Im learning about Virtualization framework from Apple, and Im currently trying to create an Arch Linux environment to run on top of it. Im still a bit confused about few concepts regarding how this works, so I gathered them into 3 sections.
Kernel and Initial Ram Disk (initrd) usage.
From what I learned to start Virtual Machine, I need to have extracted linuz and initrdfiles, and use them to create a bootloader. This is kind of different approach from other VMsolutions, but I think I get why it is. But to make sure few questions: Since Im loading the kernel and initramdisk at this step, I can extract exact files from my linux distribution disk image, and remove them from linux /boot folder right? And going forward since this is a bootloader, I don’t really need to install Grub to run it, right?
Kernel and inited capabilities and format.
Until now I was only able to run a single kernel and initrd - some Ubuntu cloud 20.04images downloaded from the internet. I tried also other versions of Ubuntu, and my own Arch build, but it usually ends with either some error or sometimes virtualMachine.start()returns success but after that nothing is happening. I think I need either to compile some required features into the kernel (but have no idea which) or have these files with some specific format. I noticed that when using file command on initrd I get different information about these files. For example, the one from Ubuntu that works for me is: LZ4 compressed data (v0.1-v0.9). The other one I tried, but didn’t work was Zstandard compressed data (v0.8+), Dictionary ID: None. Does that play a role here? If so how to prepare initrd in correct format?
Virtual disk format.
After booting into the environment I would like to perform Arch Linux installation on separate virtual disk, and later switch to use this disk as the main one. How should I prepare .img empty file to use? From Disk utility Im only able to prepare .dmg format. Can I use some other formats as well? And later how should I partition this disk? I was planning to create GTP partition table with just a single Linux ext4 partition. On other Virtual Machine I was also creating a 1MB partition for Grub, but I think this can be skipped here. Is that correct?
Do I need initrd?
I think that I will need to compile my own kernel to achieve nicely working environment. And this might be the good solution for me. If that's the case do I really need initrd at all? Would it be possible to create fully prepared kernel that boots without it? If so what features do I need to use in kernel config?