Is there something similar to NanoBSD in Linux

Question

NanoBSD is a script that makes light, small and in-memory FreeBSD copy. It is useful in embedded systems. Is there something similar to NanoBSD in Linux? Specially a feature like Everything is read-only at run-time as it mentioned here .

Answer 1

A lot of toolchain / system build systems build Linux root filesystems which are designed to run completely out of a ramdisc (rootfs / tmpfs). This means that everything is read/write at runtime, but it does not persist across reboots (a persistent FS can of course, be mounted as a non-root FS).

The most well known of these is Busybox (with or without uclibc), which ships with various scripts to build very small-footprint Linux-based embedded systems (root FS is typically a few Mb only; just add a kernel). Busybox/Linux is not the same as GNU/Linux, but it is fairly similar - most things are simpler or have fewer options; some features are entirely absent or can be disabled at compile-time.

Linux is NOT an Operating system like FreeBSD, rather it is a kernel. You can choose to layer either GNU C library and tools (which I think all major general-purpose distributions do) or something else - which is mostly used for smaller systems, including uclibc, Android etc.

Answer 2

There are literally hundreds of toolchains, build environments and embedded distros of Linux, some only a couple of megabytes in size. Many also support some or many of the different processors Linux runs on (i386 and friends, ARM, Power, ...).

To get you started a couple of projects I find interesting: OpenWrt and OpenEmbedded, and lpclinux, Linux for NXP LPC3xxx ARM processors but there are really hundreds of them.

Some other resources

A very good source that (also) touches a number of issues specific to embedded systems is Linux from scratch. And this pdf gives some insight in the different available filesystems for an embedded Linux system.

Answer 3

i would take a look at TinyCore-Linux. which isn't really ro but nearly the same Concept and i think there is also a was to get the OS/Binary Part ro were the config part is writeable.