Re: or1k -M virt -hda and net.

[Stafford Horne <shorne@gmail.com>]

On Sun, Dec 22, 2024 at 11:29:19AM -0600, Rob Landley wrote:
> On 11/24/24 00:50, Stafford Horne wrote:
> > > Speaking of which, is there a way to get or1k to exit the emulator? I told
> > > the kernel to reboot but it says "reboot failed, system halted" and hangs
> > > instead of exiting qemu. (My testroot runs qemu under "timeout -i 10" to
> > > kill it after 10 seconds of inactivity, I.E. nothing written to stdout, but
> > > it still counts as a failure on one of the criteria.)
> > 
> > With the or1k-sim board it is not possible.  Traditionally on or1k we use
> > special NOP instructions to reboot simulators i.e. 'l.nop 1'.  The QEMU team was
> > not happy to support this mechanism.
> > 
> >    https://lore.kernel.org/openrisc/fb69c137317a365dcb549dfef1ecd2fbff48e92c.1492384862.git.shorne@gmail.com/T/#mef76d30d294aed84548b1e0d3e23aae499deaeec
> > 
> > As an alertnative we can use the 'virt' board which supports shutdown and
> > restart via the generic syscon drivers.
> > 
> >      $ grep -C1 SYSCON arch/openrisc/configs/virt_defconfig
> >      CONFIG_POWER_RESET=y
> >      CONFIG_POWER_RESET_SYSCON=y
> >      CONFIG_POWER_RESET_SYSCON_POWEROFF=y
> >      CONFIG_SYSCON_REBOOT_MODE=y
> >      # CONFIG_HWMON is not set
> 
> I built the 6.12 ARCH=openrisc virt_defconfig and got it to boot my
> initramfs, but while it does shut down, it hasn't got network or block
> device support.
> 
> The kernel config looks like it should have virt block device support, but
> nether -hda README nor "-drive file=README,format=raw,id=hd0 -device
> virtio-blk-device,drive=hd0" seem to be wiring it up in qemu where the
> kernel can find it?

The default virt_defconfig should have the drivers we need.  The OpenRISC virt
platform supports PCI and virtio devices, so I select many of the related
drivers.

    $ grep -C1 -e PCI -e VIRT arch/openrisc/configs/virt_defconfig
    # CONFIG_WIRELESS is not set
    CONFIG_PCI=y
    CONFIG_PCIEPORTBUS=y
    CONFIG_PCI_HOST_GENERIC=y
    CONFIG_DEVTMPFS=y
    --
    CONFIG_BLK_DEV_NBD=y
    CONFIG_VIRTIO_BLK=y
    CONFIG_NETDEVICES=y
    CONFIG_VIRTIO_NET=y
    CONFIG_ETHOC=y

In my qemu startup I wire in the hard drive and network in my qemu start script:

 - https://github.com/stffrdhrn/or1k-utils/blob/master/scripts/qemu-or1k-linux

This uses:

  -device virtio-net-pci,netdev=user -netdev user,id=user,net=$IPRANGE.1/24,host=$IPRANGE.100
  -device virtio-blk-device,drive=d0 -drive file=${DISK},id=d0,if=none,format=qcow2

> Haven't tried to get fancy with the network yet. The buildroot config is
> still or1ksim...

Yeah, its nothing fancy for me either. The buildroot with systemV init scripts
get everything working for me.

-Stafford