newbie: conditional live RAM-RO?

[ivo welch <ivo.welch@anderson.ucla.edu>]

I am trying to learn the boot process of linux.  I assume that, as of
2014, I am now living in a EFI-GPT world.  every x86 computer worth
more than $100 should have this.

my goal is to remove the true physical boot medium asap before the
network comes up.  this way, a hacker cannot root-kit me.  the memory
cost is trivial.  my linux system is only about 2GB, which should
compress down to 1GB ($10).

my plan:  in the stage1 init (sda1 = /boot), unless I see a request
for "notoram" on the linux boot prompt, I will copy my normal physical
root partition (sda2) into a squashfs, and unmount sda2.  instead of
exec-ing for stage2 into /dev/sda2, I then simply exec into its ro ram
copy.

is this transition to stage 2 also where I can drop the physical
medium?  the relevant kernel and initrd have already been read from
/boot, so presumably the sda1 /boot partition has been copied and can
be unmounted the instant before stage2, too.

I think I can figure this out, but if this already exists or if there
are specific issues I should read up on, then pointers would be
useful.  docs are a little sparse...

/iaw