Example of ARM based linux board using initramfs and serial console

[Michael Nolin]

--- On Fri, 7/11/08, Thomas Charron <twaffle at gmail.com> wrote:

> From: Thomas Charron <twaffle at gmail.com>
> Subject: Re: Example of ARM based linux board using initramfs and serial console

> > > says it can be a root FS by the kernel.
> >  We're still talking Linux, right?
>  (The kernel will panic if it then cannot
> find an initial
> > program to start, but it will still mount the
> filesystem first.)
> >  You may be thinking of the "rdev" field in
> the kernel boot image
> > file.  It gives major and minor numbers for the
> default root device,
> > which are used if you don't specify a
> "root=" argument on the kernel
> > command line.
> 
>   I was talking specifically about an initramfs, which
> specifically
> uses cpio.  initramfs.c checks for a magic flag in the

I would recommend "Understanding the Linux Kernel" and "Linux Kernel Development Second Edition"

kernel/init 

        do_mounts.h         do_mounts_md.c    Kconfig  Makefile   version.o
do_mounts.c        do_mounts_initrd.c       initramfs.c     main.c   
do_mounts_devfs.c    do_mounts_rd.c          version.c

These files and kernel initialization is explained in these references. Very little if any ARM specific dependencies here.

grep -i ARM *
Binary file built-in.o matches
Binary file do_mounts_initrd.o matches
Binary file do_mounts.o matches
Binary file do_mounts_rd.o matches
Binary file initramfs.o matches
Kconfig:        default y if ARM || H8300
Kconfig:config OBSOLETE_MODPARM
main.c: printk("early_parm_test: %s\n", rest ?: "(null)");
Binary file main.o matches

My own project had a generous block of DDR memory for the creation of this ramfs. 

Michael Nolin
Embedded Solutions Unlimited, LLC