It's already possible to do a network boot of an s390x guest with an external netboot image based on a Linux installation, but it would be much more convenient if the s390-ccw firmware supported network booting right out of the box, without the need to assemble such an external image first.
This patch series now introduces a s390-netboot.img that can be used for network booting via DHCP and TFTP by re-using the networking stack from the SLOF firmware (see https://github.com/aik/SLOF/ for details), and adds a driver for virtio-net-ccw devices. The code can only be built if the roms/SLOF/ submodule has been checked out, and you apply the following pending SLOF patch on top of it: https://patchwork.ozlabs.org/patch/785384/ Then it should be possible to download a combined kernel + initrd image via TFTP, e.g. by starting QEMU with: qemu-system-s390x ... -device virtio-net,netdev=n1,bootindex=1 \ -netdev user,id=n1,tftp=/path/to/tftp,bootfile=kernel.img Note that this version does not support downloading via config files (i.e. pxelinux config files or .INS config files) yet. This will be added later. v2: - Put the network boot loader into a separate s390-netboot.img binary instead of linking it directly into the s390-ccw firmware. - Use the SLOF sources from the roms/SLOF/ submodule instead of copying them into the pc-bios/s390-ccw folder - Removed the .INS config file loading code for now - only support combined kernel + initrd images in this initial implementation. Thomas Huth (8): pc-bios/s390-ccw: Move libc functions to separate header pc-bios/s390-ccw: Move ebc2asc to sclp.c pc-bios/s390-ccw: Move virtio-block related functions into a separate file pc-bios/s390-ccw: Add a write() function for stdio roms/SLOF: Update submodule to latest status pc-bios/s390-ccw: Add core files for the network bootloading program pc-bios/s390-ccw: Add virtio-net driver code pc-bios/s390-ccw: Link libnet into the netboot image and do the TFTP load pc-bios/s390-ccw/Makefile | 13 +- pc-bios/s390-ccw/bootmap.c | 1 + pc-bios/s390-ccw/libc.h | 43 +++++ pc-bios/s390-ccw/main.c | 14 +- pc-bios/s390-ccw/netboot.mak | 51 ++++++ pc-bios/s390-ccw/netmain.c | 365 +++++++++++++++++++++++++++++++++++++++++ pc-bios/s390-ccw/s390-ccw.h | 31 +--- pc-bios/s390-ccw/sclp.c | 37 +++-- pc-bios/s390-ccw/virtio-blk.c | 296 +++++++++++++++++++++++++++++++++ pc-bios/s390-ccw/virtio-net.c | 130 +++++++++++++++ pc-bios/s390-ccw/virtio-scsi.c | 1 + pc-bios/s390-ccw/virtio.c | 283 ++------------------------------ pc-bios/s390-ccw/virtio.h | 17 +- roms/SLOF | 2 +- 14 files changed, 955 insertions(+), 329 deletions(-) create mode 100644 pc-bios/s390-ccw/libc.h create mode 100644 pc-bios/s390-ccw/netboot.mak create mode 100644 pc-bios/s390-ccw/netmain.c create mode 100644 pc-bios/s390-ccw/virtio-blk.c create mode 100644 pc-bios/s390-ccw/virtio-net.c -- 1.8.3.1
