On 8/10/20 12:18 PM, Cornelia Huck wrote: > On Thu, 6 Aug 2020 17:05:07 +0200 > Thomas Huth <th...@redhat.com> wrote: > >> Booting on s390x is a little bit different compared to other architectures. >> Let's add some information for people who are not yet used to this. >> >> Signed-off-by: Thomas Huth <th...@redhat.com> >> --- >> docs/system/s390x/bootdevices.rst | 82 +++++++++++++++++++++++++++++++ >> docs/system/target-s390x.rst | 1 + >> 2 files changed, 83 insertions(+) >> create mode 100644 docs/system/s390x/bootdevices.rst >> >> diff --git a/docs/system/s390x/bootdevices.rst >> b/docs/system/s390x/bootdevices.rst >> new file mode 100644 >> index 0000000000..68f0ffd450 >> --- /dev/null >> +++ b/docs/system/s390x/bootdevices.rst >> @@ -0,0 +1,82 @@ >> +Boot devices on s390x >> +===================== >> + >> +Booting with bootindex parameter >> +-------------------------------- >> + >> +For classical mainframe guests (i.e. LPAR or z/VM installations), you always >> +have to exactly specify the disk where you want to boot from (or "IPL" from, > > s/exactly/explictly/ ?
Or "to explicit the disk ..."? > >> +in s390x-speak -- IPL means "Initial Program Load"). Especially, there can > > s/Especially/In particular/ ? > >> +also be only one boot device according to the architecture specification, >> thus >> +specifying multiple boot devices is not possible (yet). >> + >> +So for booting an s390x guest in QEMU, you should always mark the >> +device where you want to boot from with the ``bootindex`` property, for >> +example:: >> + >> + qemu-system-s390x -drive if=none,id=dr1,file=guest.qcow2 \ >> + -device virtio-blk,drive=dr1,bootindex=1 >> + >> +For booting from a CD-ROM ISO image (which needs to include El-Torito boot >> +informatin for being bootable), it is recommended to specify a ``scsi-cd`` > > s/informatin for being/information in order to be/ > >> +device, for example like this:: >> + >> + qemu-system-s390x -blockdev file,node-name=c1,filename=... \ >> + -device virtio-scsi \ >> + -device scsi-cd,drive=c1,bootindex=1 >> + >> +Note that you really have to use the ``bootindex`` property to select the >> +boot device. The old-fashioned ``-boot order=...`` command of QEMU (and >> +also ``-boot once=...``) is not supported on s390x. > > (...) > > This looks good to me, and is certainly helpful. I can fix the nits > myself and apply it. > > There's also some documentation regarding DASD IPL in the devel guide; > but as that is mostly helpful for people actually working with the > code, I don't think that it makes sense to cross-reference it. > >
