From c0d9f7d0bcedeaa65d5c984fbe0d351e1402eab5 Mon Sep 17 00:00:00 2001 From: Thomas Huth Date: Tue, 28 Feb 2017 18:40:01 +0100 Subject: [PATCH] docs: Add a note about mixing bootindex with "-boot order" 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 Message-Id: <1488303601-23741-1-git-send-email-thuth@redhat.com> Reviewed-by: Eric Blake Reviewed-by: Laszlo Ersek Signed-off-by: Paolo Bonzini --- 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 f84fac7200..b9a8ba122f 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 8dd8ee34a6..99af8edf5f 100644 --- a/qemu-options.hx +++ b/qemu-options.hx @@ -252,7 +252,10 @@ 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.