[Buildroot] Newbie boot and fs mount question

[Thomas Petazzoni <thomas.petazzoni@free-electrons.com>]

Dear Mathew Benson,

On Tue, 22 Dec 2015 10:07:35 -0600, Mathew Benson wrote:
> How do I mount / from sda1 rather than RAM disk?

Pass root=/dev/sda1 on your kernel command line.

> Sorry for the simple question and let me know if there is a better forum
> for this.  I'm new to buildroot and busybox and haven't compiled a custom
> kernel in at least 15 years.  I'm using the latest version of buildroot as
> of this weekend, used the predefined i386 config, and built with kernel
> version 3.8.17.  It seems to boot just fine but it appears the file system
> is mounted from the initial RAM disk.  Any change I make to the file system
> is volatile.  What do I need to do to make it mount / from sda1 instead of
> the RAM disk?

We don't have anything like a "predefined i386 config".

However, you can see how to use a root filesystem from storage by
looking/building our Qemu x86-64 configuration:

	make qemu_x86_64_defconfig
	make

And then read board/qemu/x86_64/readme.txt for the details on how to
start this configuration under Qemu. You can see in this readme file
that we're booting the kernel with root=/dev/sda, since the first hard
drive is emulated using the contents of output/images/rootfs.ext2.

Best regards,

Thomas
-- 
Thomas Petazzoni, CTO, Free Electrons
Embedded Linux, Kernel and Android engineering
http://free-electrons.com