Occasionally the users try to mix the bootindex properties with the
"-boot order" parameter - and this likely does not give the expected
results. So let's add a proper statement that these two concepts
should not be used together.
Signed-off-by: Thomas Huth <thuth@redhat.com>
---
docs/bootindex.txt | 9 +++++++++
qemu-options.hx | 5 ++++-
2 files changed, 13 insertions(+), 1 deletion(-)
diff --git a/docs/bootindex.txt b/docs/bootindex.txt
index f84fac7..9e0ac07 100644
--- a/docs/bootindex.txt
+++ b/docs/bootindex.txt
@@ -41,3 +41,12 @@ has three bootable devices target1, target3, target5 connected to it,
the option ROM will have a boot method for each of them, but it is not
possible to map from boot method back to a specific target. This is a
shortcoming of the PC BIOS boot specification.
+
+== Mixing bootindex and boot order parameters ==
+
+Note that it does not make sense to use the bootindex property together
+with the "-boot order=..." (or "-boot once=...") parameter. The guest
+firmware implementations normally either support the one or the other,
+but not both parameters at the same time. Mixing them will result in
+undefined behavior, and thus the guest firmware will likely not boot
+from the expected devices.
diff --git a/qemu-options.hx b/qemu-options.hx
index bf458f8..aa11420 100644
--- a/qemu-options.hx
+++ b/qemu-options.hx
@@ -234,7 +234,10 @@ drive letters depend on the target architecture. The x86 PC uses: a, b
(floppy 1 and 2), c (first hard disk), d (first CD-ROM), n-p (Etherboot
from network adapter 1-4), hard disk boot is the default. To apply a
particular boot order only on the first startup, specify it via
-@option{once}.
+@option{once}. Note that the @option{order} or @option{once} parameter
+should not be used together with the @option{bootindex} property of
+devices, since the firmware implementations normally do not support both
+at the same time.
Interactive boot menus/prompts can be enabled via @option{menu=on} as far
as firmware/BIOS supports them. The default is non-interactive boot.
--
1.8.3.1
On 02/28/2017 11:40 AM, Thomas Huth wrote: > Occasionally the users try to mix the bootindex properties with the > "-boot order" parameter - and this likely does not give the expected > results. So let's add a proper statement that these two concepts > should not be used together. > > Signed-off-by: Thomas Huth <thuth@redhat.com> > --- > docs/bootindex.txt | 9 +++++++++ > qemu-options.hx | 5 ++++- > 2 files changed, 13 insertions(+), 1 deletion(-) > Reviewed-by: Eric Blake <eblake@redhat.com> -- Eric Blake eblake redhat com +1-919-301-3266 Libvirt virtualization library http://libvirt.org
On 02/28/17 18:40, Thomas Huth wrote: > Occasionally the users try to mix the bootindex properties with the > "-boot order" parameter - and this likely does not give the expected > results. So let's add a proper statement that these two concepts > should not be used together. > > Signed-off-by: Thomas Huth <thuth@redhat.com> > --- > docs/bootindex.txt | 9 +++++++++ Wow, a document from 2011! commit 466b58648a7b2ba7edb280b585e0b0c26e3be31e Author: Gleb Natapov <gleb@redhat.com> Date: Sun Jan 30 12:29:19 2011 +0200 Add boot index documentation. So cool. I didn't know this existed. > qemu-options.hx | 5 ++++- > 2 files changed, 13 insertions(+), 1 deletion(-) > > diff --git a/docs/bootindex.txt b/docs/bootindex.txt > index f84fac7..9e0ac07 100644 > --- a/docs/bootindex.txt > +++ b/docs/bootindex.txt > @@ -41,3 +41,12 @@ has three bootable devices target1, target3, target5 connected to it, > the option ROM will have a boot method for each of them, but it is not > possible to map from boot method back to a specific target. This is a > shortcoming of the PC BIOS boot specification. > + > +== Mixing bootindex and boot order parameters == > + > +Note that it does not make sense to use the bootindex property together > +with the "-boot order=..." (or "-boot once=...") parameter. The guest > +firmware implementations normally either support the one or the other, > +but not both parameters at the same time. Mixing them will result in > +undefined behavior, and thus the guest firmware will likely not boot > +from the expected devices. > diff --git a/qemu-options.hx b/qemu-options.hx > index bf458f8..aa11420 100644 > --- a/qemu-options.hx > +++ b/qemu-options.hx > @@ -234,7 +234,10 @@ drive letters depend on the target architecture. The x86 PC uses: a, b > (floppy 1 and 2), c (first hard disk), d (first CD-ROM), n-p (Etherboot > from network adapter 1-4), hard disk boot is the default. To apply a > particular boot order only on the first startup, specify it via > -@option{once}. > +@option{once}. Note that the @option{order} or @option{once} parameter > +should not be used together with the @option{bootindex} property of > +devices, since the firmware implementations normally do not support both > +at the same time. > > Interactive boot menus/prompts can be enabled via @option{menu=on} as far > as firmware/BIOS supports them. The default is non-interactive boot. > Awesome. Thank you for this. Reviewed-by: Laszlo Ersek <lersek@redhat.com>
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