System Flush Finally Fixes Developing Problems While Trialling CF

[bottletop]

I adapted my idea from end of post #74.

System/Power Management/Automatic Power Down/Off
Set fan speed 65 (as it'll be hot today)

Added some manual schedules as reminder (this should switch channels)
0800-0900 BBC1 (LCN 1)
0900-1000 London Live (LCN 8)
1000-1100 BBC News (LCN 231)
1100-1200 Sky News (LCN 233)
1200-1300 Talking Pictures TV (LCN 82)

I'll check later to see if the HDR crashes.

Edit1: Test completed without errors. Temperature reached 38c. No crash. No reboot. I doubt op's issue(s) are to do with Custom Firmware, standard Humax firmware or transmission.

 

[Newcoppiceman]

An update now that I've performed a system flush on the faulty PVR in a moment, but first some questions arising:

1. Every time the faulty PVR started yesterday (apart from once), after the display had shown the CF version it showed first ENTERING, then RMA, then MODE. This message triplet doesn't appear in the instructions to remove the CF so what does it signify? In other words, what is this "RMA mode" the PVR has entered? [The one occasion when the PVR started and didn't show ENTERING, RMA, MODE it showed == RMA == which message (or at least "RMA") does feature in the removal instructions. These say this signifies all the CF components have been removed from the HDD.]
2. It seems I've removed the CF components from the HDD (and this morning done a system flush) but I've not yet done the next step in the removal instructions, namely install the official (Humax) firmware. Accordingly, the CF remains in flash and the PVR remains functional. So, is this a stable state?
3. What are the consequences of not having those CF components on the HDD?
4. Picking-up on MartinLiddle's comment at #76, does the Humax firmware reside entirely in flash (ie no HDD components)?

The fault reappeared yesterday afternoon so early this morning I did a system flush. The display said END once this had been done, then WIZARD as I was taken through the installation wizard's five stages (Preferred Language, Display, Automatic Search, Power Saving, Result). On completion the fault had disappeared; it will be interesting to see if it reappears later.

 

[MartinLiddle]

Picking-up on MartinLiddle's comment at #76, does the Humax firmware reside entirely in flash (ie no HDD components)?

As far as I know the firmware resides entirely in flash. I think you will find that you can install the standard firmware with the hard drive disconnected; I don't recollect actually doing it on an HDR-FOX T2 but I have certainly done it multiple times on earlier Humax models.

 

[Black Hole]

what is this "RMA mode" the PVR has entered?

The /mod folder has been removed from the HDD, and a flag is set in flash preventing re-installation of /mod. Look up RMA in the Glossary for background.

It seems I've removed the CF components from the HDD

See above. Did I not say most of this in post 64?

is this a stable state?

Yes. There is CF in flash, but no support on HDD. CF does not interfere with normal PVR functionality. These questions suggest you never read anything about how it all works.

What are the consequences of not having those CF components on the HDD?

Nothing happens. What's in flash are just hooks to enable stuff on HDD to run alongside the normal PVR functionality (multitasking operating system).

Picking-up on MartinLiddle's comment at #76, does the Humax firmware reside entirely in flash (ie no HDD components)?

Obviously. Take out the HDD and it still works. Derr! (You could test for your rebooting problem with the disk removed, as another data point.)

The point of RMA is to clean up the unit in the event of a warranty return, so Humax couldn't know the user had been fiddling with it. None of that is now relevant, but RMA is also a convenient way to rip it up and start again. What little remains in flash after RMA is wiped by re-flashing with standard (not custom) firmware. The CF modifications to the flash image provide basic stuff like Telnet, a web page for installation of the WebIF to HDD, and a hook so that the OS goes looking for stuff to run on HDD at boot time. That is all.

The OS is open source, therefore Humax were obliged to publish details and once we (not me!) had cracked the firmware update process we could add some user access. The actual code which Humax runs using the OS is an undocumented binary executable, which is why we don't have access to the PVR functionality and don't interfere with it. That is why we are so sceptical that the CF has anything to do with reboots when you happen to tune to TPTV. Everything to do with that is of Humax origin, and will be present whether you are running CF or not.

 

[Black Hole]

And please don't call the stuff on the disk "FW" as that just confuses the issue. Firmware is the stuff in the "read-only" flash. Stuff on the disk is "packages" or "software".

That is a bit harsh. We have customised firmware in flash, and that is supported by software components on the HDD. It is not unreasonable to refer to the overall as "CF" for short, but it does mean we end up having to educate people where the different bits reside (if they insist on not reading up for themselves). However, I agree FW (FirmWare) can only refer to the flash image. See Glossary entry Firmware v. Software.

 

[Newcoppiceman]

The /mod folder has been removed from the HDD, and a flag is set in flash preventing re-installation of /mod. Look up RMA in the Glossary for background.

Thanks. My reference for this work has been the Remove Modified Firmware Wiki; the glossary entry explains the origin of the term RMA (as I was manager, electronic maintenance at C4 for 7 years I was aware of this).

Did I not say most of this in post 64?

The further and better particulars are welcome. In #64 you referred to accessing the web address, which I've not been doing; I've just been monitoring the PVR's display. I've not used the web interface since Saturday when I primed the RMA process.

These questions suggest you never read anything about how it all works.

I haven't come across a proper under-the-bonnet explanation of the CF. Assuming the issues which have surfaced since installing CF can be sorted - and I don't revert to the Humax firmware - I would be interested in learning about how it all works, naturally.

Nothing happens.

You mean beyond the functionality provided by the Humax firmware the CF is built on, I take it.

You could test for your rebooting problem with the disk removed, as another data point.

I did try this some weeks ago (#50) - the fault remained.

That is why we are so sceptical that the CF has anything to do with reboots when you happen to tune to TPTV. Everything to do with that is of Humax origin, and will be present whether you are running CF or not.

As prpr says (#79) maybe there was a file corruption problem which the system flush has fixed: I turned the PVR on an hour or so ago and the display went straight from the CF version to the selected service. No sign of the fault so far.

 

[Black Hole]

maybe there was a file corruption problem which the system flush has fixed

System flush is a tool for clearing structures that the standard firmware uses. It's applied as a flash update because of that. CF not implicated, and it's difficult to suggest a scenario which explains how system flush would cure crash/reboots on specific services.

 

[Black Hole]

I haven't come across a proper under-the-bonnet explanation of the CF.

Well, no. Documentation takes at least as much work as actually developing the code, and only those who develop the code have sufficient knowledge to write documentation. But there is enough explanation to have answered many of your questions.

The Custom Firmware does not interfere with the normal day-to-day operation of the HD/HDR-FOX, and you will see no difference to the user interface on the TV screen

The HDR-FOX (and HD-FOX) hardware (ie the electronics) is a "black box" - ie a mystery to us, hidden inside some very large scale integrated circuits with documentation Humax keep to themselves. We can guess the general architecture of what's inside, but not the detail. To compound the problem, the Humax software (which we can inspect) that operates the mystery hardware is also an undocumented "blob" of binary code and (essentially) also a mystery.

The consequence is that we have no access to the video and audio streams sent out on the HDMI, SCART, and RCA socket, or the graphics overlays, and cannot affect them except in very limited indirect ways (one rare example being substituting our own set of digit graphics for the screensaver clock)...

What has been achieved with Custom Firmware is to provide a way in to the HDR-FOX's open source operating system so that our own applications can be run alongside the Humax application. These applications have access to everything the operating system has access to - ie networking, file system, and process status. With a very few rare exceptions, everything the CF does is by manipulating the files and file system, with command and control via a web browser or command line interface over the network.

The only way the CF can have any bearing on reception issues is if it causes the processor to become overloaded. In general all CF process are given a low priority to ensure this doesn't happen, but a corrupted / failing HDD can result in system retries which are not limited in priority. That's why we are continually advising people to check SMART and run fixdisk.

Crashing on specific services is not a CF thing, and any correlation you think you've found between CF/SF and crashing/not crashing is an illusion. If crashes were occurring because of the CF, they would not be tied to any specific service without implicating the HDD (eg: HiDef services impose a greater data rate on the TSR buffer).

Fundamentally: if there is a problem with the CF, it will be a problem for everyone running that version of CF. If it's a problem which only afflicts one unit, then there is some kind of problem with that unit.

 

[Newcoppiceman]

Still fault-free at 1700. Will check once more before substituting the spare PVR for evening viewing.

 

[prpr]

What little remains in flash after RMA is wiped by re-flashing with standard (not custom) firmware.

No, that only overwrites the "read-only" flash. The "read/write" flash filesystems (2 of them) are re-made and thus cleared by the System Flush image.
The order in the post referenced in post #69 states the order of doing stuff to make sure things are set back to completely clean, if anyone actually bothered to follow it.

 

[prpr]

That is a bit harsh.

I disagree. In a thread such as this, the detail is important, and therefore so is the terminology and being specific about things.
Using words where nobody is quite sure what's meant doesn't help anyone.

 

[Newcoppiceman]

No, that only overwrites the "read-only" flash. The "read/write" flash filesystems (2 of them) are re-made and thus cleared by the System Flush image.
The order in the post referenced in post #69 states the order of doing stuff to make sure things are set back to completely clean, if anyone actually bothered to follow it.

So the order should be:

1. RMA
2. Reboot
3. Standard Firmware
4. System Flush

(I omitted step 3 because I wanted to see if the system flush fixed the fault without making any other changes at the same time.)

 

[Newcoppiceman]

Well... It looks like the system flush and the re-creation of the R/W flash filesystems has done the trick. I won't make any further changes (like installing the Humax FW) until the PVR has been fault-free for at least a week and we can think about returning it to full service.

Big thanks to everyone who has contributed (I know it's been frustrating at times) but I guess we've all learnt something.

 

[prpr]

It looks like the system flush and the re-creation of the R/W flash filesystems has done the trick.

Interesting. I don't think we've ever had this confirmed before.

 

[Black Hole]

It looks like the system flush and the re-creation of the R/W flash filesystems has done the trick

The next question being why, how?

 

[Newcoppiceman]

The CF was installed over the weekend of 12/13 Nov 2023 and problems first logged in my 15 Nov post, including the "melt-down" we had that evening (https://hummy.tv/forum/threads/faul...tion-problems-on-some-muxes.11086/post-170227). This was followed-up a couple of days later in a new thread (https://hummy.tv/forum/threads/two-...ng-cf-1-03-12-on-hdr-fox-t2.11098/post-170288).

It's easy to conclude from this that installation of the CF created some issue with the R/W flash filesystems - how this has manifested has changed significantly over time - but it may be totally unconnected of course.

Wouldn't it be something to fully understand what happened to the filesystems to cause these problems, most recently the, by now, well-characterised freeze-and-reboot cycling - but on some services only? Realistically, though...

Assuming this is a solid fix it demonstrates the potential of a system flush to cure all sorts of nasties, so it might be worth re-titling/locating this thread for the benefit of others.

 

[Black Hole]

Assuming this is a solid fix it demonstrates the potential of a system flush to cure all sorts of nasties, so it might be worth re-titling/locating this thread for the benefit of others.

We already suggest a system flush as a panacea for otherwise unexplained ills, where it seems possible that the internal data structures are involved. This case just widens the range of ills for which it is a potential cure.

I suggest you identify where in this thread you started talking about reboot cycles, and ask the mods to split the thread with an appropriate title (use the Report button).

Wouldn't it be something to fully understand what happened to the filesystems to cause these problems, most recently the, by now, well-characterised freeze-and-reboot cycling - but on some services only? Realistically, though...

As an engineer, I don't like "magic". Without an explanation, this does seem to be bordering on magic.

It's easy to conclude from this that installation of the CF created some issue with the R/W flash filesystems - how this has manifested has changed significantly over time - but it may be totally unconnected of course.

Aside from my single instance of continual reboots on TPTV, yours is the only report of this kind of thing I know of so it can't be anything intrinsic to CF, and it is hard to see how even a defect during CF installation could affect the settop data structures.

On the other hand, we are aware that the data structures can get "out of sync" during normal operation – which is where system flush comes in.

 

[Newcoppiceman]

Main PVR has been working faultlessly since applying the system flush a week ago, so today I reinstalled Humax 1.03.12. Thread also retitled (from After 5 Months with CF, Removing for a While).

 

[Newcoppiceman]

It's exactly a year since I first installed CF when I was trying to resolve a problem which turned out to be due to a faulty aerial amp PSU. It seems I was very unlucky that this caused all manner of problems. Pleased to report that the PVR has been working faultlessly for 5 months now after performing a system flush. I might try the CF again one day...