On 03/09/12 14:30, Ian Campbell wrote:
Hi Ian,
Apparently kvmarm@ is the place for boot-wrapper discussions so apologies for the otherwise Xen related mail ;)
The following implements support for a very basic protocol for loading multiple "modules" and providing them to the kernel. The ARM port of Xen uses this to support passing both a dom0 kernel and initrd to the hypervisor "kernel".
The Xen side of this can be found in the series at: http://lists.xen.org/archives/html/xen-devel/2012-09/msg00065.html
With that you can boot Xen on arm using the semi-hosting feature of the model (paths are host paths): $MODEL linux-system-semi.axf -C cluster.cpu0.semihosting-cmd_line=\ '--kernel xen-arm.bin \ --module zImage earlyprintk=xenboot console=ttyAMA1 root=/dev/mmcblk0 ro \ --dtb vexpress-v2p-aem-v7a-xen.dtb -- dom0_mem=256M'
Until we know what bootloaders are going to become common in the ARM servers world it hard to know who we should be working with to define a proper protocol going forward and which bootloaders to supply patches for etc. If anyone has any pointers that would be very useful.
I don't have any useful insight about bootloaders (I tend to hate them all ;-), but what we (KVM/ARM) need is something that implements the "boot in HYP mode" thing, as described here:
https://lists.cs.columbia.edu/pipermail/kvmarm/2012-August/002829.html
From a discussion with Stefano last week, it looks like this protocol
can fit Xen as well, but it would be nice to have a formal Ack before we push this into RMK's patch system.
Thanks,
M.