On 02/20/2017 04:33 PM, Thomas Huth wrote: > On 20.02.2017 15:19, Cornelia Huck wrote: >> From: Farhan Ali <al...@linux.vnet.ibm.com> >> >> The current QEMU ROM infrastructure rejects late loading of ROMs. >> And ELFs are currently loaded as ROM, this prevents delayed loading >> of ELFs. So when loading ELF, allow the user to specify if ELF should >> be loaded as ROM or not. >> >> If an ELF is not loaded as ROM, then they are not restored on a >> guest reboot/reset and so its upto the user to handle the reloading. > > Could you maybe also explain here why you need such a delayed ELF > loading? Why can't you load the s390-netboot.img at the same time as > s390-ccw.img?
Please read the cover letter for some details how to build such a netrom. This is a simple variant to implement a standard compliant network boot today but using a kernel+busybox+scripts. Long term we certainly want to have a look at implementing something in the ccw bios, but this (tcp stack, virtio net, etc) will take some (a lot?) more time. Having a ramdisk+kernel loaded all the time would be extremely wasteful. This patch (1) has another advantage. Right now we load the ccw bios all the time, even for -kernel xxx boot, to allow the guest user to use chreipl to reboot from a disk. With this in place we can rework our ccw bios loader to load the ccw bios lazily as well. Christian
