So, how to create a WhdLoad slave for my own game?
 

See title.

Inviyya is almost finished now, and I would love to create an WhdLoad slave for it for the digital version.

Any pointers on how I could accomplish this?

Have you checked the developer archive and the docs already?: http://whdload.de/docs/en/index.html

I have a researched a lot of stuff on this topic, but at the moment I cannot make neither heads nor tails of it..

I am rather confused about the whole subject and don't even know where to begin.

I think the first question is to use disk image(s) or files from your game. http://whdload.de/docs/en/howto.html
The WHDLoad experts can sure enlighten you. :)

subcontract it then.

The point of WHDLoad is to patch deficiencies in the original game. So, if your game is correctly programmed, there will be no need for a WHDLoad slave.

This is not entirely true.
You can have a properly programmed game that works on any machine but you also want to support a simple A500, using all the memory and a bare floppy loading.
So a WHDLoad slave could just make it available for HD loading and preserve OS (but requires an expanded machine).

There was a thread on this topic a few years back (see HERE). The WHDLoad docs are a good place to start, although you probably need to look at some tutorials to make more sense of them:

https://is.gd/MpwlMb (Strider WHD by Codetapper)

http://zakalwe.fi/~shd/amiga-cracking/mfminstalling.txt (Pac-Land WHD by Codetapper)

http://zakalwe.fi/~shd/amiga-crackin...stallation.txt (ATR Xmas coverdisk WHD by Codetapper)

http://zakalwe.fi/~shd/amiga-cracking/ (Two general guides on AGA fixing by Codetapper + a couple of cracking guides + more)

Thanks a lot, guys...

Will have a read into this and report back... :)

it's extremely difficult to create a startup/cleanup code that supports all CPUs, MMU configurations, VBR relocation, caches, CIAs... and is able to restore them back when quitting.

whdload is the best program ever for that. Even Tiny Bobble which has an excellent startup & cleanup code triggered a recoverable alert on my (emulated) machine upon quitting. Whdload version doesn't have this issue. Plus if your program performs illegal read/writes, whdload will catch that.

(of course whdload can't avoid blitter overwriting part of the unsaved chipmem, but that's a cornercase)

As I said (in "subcontract it"), I can help with the whdload slave. Then you can read the source and knowing your program will help you figure out what's needed to create a whdload slave.

The question is how much OS do you use in your game.
If you mainly only use memory allocation and dos.io it will be not much effort to make a whdload slave. (grep _LVO ...)
You could use defines to create a version with/without whdload.
Because the slave must be non-relocatable I would recommend to load your main program into ExpMem. You should probably use some fixed memory setup or write an own memory allocator.

I would have started with WHDLoad during development to benefit from memory protection etc. and later adapted to run it without ;)

Just send me a PM if you need assistance.