Re: [Qemu-devel] nvram and boot order

[Peter Maydell]

On 16 October 2012 20:55, Anthony Liguori <address@hidden> wrote:
>
> We discussed nvram and it's interaction with boot order in today's KVM
> call.  Here's the outcome.  This list is completely incremental so it's
> fine to start with 1-4, for instance, as long as we eventually get to 6.
>
> Today, on x86, we implement up to (5) but we don't persist NVRAM.
>
> 1) We should modify QEMUMachine to specify that a machine does not want
>    a default boot order.  Ideally, this would be done by adding a new
>    default_boot_order that is set to "cad" explicitly in all machines
>    allowing a machine to remove that entry.  At any rate, this allows a
>    machine to receive a NULL boot order when -boot isn't used and take an
>    appropriate action accordingly.
>
> 2) In the absence of a persistent NVRAM, a ephemeral NVRAM should be
>    generated with a reasonable default boot order.
>
> 3) In the absence of -boot or ,bootindex=, the system should boot from
>    order specified in NVRAM.
>
> 4) If -boot is specified, the parameter should alter the contents of
>    NVRAM to change the boot order to what is specified by -boot.
>
> 5) If ,bootorder is specified, it should take predence over -boot.
>
> 6) ,bootorder= should also alter the contents of NVRAM to determine the
>    boot order.

What's the rationale for 6? It seems a bit odd for a command line
option to randomly mangle the NVRAM...

-- PMM