Various issues with the ExFat filesystem

[Mangerrione]

To use HDD-images larger than 4 GB, the ExFat filesystem is required. Which allocation unit size is recommended?
I found out 512kb works.

Experimenting with the ExFat filesystem i found various issues...

The NanoMig could not write it's config file onto the SD-Card.

Using a 14 GB HDF containing 3 partitions the 3rd partition did not show up in Amiga OS. The 3rd partition starts beyond the 4GB limit. But everything works fine when run in WinUAE, from the same SD-Card.

Random files on the 2nd partition don't show up on the NanoMig in Amiga OS. Maybe the first partition (300MB) works well, otherwise the system would not boot up. But everything's fine in WinUAE.

[harbaum]

I just added support for a "large" image command, which the FPGA Companion now uses every time an image >4GB is being loaded. Also, the NanoMig core supports that command and uses it for HDD images.

Regular HDD still works, but those "large" images are untested, yet. No binary releases of the NanoMig core nor the Companion including this, yet.

[Mangerrione]

Have built and flashed the latest NanoMig and FPGA-Companion. The issues with ExFat/Large Disks seem to be unsolved. Amiga OS can not read the 3rd partition and random files on the 2nd partition don't show up. So maybe there is still something wrong in the filesystem handling?

[harbaum]

Did you retry? The necessary changes of NanoMig required for that weren't IMHO part of the released version when you tested last.

When testing stuff and reporting issues please write which exact release you tested. Or did you build it yourelf from the repository at that time? That should have included the changes.

[Mangerrione]

I tested it about a month ago. Yes, have buildt Nanomig and FPGA-Companion freshly. Will test again soon and report in detail!

[Mangerrione]

Have built the NanoMig freshly with the latest EDA.
FPGA-Companion from yesterday.
TN20K with on board MCU.
SD card formatted with ExFat block size 512kb.
copied AGS.hdf onto it (14GB)

AGS has 3 partitions
dh0: system 300 MB
dh1: whdload 7 GB
dh2: work 5GB

the system boots up
the first partition seems to be fully working
the second partition has missing files
the third partition doesn't show up in Amiga OS

these are the same results i got about a month ago
i assume that bits beyond the 4GB barrier are not accessible?

[harbaum]

I fixed and tested it for the Atari ST and just copied the same code over to the NanoMig.

What does the debug output of the FPGA Companion say? Does it report a big file?

[harbaum]

Please publish the image file somewhere.

[Mangerrione]

Sure! Please take the AGS-Image from my Google-Drive: https://drive.google.com/drive/folders/1V6dxx0rj-lLO7XMI7whJWDDMtk67FwY7

Right now the boot process stops because the Work: partition
can not be found. Just enter "loadwb" and then "endcli" to
run the Workbench. Start AGS from the workbench menu...

[Mangerrione]

Got this little device, but haven't used it...
Can i read debug information from the on board BL616 with it?

[harbaum]

Ah ... you are using a bl616 based setup? I never tested that with the large files.

The bl616 does debug output at 2mbit/s and while many USB uarts are supposed to support that it often doesn't work. I this cannot tell if your adapter will work.

[harbaum]

Sure! Please take the AGS-Image from my Google-Drive: https://drive.google.com/drive/folders/1V6dxx0rj-lLO7XMI7whJWDDMtk67FwY7

How sure are you that this image is clean/undamaged? I am running it in simulation, and it seems to me that on the first run the Amiga tries to fix the file system and then reboot. So far, the simulation wouldn't even reach the point you are describing.

[Mangerrione]

Have downloaded and doublechecked the image. It runs fine in WinUAE, everything seems to be good. It runs on the TN20K with the flaws i have reported. All partitions are PFS3 (Professional File System) formatted. A PFS partition never becomes invalid and therefore does not need to be checked by the OS. Errors are handeled on the fly. AGS has a huge startup-sequence. It may take a long time to boot it up, especially in simulation.

after some time the boot process gets stuck because the Work: partition can not be found... cancel

with loadwb and endcli i can go to the desktop

on the desktop the Work: partition does not show up but DH2:NDOS

[Mangerrione]

Have tested also Amiga Vision. I has only 9 GB and two partitions. Both partitions show up but random files on the second partition don't exist where they should be. I assume that files after the 4GB barrier are not acessible by the OS...

https://amiga.vision/

https://archive.org/details/amigavision-2024

[harbaum]

I've come that far once on the TN20k. But the simulation stops earlier. But debugging the simulation is more reliable. I see it booting quite far. Then it reads some tables and writes them back and then stops working at all ...

Does winuae write to the disk early during boot? Can winuae be set to read only? Will the image then still boot?