Yeah It can really be something fairly simple like this with a log and damp place. Though mushroom growing can need to be extremely sanitized from what i've read in guides. Because it's very easy for other fungi or molds to get in and take over your cultivation area. Avoiding that back in the 1800's mostly came down to timing/ ideal conditions for the chosen mushroom/ and luck.
From what i can tell the only mushrooms we have are white button, Cremini and Fly Agaric
I think the concept of just using a log outside ones hut and doing a simply direct process like you mention could totally work, but maybe it's a low yield? Where-as the process below is a bit more effort, but has a chance for bigger yeild.
Yeah i'm not thinking anything that complex. But still something that takes at least a little effort.
Overall I'm basically thinking like you do the whole drilling wholes in a log thing, Soak it in a barrel (maybe not full & just plain water) essentially just to slightly soften it.
Have new mushroom based item (ether called stalk or mycelium) that you would get from picking the whole mushroom rather than just cutting it.
- Crush and mix 5-10 of these with equal parts bonemeal, hay(or maybe something like woodshavings) and 1-2 parts gravel.
- dig a hole 2 blocks down. place the log in the hole. cover the log with the mixture. water. cover the hole with dirt.
After that idk, a week... maybe 2(or even a few days depending on what feels right given how the time in the game works), and then you have a new mushroom area.
I'd say maybe it only would work in shaded area's, ideally near more trees. 3-5 block radial spread of potential mushroom growth. Maybe with a percent chance based on darkness & distance from trees for each block?