The trick with initramfs and initrd is that the kernel does not read them into memory. By the time the kernel boots, they are already in memory. This let’s you move a lot of initializing logic out of the kernel and into userspace. In some sense, this just moves the problem to the bootloader. But the bootloader already has to load the kernel, so that is no real loss.
This is also incredibly useful for stateless VMs. You do not need to futz around with virtual drives. Just put everything you need into a CPIO archive, then pass that and and your kernel into QEMU (or your emulator of choice) and it will just work.
How do you get the folder?
The trick with initramfs and initrd is that the kernel does not read them into memory. By the time the kernel boots, they are already in memory. This let’s you move a lot of initializing logic out of the kernel and into userspace. In some sense, this just moves the problem to the bootloader. But the bootloader already has to load the kernel, so that is no real loss.
This is also incredibly useful for stateless VMs. You do not need to futz around with virtual drives. Just put everything you need into a CPIO archive, then pass that and and your kernel into QEMU (or your emulator of choice) and it will just work.