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Any chance JMFS will work on a Roamio?

6K views 28 replies 13 participants last post by  c-collins 
#1 ·
Planning on getting a Roamio. If current tools work might I will get a plus and upgrade it myself to 4 or 5 Terabytes. Otherwise I would go for the pro and probably still end up upgrading it.

Anyone care to speculate?
 
#2 ·
It would be pure speculation at this early stage :)
But, we do know that something has changed, as the Premiere maxed out at 2TB drives, so at minimal changes would need to be made to the tools to support what ever new partition layout, or new file system or magic was used. Couple that with minor changes to recognize the new platform and it's shipping disks.

Of course it is also possible that Tivo has locked things down, and drive upgrades will not be possible. This was the case for a while with the Premieres.

If you need more that 1TB anytime in the next 6 months, and want a new Tivo now, go big, go Pro. If you can wait a little, then wait a week or so till some smart folks pop the box open and see what works. The changes might be simple, they might not be.
 
#6 ·
Tivo has a long track record of finding ways to prevent upgrades using existing tools as well as new ways to thwart hackers with each new platform. Chances are good this won't be any different.
Or new designs for better performance just make old upgrade tool not work, I do not think TiVo is spending time to prevent hard drives upgrades, all TiVo would have to do is on the initial setup put the hard drive SN into flash and look for that SN on boot, that would end hard drive upgrades for TiVos.
 
#8 ·
Or new designs for better performance just make old upgrade tool not work, I do not think TiVo is spending time to prevent hard drives upgrades, all TiVo would have to do is on the initial setup put the hard drive SN into flash and look for that SN on boot, that would end hard drive upgrades for TiVos.
If they did that then we'd be looking at an EEPROM hack just to upgrade the drive. I can't see Tivo doing that because it would cause them too much grief to refurbish Tivos for resale or as a warranty replacement.

I wasn't trying to imply that Tivo was purposely trying to prevent us from upgrading drives. It just tends to turn out that way. As for performance improvements, it's more like adding useless features with little or no improvement to the overall functionality. Tivos have certainly come a long way since the early days, but they'd probably still be mired in the original OS if it weren't for competition from DirecTV, Dish, and the cablecos.
 
#9 ·
My speculation is a definite maybe. The APM of the 4 tuner units has been modified ever so slightly. I assumed it was in preparation for larger hard drives. JMFS works with those units. If I can see the APM of a Roamio, then that would help me confirm my assumption (and also perhaps provide a way of expanding the 4 tuner units to larger than 2TB.) The kicker would be if the OS JMFS is running off of supports larger than 2TB and if JMFS as written supports larger drives. I, unfortunately, am not a Java programmer so I do not know. If any Java programmers out there can look at JMFS source and see, that would be great.
The only other question is if Tivo changed anything else in their code. When they went from S3 to S4, they changed something that would not allow paired partitions to work. From S3 and earlier units, expansion was done by partition pairs. A MFS app and media partition. With the S4 units, if partitions were added in pairs, the media partition was "deleted." Consequently, the partition pair was coalesced into a single partition which the TiVo liked and we were able to expand. Perhaps TiVo was trying to prevent expansion was the reason for the change. If that is the case, then they might change the code so that any extra partitions that are located on the same drive as the original partitions might be ignored / deleted. In that case, we might be hosed and the only way to expand would be to rewrite the original partitions larger to fill the space available. We won't know any of this until some brave soul is ready to take the plunge and willing to experiment a little. First by using DvrBARS and make a backup of a virgin drive. In the meantime we wait.
 
#10 ·
If they did that then we'd be looking at an EEPROM hack just to upgrade the drive. I can't see Tivo doing that because it would cause them too much grief to refurbish Tivos for resale or as a warranty replacement.
.
To hack any TiVo EEPROM would most likely require some plug in hardware, I sure TiVo will not make it as easy as the BIOS on most computers. But hopefully TiVo did not do this.
 
#11 ·
To hack any TiVo EEPROM would most likely require some plug in hardware, I sure TiVo will not make it as easy as the BIOS on most computers. But hopefully TiVo did not do this.
The problem modifying S4 eeproms is that they are located inside the CPU and not on an external chip. Also the eeproms have a bit set to prevent modifications so you have to replace the CPU with a modified CPU. Not for the faint of heart.

More than likely the Roamio has a similar setup.
 
#12 ·
My speculation is a definite maybe. The APM of the 4 tuner units has been modified ever so slightly. I assumed it was in preparation for larger hard drives. JMFS works with those units. If I can see the APM of a Roamio, then that would help me confirm my assumption (and also perhaps provide a way of expanding the 4 tuner units to larger than 2TB.) The kicker would be if the OS JMFS is running off of supports larger than 2TB and if JMFS as written supports larger drives. I, unfortunately, am not a Java programmer so I do not know. If any Java programmers out there can look at JMFS source and see, that would be great.
The only other question is if Tivo changed anything else in their code. When they went from S3 to S4, they changed something that would not allow paired partitions to work. From S3 and earlier units, expansion was done by partition pairs. A MFS app and media partition. With the S4 units, if partitions were added in pairs, the media partition was "deleted." Consequently, the partition pair was coalesced into a single partition which the TiVo liked and we were able to expand. Perhaps TiVo was trying to prevent expansion was the reason for the change. If that is the case, then they might change the code so that any extra partitions that are located on the same drive as the original partitions might be ignored / deleted. In that case, we might be hosed and the only way to expand would be to rewrite the original partitions larger to fill the space available. We won't know any of this until some brave soul is ready to take the plunge and willing to experiment a little. First by using DvrBARS and make a backup of a virgin drive. In the meantime we wait.
You can't really modify APM to support drives greater than 2 TiB. I suppose you could simply increase the logical block size from 512 bytes to something like 4096. That would increase the upper limit to 16 TiB. But that might also require a native advanced format drive, which are rare.

But Tivo could join the 21st century and do what everyone else on the planet does: put the OS on flash and just put the recordings on the hard drive. Upgrading could then be as simple as plugging in a brand new drive, but you'd lose your previous recordings.

It'd be easy to copy the hard drive to another hard drive of the same size, but when copying to a bigger size I'm not sure how you'd expand it. Could be as simple as using a common partition tool to increase the size of the partition.
 
#13 ·
You can't really modify APM to support drives greater than 2 TB.

But you can do what everyone else on the planet does: put the OS on flash and just put the recordings on the hard drive. Upgrading could then be as simple as plugging in a brand new drive, but you'd lose your previous recordings.

It'd be easy to copy the hard drive to another hard drive of the same size, but I'm not sure how you'd expand it. Could be as simple as using a common partition tool to increase the size of the partition.
Yes and no. The current APM is based on 512 byte blocks. The 4 tuner premieres have code found in a reserved area of each entry in the APM. If that code tells the OS to toggle to 4k blocks, then you can have larger than 2TB drives. Although it is in APM format, nothing forces TiVo to stick to a true APM format.
Common partition tools don't work on TiVos. Even so, expanding the MFS media partition in the APM will not increase the size of it inside the Media File System itself.
 
#14 ·
Well whatever they're doing Weaknees has already figured out the upgrade method...hopefully something is posted here soon...
I agree, it took Weeknees all of one day to start offering upgraded drives. So the changes necessary cannot be too difficult.

Is the guy that put together all of the Premier upgrade tools still around? I cannot remember his username at the moment.
 
#15 ·
I agree, it took Weeknees all of one day to start offering upgraded drives. So the changes necessary cannot be too difficult.

Is the guy that put together all of the Premier upgrade tools still around? I cannot remember his username at the moment.
That would be Comer, who I believe is located in Canada. He's been MIA around here for a long time (unless I missed some posts).

He has a gmail email address that displays on the screen of JMFS as it boots.
 
#20 ·
Now I am wondering what the problem is with drives greater than 3TB and can it be fixed.
The Tivo probably only partitions the first 3 TB of the drive. You could take the drive back out and use gparted to expand the partition, plop it back in, and see if it works.

But it'll take a while to fill up a 4 TB hard drive to see if it truly works, even with 4 tuners. That's probably the test Weakness is running right now.
 
#21 ·
Yes and no. The current APM is based on 512 byte blocks. The 4 tuner premieres have code found in a reserved area of each entry in the APM. If that code tells the OS to toggle to 4k blocks, then you can have larger than 2TB drives. Although it is in APM format, nothing forces TiVo to stick to a true APM format.
Common partition tools don't work on TiVos. Even so, expanding the MFS media partition in the APM will not increase the size of it inside the Media File System itself.
I'm thinking they ditched APM entirely and just went to GPT. Why reinvent the wheel? The chipset probably even has native support for it.
 
#22 ·
Could have. Need to get a full DvrBARS backup of one of those drives. It seems that there is some program stub on a flash drive that initializes any drive that gets installed. Some think the OS is on the flash and just the MFS is on the drive, others think the program stub downloads the OS to the drive as well as initializes the MFS on the drive. Will only know once we look.
 
#23 ·
Could have. Need to get a full DvrBARS backup of one of those drives. It seems that there is some program stub on a flash drive that initializes any drive that gets installed. Some think the OS is on the flash and just the MFS is on the drive, others think the program stub downloads the OS to the drive as well as initializes the MFS on the drive. Will only know once we look.
Yeah, I posted in the thread that it would really help if the person who did that upgrade did a full DVRBARS backup of the never-booted original drive and sent it over to the DVRBARS author, it would be a great service to the community.

I got zero replies on that post.
 
#24 ·
Yeah, I posted in the thread that it would really help if the person who did that upgrade did a full DVRBARS backup of the never-booted original drive and sent it over to the DVRBARS author, it would be a great service to the community.

I got zero replies on that post.
TiVo may be shipping blank drives with all the new Roamio TiVos so no backup could be made, that would be one cost advantage TiVo has with a self formatting drive system, no preloading of the new hard drives with any software. Just purchase the OEM blank drives and put them in the Roamio.
 
#25 ·
TiVo may be shipping blank drives with all the new Roamio TiVos so no backup could be made, that would be one cost advantage TiVo has with a self formatting drive system, no preloading of the new hard drives with any software. Just purchase the OEM blank drives and put them in the Roamio.
True. But with a raw sector-by-sector backup, you can still copy even a blank drive (which will be a ton of zeroes).

If there is anything on there at all, a raw copy would copy that.

I'm not disagreeing with you. We just don't know what, if anything, is on a stock drive (for sure).
 
#26 ·
Yeah, we won't know for sure until we operate. I'd be REALLY curious if a stock Roamio goes through the same "upgrade" as the screenshots posted earlier today of what it does with a raw drive.

My best guess at this point is that the OS and a backup boot partition could easily be contained on less than 2GB. Personally, I'd put the SQLite database and the /var partition on the hard drive and only keep the OS on flash, but that's just a WAG on my part.

I will be buying a Plus or Pro in the next few days even though I don't have a cable connection to test it with. We'll figure it out but I wouldn't expect any solid answers to any of these questions for several weeks.
 
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