Re: [PATCH 0/16] arm: support for initial modules (e.g. dom0) and DTB supplied in RAM

[David Vrabel <david.vrabel@citrix.com>]

On 03/09/12 14:28, Ian Campbell wrote:
> The following series implements support for initial images and DTB in
> RAM, as opposed to in flash (dom0 kernel) or compiled into the
> hypervisor (DTB). It arranges to not clobber these with either the h/v
> text on relocation or with the heaps and frees them as appropriate.
> 
> Most of this is independent of the specific bootloader protocol which is
> used to tell Xen where these modules actually are, but I have included a
> simple PoC bootloader protocol based around device tree which is similar
> to the protocol used by Linux to find its initrd
> (where /chosen/linux,initrd-{start,end} indicate the physical address).
> 
> In the PoC the modules are listed in the chosen node starting
> with /chosen/nr-modules which contains the count and then /chosen/module
> %d-{start,end} which gives the physical address of the module
> and /chosen/module%d-args which give its command line.

Until there is an agreement on this protocol I would prepend a "xen,"
prefix to the node names (xen,nr-modules etc.).

bootargs instead of args would be more consistent perhaps. So,
module1-args becomes xen,module1-bootargs.

The proposed protocol is functional and useful using nodes for each
module seems to be more device-tree-ish. I think in the longer term,
perhaps something like the following would be better?

chosen {
    module@1 {
        compatible = "multiboot-module";
        regs = <0x12345678 0x01000>;
        bootargs = "frob";
    };
    module@2 {
        compatible = "multiboot-module";
        regs = <0x12345678 0x01000>;
    }
}

David