On 01/26/2015 01:37 PM, Markus Armbruster wrote:
Dinar Valeev <address@hidden> writes:
On 01/26/2015 10:11 AM, Markus Armbruster wrote:
address@hidden writes:
From: Dinar Valeev <address@hidden>
In order to use -boot once=X option we need to have default list
where restore to on reset.
Really? What happens without this patch?
qemu segfaults on reset.
0 > reset-all Segmentation fault
Next time, include a backtrace, please.
Ok, sorry for that.
Here's what I think happens.
Boot order comes from --boot parameter once, order, or else the machine
type's .default_boot_order. The latter is null for you.
It gets passed via ppc_spapr_init() to spapr_create_fdt_skel(), which
sets qemu,boot-device in the FDT to it, but only when it isn't null.
If it comes from parameter once, we additionally register a reset
handler to switch it to parameter order or else .default_boot_order on
reset. If you specify once, but not order, this is null for you.
On reset, reset handler restore_boot_order() runs. Unlike
spapr_create_fdt_skel(), it doesn't check for null, and crashes in
validate_bootdevices().
Correct?
Yes
qemu_register_boot_set is implemented in PATCH 2/2. on reset
boot_device is restored to NULL
For me, a null .default_boot_order means "machine type does not support
boot order" (this is how commit c165473 treats it). Arguably, --boot
order and once should be rejected then.
AFICS SLOF handles qemu,boot-device as boot device, if nothing passed
then it goes disk, cdrom, network. Which is the same as "cdn" list.