Run Linux completely from ramdisk (initramfs)
Hello to everybody, this is my first posting here!
I have a question concerning the boot-process in linux. I want to achieve that my linux is booting completely from initramfs. My system is completely diskless. So what I have already done:
I'am running CentOS 5.9 (Kernel 2.6.18-348) on a machine that has not any disks inside. So I want to have a diskless boot-process. In the planned production environment this machine will boot from network (pxe). Booting from network works like a charme and the initramfs is loaded into memory correctly.
Normally the initramfs is used for setting up an inital filesystem to load some drivers that are not compiled into the kernel. After the actual filesystem is mounted successfully the root-mount-point is switched to that new filesystem and the system can start from there. As I figured out the system calls '/sbin/init' from the new filesystem (which is now the root-filesystem).
I want to skip this last step, so my whole system is completely included in the initramfs at root-mount-point. The filesystem at this stage is "ramfs". My whole embedded system is already configured and packed into an initramfs-image (cpio-archive that is gzipped). That is not a problem at all.
First of all: is it possible to run the entire system from a ramdisk?
Thanks in advance and nice greets from Germany!
PS: Sorry for my bad english but I am not a native speaker.