Hello. to try to compile the correct freebsd kernel that's recognized by xen using the Elliott Michell code, are the commands below the correct ones ?
$ truncate -s 100G xenvm.img $ mdconfig -f xenvm.img -u 0 $ newfs /dev/md0 $ mount /dev/md0 /mnt $ git clone https://gitlab.com/ehem/freebsd-src.git $ cd freebsd-src $ make -DNO_MODULES KERNCONF=GENERIC TARGET=arm TARGET_ARCH=armv7 buildkernel $ echo "/dev/xbd0 / ufs rw 1 1" > /mnt/etc/fstab $ nano /build/etc/ttys (add the line 'xc0 "/usr/libexec/getty Pc" xterm on secure") $ umount /build $ mdconfig -d -u 0 Do you see errors ? some missing ? very thanks. On Tue, Nov 28, 2023 at 3:28 AM Stefano Stabellini <sstabell...@kernel.org> wrote: > On Mon, 27 Nov 2023, Chuck Zmudzinski wrote: > > On 11/27/2023 10:22 AM, Chuck Zmudzinski wrote: > > > On 11/27/2023 7:45 AM, Mario Marietto wrote: > > >> @Chuck Zmudzinski <mailto:brchu...@netscape.net> : Stay tuned. They > want to help us. The xen developers are great. Very good support for us. > I'm sure that you can give a good contribution to understand what's our > problem and how to implement a fix with the help of all those good guys. > > >> > > >> On Mon, Nov 27, 2023 at 11:56 AM Roger Pau Monné < > roger....@citrix.com <mailto:roger....@citrix.com>> wrote: > > >> > > >> On Mon, Nov 27, 2023 at 10:28:13AM +0000, Henry Wang wrote: > > >> > +(xen-devel and Arm maintainers, including Julien) > > >> > > > >> > > On Nov 27, 2023, at 18:03, Mario Marietto < > marietto2...@gmail.com <mailto:marietto2...@gmail.com>> > > >> > > wrote: > > >> > > > > >> > > Hello. We have just virtualized Debian 12 on our arm (32 bit) > > >> > > Chromebook model xe303c12 . As host / dom0 we have chosen > Devuan > > >> > > 5,and for guest / domU,Debian 12. It works great. But our > goal is > > >> > > different. We want to virtualize FreeBSD as domU. Can we have > a > > >> > > working Xen PV network driver for a FreeBSD arm guest ?. I > found > > >> > > that Julien Grall has ported the Xen drivers to FreeBSD on > arm. I > > >> > > would like to know if Julien's work was accepted upstream by > > >> > > FreeBSD, in which case FreeBSD as a Xen guest on arm should > work > > >> > > if we enable the Xen PV drivers in the FreeBSD on arm kernel. > If > > >> > > Julien's work was not accepted upstream by FreeBSD, we will > have > > >> > > to find his patches and apply them ourselves to the FreeBSD > on arm > > >> > > kernel. > > >> > > >> I've added Elliot on Cc as he is working on upstreaming the > patches to > > >> FreeBSD. He will be able to provide a better update than myself. > > >> > > >> Regards, Roger. > > > > > > I have been collaborating with Mario, and I can explain what we have > done so far : > > > > > > We are using Julien's patch set against an old development version of > FreeBSD 11 > > > from 2014-12-03 : > > > > > > > https://xenbits.xen.org/gitweb/?p=people/julieng/freebsd.git;a=shortlog;h=refs/heads/xen-arm-v2.2 > > > > > > We successfully built the XENVIRT kernel and FreeBSD world, and > created the > > > FreeBSD rootfs according to Julien's instructions here : > > > > > > > https://lists.freebsd.org/pipermail/freebsd-xen/2014-November/002202.html > > > > > > There were some adjustments to the instructions : > > > > > > To build the kernel, we used : > > > > > > $ sudo make TARGET_ARCH=armv6 KERNCONF=XENVIRT buildkernel > > > > > > instead of > > > > > > $ sudo make TARGET_ARCH=armv6 KERNCONF=XENHVM buildkernel > > > > > > The FreeBSD 'kernel' file is in ELF format and did not work, and we > spent > > > some time trying to convert it to the zImage format without realizing > the > > > build of the FreeBSD kernel creates the 'kernel.bin' file in the > zImage format. > > > So when booting with the 'kernel.bin' file instead, it actually boots : > > > > > > user@devuan-bunsen ~ % sudo xl create freebsd.cfg > > > Parsing config from freebsd.cfg > > > user@devuan-bunsen ~ % sudo xl li > > > Name ID Mem VCPUs State > Time(s) > > > Domain-0 0 768 2 r----- > 1439.4 > > > freebsd 1 1152 1 r----- > 3.0 > > > user@devuan-bunsen ~ % > > > > > > However, the guest is still not working correctly : > > > > > > 1. Attaching the console with the -c option at creation or with > > > 'xl console freebsd' results in no output to the console. > > > > > > 2. The timestamp on the virtual disk image file shows that the > filesystem > > > was at best mounted read-only, if it was mounted at all by the guest > > > FreeBSD kernel. > > > > > > 3. The 'xl shutdown freebsd' command does not work, it just hangs. To > stop > > > the guest, you need to do 'xl destroy freebsd'. > > > > > > However, I think we can get the console to work and the rootfs to > mount because I > > > just realized I forgot to do the steps from Julien's instructions of > editing the > > > /etc/fstab and /etc/ttys files in the FreeBSD rootfs : > > > > > > $ echo "/dev/xbd0 / ufs rw 1 1" > > /mnt/etc/fstab > > > $ vi /mnt/etc/ttys (add the line 'xc0 "/usr/libexec/getty Pc" xterm on > secure") > > > > > > I will add those and see if the console and disk are working. > > > > Unfortunately, adding xc0 to /etc/ttys and /dev/xbd0 as the root device > in > > /etc/fstab did not make the console or disk work. Still no output on the > > xen console from the guest kernel, and the timestamp on the rootfs image > > file did not change so it did not mount read-write. > > > > We could use some advice for troubleshooting this. Now, we are blind > because > > we are not getting any xen console output But I am pleased we were able > to > > demonstrate that Julien's old patch set for FreeBSD 11 allows us to boot > > FreeBSD 11 on a modern version of Xen on arm - we are using the Debian > > stable Xen 4.17 packages. > > You can use the DEBUG hypercalls to check how far we got into the > booting process: > https://wiki.xenproject.org/wiki/Xen_ARM_DEBUG_hypercalls > > For instance add the following to FreeBSD code: > > asm volatile("hvc 0xfffd"); > > -- Mario.
