


mr.unnatural said:


> The Tivo checks to see if anything has changed in the basic configuration since the lat time it booted up.


umm... no. the checks it performs have nothing to do with the state at last boot.


mr.unnatural said:


> If it sees something that doesn't belong, it simply deletes the offending files. The PROM mod prevents this check from occurring and thereby breaks the chain of trust.


no, the prom mod prevents the check on the kernel/initrd. It's initrd that actually checks files against internal hashes and deletes them if they fail.


mr.unnatural said:


> OTOH, implementing a PROM mod just configures the Tivo to behave just like the predecessor models.


again, no. previous models DID check the integrity of the kernel, but didn't check the load params for it. Since killhdinitrd bypasses initrd by changing the load params. those checks in newer proms effectively neutralized it.


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## mr.unnatural (Feb 2, 2006)

I stand corrected. You're absolutely correct about the checks having nothing to do with the state of the last boot. I also left out the part about initrd performing the actual check so thanks for setting that straight. I've been having far too many senior moments of late and I hadn't thought about the initrd process for a while so my brain was a bit rusty on the topic. The basic point I was trying to make is that the PROM mod is essentially invisible to the user and won't affect normal operation of the Tivo.


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## h0mi (Dec 29, 2007)

Am I correct in asking if Promming is required to upgrade the internal HDD on the tivo HD?


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## T1V0 (Jun 14, 2006)

h0mi said:


> Am I correct in asking if Promming is required to upgrade the internal HDD on the tivo HD?


no. a prom hack is not a prerequisite for a capacity upgrade on any tivo.


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