Replicant

I noticed that the author of the first link and repository (second link) actually did an entire new QEMU. I don't know the reason for that, but I wonder if that was really needed.

In order to not ask meaningless question, I think that it's best to include the changes in QEMU (upstream), rather than fork. Was there an attempt to convince the author of the custom QEMU (second link) to contribute upstream?

I think that you can optionally specify hardware in QEMU. This would be beneficial for bootloader hacking work especially. You do seem to be correct that the author of that i9100 QEMU code didn't upstream their work. I'm not seeing their commits here in the mainline repo here

I don't think that any of us have asked the code author to upstream their work based on the fact that I rarely hear any chatter within the project about working to get Replciant working on QEMU. We have been sharing that link around for a while though, so maybe someone reached out and asked him.

That being said, on the documentation side of things, it likely would be easier to start by providing directions on how to run Replicant in QEMU without specifying any hardware, like the i9100, for it to be running on, if that's possible.

Here's a blog post from a few months ago written by a colleague of Fred, who wrote the Exynos 4210 blog post linked to above, about reverse-engineering the Samsung Exynos 9820 bootloader to get it running in QEMU: https://allsoftwaresucks.blogspot.com/2019/05/reverse-engineering-samsung-exynos-9820.html