Re: [PATCH v2 6/6] RISC-V: Implement keepinitrd kernel parameter

[Christoph Hellwig]

On Tue, Feb 12, 2019 at 03:53:21PM +0530, Anup Patel wrote:
> If it is initramfs (i.e. CPIO image) then contents of CPIO archive
> are extracted to create a ramfs instance.
> 
> If it is initrd (i.e. some filesystem image) then RAM block device
> is created in-place at initrd location. (Please correct me if I am
> wrong about initrd here).

No.  If it is an initrd image we still copy it into the rootfs first,
and then load it into a ram disk.  Take a look at
init/initramfs.c:populate_rootfs() and
init/do_mounts_initrd.c:initrd_load().

> So in case of initrd we might not want to free-up the RAM but
> we can certainly free-up in case of initramfs.

No, in either case we do not need the original initramfs/initrd
memory.  I suspect arm has this as a workaround for some weird
legacy boot issue, but I can't see any reason why we would not want
to free the memory on riscv.