[PATCH 0/2] m68k: Add Virtual M68k Machine

[Laurent Vivier <laurent@vivier.eu>]

The most powerful m68k machine emulated by QEMU is a Quadra 800,
but this machine is very limited: only 1 GiB of memory and only some
specific interfaces, with no DMA.

The Virtual M68k Machine is based on Goldfish interfaces defined by Google
for Android simulator. It uses Goldfish-rtc (timer and RTC),
Goldfish-pic (PIC) and Goldfish-tty (for early tty).

The machine is created with 128 virtio-mmio buses, and they can
be used to add serial console, GPU, disk, NIC, HID, hwrng, 9PFS...

The virtual m68k machine has been merged in QEMU and will be available
with the release 6.0.

This series introduces the support of this new machine in the linux kernel.

If you want to try:

- Configure and build latest QEMU with (or download qemu 6.0 binary):

  .../configure --target-list=3Dm68k-softmmu --enable-virglrenderer
  make

- Configure and build linux with:

  make virt_defconfig
  make vmlinux

A pre-installed qcow2 disk image is available at:

http://vivier.eu/debian-10.0.qcow2

You can run the machine with something like:

qemu-system-m68k -M virt \
  -m 3G \
  -chardev stdio,signal=3Doff,mux=3Don,id=3Dchar0 \
  -mon chardev=3Dchar0,mode=3Dreadline \
  -kernel vmlinux \
  -append "console=3Dhvc0 root=3D/dev/vda2" \
  -blockdev node-name=3Dsystem,driver=3Dfile,filename=3Ddebian-10.0.qcow2 \
  -blockdev node-name=3Ddrive0,driver=3Dqcow2,file=3Dsystem \
  -device virtio-blk-device,drive=3Ddrive0 \
  -serial chardev:char0 \
  -device virtio-net-device,netdev=3Dhostnet0 \
  -netdev bridge,id=3Dhostnet0,br=3Dvirbr0,helper=3D/usr/libexec/qemu-bridge-=
helper \
  -device virtio-serial-device \
  -device virtio-gpu-device \
  -device virtconsole,chardev=3Dchar0 \
  -device virtio-keyboard-device \
  -device virtio-mouse-device

You can watch a presentation about the machine on the Planet m68k channel:

    https://youtu.be/s_ve0bCC9q4
    [Demo at 38:00]

Thanks,
Laurent

Laurent Vivier (2):
  rtc: goldfish: remove dependency to OF
  m68k: introduce a virtual m68k machine

 arch/m68k/Kbuild                           |   1 +
 arch/m68k/Kconfig.machine                  |  17 +++
 arch/m68k/configs/virt_defconfig           |  93 ++++++++++++++++
 arch/m68k/include/asm/irq.h                |   3 +-
 arch/m68k/include/asm/pgtable_mm.h         |   7 ++
 arch/m68k/include/asm/setup.h              |  44 ++++++--
 arch/m68k/include/asm/virt.h               |  26 +++++
 arch/m68k/include/uapi/asm/bootinfo-virt.h |  18 ++++
 arch/m68k/include/uapi/asm/bootinfo.h      |   1 +
 arch/m68k/kernel/Makefile                  |   1 +
 arch/m68k/kernel/head.S                    |  30 ++++++
 arch/m68k/kernel/setup_mm.c                |   9 ++
 arch/m68k/mm/kmap.c                        |  20 ++--
 arch/m68k/virt/Makefile                    |   6 ++
 arch/m68k/virt/config.c                    | 118 +++++++++++++++++++++
 arch/m68k/virt/ints.c                      | 110 +++++++++++++++++++
 arch/m68k/virt/platform.c                  |  80 ++++++++++++++
 arch/m68k/virt/timer.c                     |  91 ++++++++++++++++
 drivers/rtc/Kconfig                        |   2 +-
 19 files changed, 659 insertions(+), 18 deletions(-)
 create mode 100644 arch/m68k/configs/virt_defconfig
 create mode 100644 arch/m68k/include/asm/virt.h
 create mode 100644 arch/m68k/include/uapi/asm/bootinfo-virt.h
 create mode 100644 arch/m68k/virt/Makefile
 create mode 100644 arch/m68k/virt/config.c
 create mode 100644 arch/m68k/virt/ints.c
 create mode 100644 arch/m68k/virt/platform.c
 create mode 100644 arch/m68k/virt/timer.c

--=20
2.30.2