New Raspbery Pi 3B+ does not boot

[buzz53]

I need to replace a dud Raspberry Pi 3B+ in my PAW classic but the new one does not boot. It continuously gives 4 long and 7 short flashes on the green LED (on the PI itself).  After much digging it seems this usually happens due to a change in the Pi 3B+ hardware about 3 years ago. The power management chip was changed and unless the boot firmware on the SD card is updated, this new device is not recognised and it thinks there is a power supply fault, giving the LED flash pattern I described. Given the apparent age of the PAW files this sounds likely to be the case.

The official fix is simply to replace 8 boot files (startup*.elf and fixup*.dat) in the boot partition with ones from a more recent version of the OS but this doesn’t seem to work with the PAW setup. What I have tried:

Created a standard Raspberry Pi OS card (Bookworm 32 bit) works fine, suggests the Pi3B+ is OK.
Created a new Pilotaware card from scratch with the latest issue, doesn’t work on 3B+, OK on 2B.
Copied the 8 updated boot files to the PAW boot sector, no change (still works on 2B, not 3B+).

I don’t know exactly how the PAW boots but I wonder if it is not using the new files that I copied over. Does it perhaps use files from the recovery partition instead and if so what files should I replace there?

Before I spend a load more time, I wondered if anyone has got PAW running on a recently purchased Pi 3B+ and obviously would appreciate any comment from PAW?

[exfirepro]

Hi Alan,

The 'official' Rosetta Pi was - at least until recently - the Pi3B, not the 3B+, but I have been running a PAW on a 3B+ for several years now with no issues, and I'm fairly sure the final batch of Rosettas were built on 3B+'s.

Have you tried a full install using the latest (20241006) Full Installation Image available from https://pilotaware.lode.co.uk/ ? It should run fine on a 3B+.

Regards
Peter

[buzz53]

Hi Peter,

Yes that was the version that I tried. Like you, I have been using a Pi3B+ for some time but it recently packed up and needs replacing. The problem is that the Pi3B+ that you can buy today (Version 1.4) is not quite the same. The power management chip has changed and needs different code. They have kept this rather quiet but it is all taken care of if you use a modern version of the OS. I suspect the PAW OS version, which seems to date from 2018, doesn’t have that. Here is a thread from the Raspi forum which exactly describes the issue:

https://forums.raspberrypi.com/viewtopic.php?p=2147085&hilit=3b+version#p2147085

In brief:

1) The Stretch operating system (used by PAW I believe) does NOT support the new Pi 3B+ version out-of-the-box.

2) Overwriting 8 or 9 files in the boot partition with the ones from a newer OS version DOES fix the problem on a standard Stretch system, and for many people this is the answer.

3) There are others, especially those using a closed image such as is the case with PAW, for whom this does NOT fix the problem. The implication is that there is something else apart from the bootloader that needs fixing. Unfortunately nobody seems able to answer this although it has arisen on multiple Raspi forum threads.

I'm  hoping the PAW people will be able to shed some light.

Alan

[exfirepro]

Hi Alan,

OK, I have read the documents you linked to.

Way above my 'pay grade' I'm afraid (I'm predominantly a volunteer and not a software engineer), but I will flag this up to Lee and see how difficult it would be to adapt the software. Don't expect an instant response however, as he has just moved house and with the phasing-out of Rosetta I'm not sure that such a change would command a sufficiently high level of commitment. I'm NOT saying that he won't do it - just that we shouldn't raise our hopes too high!

Best Regards
Peter

[A_Vinning33]

Hi Alan,

The recent changes to the power management IC on the newer Pi 3B+ models have introduced compatibility challenges with older software, including the PAW OS. Unfortunately, these changes mean that newer versions of the Pi 3B+ are not supported by the current PAW setup.

It’s worth noting that adapting our software to address this issue is not currently on our roadmap, as our reliance on the Raspberry Pi platform has significantly decreased since the launch of the PilotAware FX system.

If you’re able to return the newer Pi 3B+ to where you purchased it from, we still have a supply of compatible Pi 3B+ units available for purchase. These units have been tested and are fully compatible with the PAW setup.

Let us know if we can assist further!

All the Best,

Ashley

[buzz53]

Hi Ashley, many thanks for that. I was at a loose end today so investigated a bit further and it seems it is quite easily fixed with basic IT skills. I was on the right track yesterday, but the reason the standard fix didn’t work is that PAW uses the old NOOBS installer which I wasn't familiar with and which doesn’t directly load the operating system. This means you need to replace the old firmware files in 2 different places. In case it’s of interest to anybody else, this is what I did :

Get a copy of a recent Raspbery Pi distribution – I used Bookworm 32 bit. You will need 9 files from the distro root: bootcode.bin, start*.elf (4 files)  and fixup*.dat (4 files). Ignore the ones with "4" in the filename - these are for Pi model 4.

Take the SD card from a working PAW installation and mount it on a Windows PC (other OS's are available but don't ask me!) using an adapter. You should see 2 volumes: BOOT and RECOVERY

1) In the BOOT volume root, you will see the old versions of the above 9 files. Overwrite them with the new ones.

The additional steps, that I was missing yesterday are:

2) In the RECOVERY volume root, overwrite bootcode.bin with the new version.
3) In the RECOVERY volume root, delete recovery.elf, copy in the new start.elf and rename it recovery.elf.

That’s it! If you are starting with a brand new PAW card that has not yet been run, and you don’t have an old version Pi in which you can do so in order to set everything up, then it’s a bit more fiddly but you get the idea.

I think Lee could probably update the official image quite easily to reflect this.

Kind regards, Alan

[Admin]

Hi Alan
So to confirm, you are confident this resolves the issue on the newer hardware ?
If so I will try it out, just need to make sure it does not affect the older hardware platforms
Thx
Lee

[buzz53]

It's only been ground tested in conjunction with a SoftRF device but seems fine. It's only the boot process that's different after all.

I have also checked on a Pi 2B and that is OK too as far as I can tell - the licence doesn't work obviously.

But yes - please check it out!

Alan