Hello VOGONS!

I recently bought the Hand386 device from Aliexpress, its a 386sx device using an M6117D CPU that fits in your hand (more info here: https://www.tomshardware.com/news/hand ... FO7PrIxH4o)

While it runs and boot DOS 6.22, I wanted to boot FreeDOS on it mainly for a couple open source projects I'm developing, but unfortunately, I'm not able to boot it at all.

General context:
- Using a 4GB CF card as hard disk. BIOS seems to detect it and supports LBA addressing (AFAICT, I haven't actually tried it explicitly with software), detected CHS is 7970C 16H 63S.
- DOS 6.22 on that same card shows all 4GB in fdisk
- When booting I see "FreeDOS" and it just hangs there indefinitely, HDD flash blinking periodically every 2-3 seconds
- I tried removing KERNEL.SYS and it doesn't even complain when booting before getting stuck, which makes me think that it's the bootloader that is failing, not the kernel.

I'm not too familiar with debugging these issues, but here's a list of things I've tried:

- Installing FreeDOS using a virtual machine with a physical disk pass through: This is what worked in order to install DOS 6.22. It boots fine in the VM, but gets stuck on hw
- Installing GRUB4DOS and chainloading FreeDOS. Again works on VM and not on real hw. After a couple seconds (after the stage1 bootloader timeout expires) it prints a couple messages with the drive that it's booting from (0x80), H=128 (This is LBA translation, but I also tried CHS mode) and then shows '(hd0, 0): FAT32' and then reboots immediately.

To me it seems that either the bootloaders are using some instruction or feature that the M6117D is not compatible with, or that perhaps the BIOS is botching some disk interrupts?

Looking for tips on what to check next or other things to try.

Thanks!