Re: [QUERY] Building and testing Aarch64

Ramkumar Ramachandra
2013-09-28T07:57:50Z

Catalin Marinas wrote:
> git://git.kernel.org/pub/scm/linux/kernel/git/cmarinas/boot-wrapper-aarch64.git

Thanks, I made some progress. Now I'm stuck trying to specify the
rootfs. I boot with the following arguments (full fork of your
repository here [1]):

console=ttyAMA0 mem=2048M devtmpfs.mount=1 earlyprintk rw
init=/bin/sh root=/dev/vda

I copied it from the command-line parameters that
linux-system-foundation.axf uses [2]. And then boot with the raring
image specified as the --block-device in Foundation_v8 like:

$ ./Foundation_v8 --image linux-system.axf --block-device raring-arm64-rootfs

I built my linux-system.axf from my kernel tree using your Makefile.
Unfortunately, instead of the sh prompt, I get:

VFS: Cannot open root device "vda" or unknown-block(0,0): error -6
Please append a correct "root=" boot option; here are the available
partitions:
Kernel panic - not syncing: VFS: Unable to mount root fs on unknown-block(0,0)

I'm not exactly sure what went wrong: I made sure to compile my kernel
with virtio support. My confusion can be summarized as: when I specify
a file as a --block-device to the Foundation_v8 emulator, under which
device node is it available to the kernel? How do I specify a proper
root device? I tried reading through foundation-v8.dts, but couldn't
understand much.

Also, I didn't understand the part of your Makefile that deals with
the filesystem: what is filesystem.cpio.gz, and where is it going to
be used?

Thanks.

[1]: https://github.com/artagnon/boot-wrapper-aarch64
[2]: http://people.debian.org/~wookey/bootstrap/rootfs/