Introduction

  advantages of initramfs

    - fundamental sequencing problem: mount "/" before running init.
      - Device enumeration complicated.  (USB, anyone?  SCSI longstanding)
      - NFS mounts require dhcp and login.
      - encrypt, compress, 
      - modular filesystem driver, build into kernel.  Magic format.  Special.
        - root ext3.  Initrd ext2 _not_ ext3, journal on ramdisk!  Build in
          ext2 driver then can't get rid of it.
      - Binary only firmware for some devices (network cards).
        - Too cheap to spring for ram or flash.
          - Require a cross-compiler for mips to build your kernel?
      - initramfs has no chicken and egg problems ala nfs mounts
    - very simple implementation.  (Small, cross-platform.)
    - One file.  Bootloader simple to set up.
    - actually init
      - no assumptions about what you're going to do.  Stay running.
        - root mount not "magic".  Built-in root, ignorable.
    - moves more control to userspace
      - laptops, embedded systems, clusters, mainframes