PReP/40p updates

Sent the qemu patches for the upstream review. Also fixed a couple of issues in OFW: clock rush and interrupt routing for the PCNet (it still used interrupt 13, which was correct in 2017, but has been changed meanwhile).

Will update the links in the how-to shortly.

/Stay tuned

The next How-To

Nearly 10 years after writing Solaris/SPARC under QEMU How-To, now it’s time for the AIX/PReP under QEMU How-To.

Back then my strategy was using the Power-On Self Tests and other tests from the original firmware to verify and improve qemu-system-sparc.

This time I took a different approach as some tests are synthetic and check some typical hardware-specific problems like broken and shorted wires or faulty memory chips. The result of IBM firmware diagnostics is something like “replace your motherboard” – which is not exactly helpful to find out for instance whether there is a problem with the interrupt or DMA emulation. And yeah, there are some problems with the DMA emulation, that’s why qemu-system-ppc -M 40p can not use IDE CD-ROMs under AIX, and probably some other DMA devices like sound card (haven't tried it yet).

The approach this time was making the emulation good enough and describe it the way that it

• matches to the hardware implemented in QEMU good enough
• has a driver in AIX

The later was tricky, as AIX does support only a very limited amount of hardware. It checks exactly that your IDE controller is from Winbond (does anyone still remember them?) and checks the exact chip model. It doesn’t care if your chip is compatible, it wants the exact match.

As result we have a -M 40p model in QEMU which is not perfectly matching the physical IBM PPS 6015, and a firmware which describes it the way AIX 5.1 can see the onboard devices.

But anyways, it was fun 10 years ago and it's still fun.

AIX/PReP under QEMU How-To

AIX/PReP under QEMU How-To

Fetch the 40p-20190406-aix-boots branch and  compile qemu-system-ppc:

configure --target-list=ppc-softmmu

download the OFW image q40pofw-serial.rom configured  for the serial line.

create an empty hard disk image:

qemu-img create -f qcow2 aix-hdd.qcow2 8G

Concerning the VGA graphics: OFW can utilize the S3-Trio emulation done by Hervé, but AIX 5.1 can’t use it yet. For now, the serial line rules, but if you feel adventurous you can try using it omitting  the -vga none -nongraphic part.

qemu-system-ppc -M 40p -bios q40pofw-serial.rom -serial telnet::4441,server -hda aix-hdd.qcow2 -cdrom
/path/to/aix-5.1-cd1.iso  -vga none -nographic

Then in another terminal window:

telnet localhost 4441

The following text will appear:

QEMU PReP/40p, Serial #0, 128 MiB memory installed
Open Firmware, built  April 06, 2019 17:47:55
Copyright (c) 1995-2000, FirmWorks.
Copyright (c) 2014,2017,2019 Artyom Tarasenko.

Type any key to interrupt automatic startup
Boot device: /pci/ethernet  Arguments: 
The DHCP server did not specify a boot server

Boot load failed

ok

Once you see the “ok” prompt, type

ok boot cdrom:2

 

Then be patient, it takes some minutes till the first greeting appears and then some more before the installer starts.

Then answerer the installer questions. On my machine the copy process takes nearly one hour. At 93% it stalls after installing “mtools” for something like 10 Minutes, and then for another 10 minutes after “FAILURES” section, but don’t panic, eventually it will continue.

Once the install is done the emulated machine reboots to the “ok” prompt again. Type

ok boot disk

Supported AIX versions

I tested it with AIX 5.1 only. In theory it might work with 4.3.3 – 5.1 (a smoke test shows that at least the installer does start with AIX 4.3.3), let me know if you tested it. The 6015 support was officially discontinued in AIX 5.2, and probably the corresponding drivers were removed. I haven’t looked it up, as I don’t have a 5.2 media.

Networking in AIX 4.3.3 - 5.1 under QEMU

It looks like the PCNet driver (aka kent) is broken in AIX. I think the "busio" value used to look different in the previous versions. The networking can still be set up though. After performing the install, login as root and do the following (^D and ^C are Control-D and Control-C respectively):

# cat > lance-chg.asc
CuAt:
        name = "ent0"
        attribute = "busio"
        value = "0x01000000"
        type = "O"
        generic = "D"
        rep = "nr"
        nls_index = 3
^D
# odmchange -o CuAt -q "name=ent0 and attribute=busio" lance-chg.asc
# rmdev -l ent0
# mkdev -l ent0
# ifconfig en0 10.0.2.15
# ping 10.0.2.2
PING 10.0.2.2: (10.0.2.2): 56 data bytes
64 bytes from 10.0.2.2: icmp_seq=0 ttl=255 time=4 ms
64 bytes from 10.0.2.2: icmp_seq=1 ttl=255 time=3 ms
^C
#

If you try it with adifferent AIX version, before changing the busio, check first whether you have to modify it:

odmget -q "name=ent0 and attribute=busio" CuAt

In case  you get

value = "0x01000000"

you don't have to change it.

Your feedback is welcome!

Last updated on 2020.02.07

Debian/sparc64 Wheezy under QEMU How-To

The steps to install Debian Wheezy RC1 / SPARC64 under QEMU.

Since the installation process is not obvious for the current QEMU and Debian versions, I gathered this How-To. Feel free to send any feedback.

Booting Linux/sparc64 on todays OpenBIOS

Historical day for everyone interested in the vanilla qemu-system-sparc64 emulator. For the first time it can boot Linux!

Although the patches I sent upstream are  fixing CPU and IOMMU, there is still one missing piece: cmd646 IDE. Luckily it's not a showstopper at all: qemu-sparc64 is a PCI machine, which means one could use the fast virtio instead! Now, this is the command line:

$  sparc64-softmmu/qemu-system-sparc64 -m 256 -nographic -prom-env 'auto-boot?=false' -kernel /path/to/kernel/image -drive file=/path/to/debian-disk,if=virtio,index=0 -append 'root=/dev/vda1 init=/bin/sh'

Some time ago, I used Forth to workaround missing qemu features  to get OBP working.
Now it's pretty similar: OpenBIOS doesn't have all the properties necessary for Linux to get the interrupt mapping.

So at the ok command prompt where you'd get after the command above, type:
 
cd /
1 encode-int " #interrupt-cells" property
cd /pci@1fe,0/ebus
000001fe encode-int 020003f8 encode-int encode+ 1 encode-int encode+
ffe29140 encode-int encode+ 2b encode-int encode+ " interrupt-map" property
000001ff encode-int ffffffff encode-int encode+ 00000003 encode-int encode+
" interrupt-map-mask" property

cd /pci@1fe,0/ebus@3/su
1 encode-int " interrupts" property
cd /pci@1fe,0/pci-ata@5
0 encode-int " interrupts" property

cd /pci@1fe,0/pci1af4,1001
0 encode-int " interrupts" property
device-end
boot


The only magical constant above is actually "ffe29140" - the address of the root pci node in the OpenBIOS device hierarchy. Although it the same in all the recent builds, in theory it could be moved somewhere else one day. But I guess till that day OpenBIOS will have the missing properties... ;-)

Update:

Oh, and a few words to /path/to/kernel/image and /path/to/debian-disk:

I found no Linux/sparc64 distribution which has a built in virtio driver. This makes installing from a  CD/DVD image not possible. The solution is build your own kernel with the virtio driver compiled in and put it at /path/to/kernel/image.

As for the disk, the user space utilities from the sparc32 world can be used in the sparc64 world as is. So, you can install Debian (or your favorite sparc32 distribution) in the /path/to/debian-disk, using qemu-system-sparc (no 64 at the end), and then use it with qemu-system-sparc64 as described above.

If you know a Linux/sparc64 distribution with the virtio support, please let me know.

/Happy hacking

sent another qemu patch upstream

The -m 256 option should be not necessary anymore. The minimal RAM amount for the emulated SPARCStation-5 is now 32 MiB. So OBP should understand now the memory sizes of 32, 64, 96, 128, 160,192, 224 and 256 MiB. When not specified, the default value of 128 MiB is taken.

The support of RAM size <256MiB is important for SunOS 4.1.4 (aka Solaris 1.1.2) because its installer crashes under qemu when started with "-m 256" option.

Will update the how-to shortly.

Happy 2010

I'm back from skiing. Happy 2010 everyone!

Updated the Solaris under qemu how-to, added launching instructions for the Solaris versions prior 2.6.

Meanwhile I'm working on the MMU emulation problems. It's harder than it looked. There is a documentation on the SuperSPARC Multi Cache Controller, which describes, what MMU does in a case of a double fault differently than it is currently implemented in qemu. Unfortunately it looks like either it describes it wrong, or I don't get what is written there (yes, I've seen it says "Subject to Change Without Notice" in the footer). At least I can not confirm the described behavior on the real SS-20.

So, there are 3 variants of the MMU behavior: qemu's, described, and the correct one. I'm exploring the last two to fix the first one.

Solaris/sparc under qemu how-to

This document attempts to answer basic questions on how to set up qemu-system-sparc so that it can boot Solaris. The current version of this how-to is available under http://tyom.blogspot.com/2009/12/solaris-under-qemu-how-to.html. The emulation of sparc system is still being improved, so this document will probably be updated.

Disclaimer

Reading, understanding and using the Howto is by no means a guarantee for successfully finishing the task, and any mechanical failure, accident, psychological trauma or other cataclysm that may result from using the Howto is entirely your own responsibility and liability.

List of supported Solaris versions

Currently the versions 1.1.2 (SunOS 4.1.4), 2.2 (SunOS 5.2), 2.3 (SunOS 5.3), 2.4 (SunOS 5.4), 2.5.1 (SunOS 5.5.1), 2.6 (SunOS 5.6), 7 (SunOS 5.7), 8 (SunOS 5.8) and 9 (SunOS 5.9) are supported.

Kernel debugger (kadb) can be loaded for the versions 1.1.2 (from a HDD image) and 2.2 - 9 (from a HDD image or an install CD/DVD).

Solaris 10 and OpenSolaris do not support 32 bit SPARC platforms, so they can never be booted under qemu-system-sparc. (Some day they maybe will be booted under qemu-system-sparc64 though).
The versions prior 1.1.1 and 2.0-2.1 do not support SPARCstation-5 or SPARCstation-20, so they can not be booted. The version 2.2 can be booted in the SPARCstation-20 emulation mode only (the exact steps are not yet described in this howto).

The version 1.1.1 is not yet tested. Reports or/and boot disks are welcome.

List of supported Firmware versions

OpenBIOS 1.0+ can boot some Solaris versions. Please, try it first, and if doesn't work for you, send reports to the OpenBIOS mailing list.

The proprietary OpenBoot PROM (OBP) can boot all the Solaris versions available for the sun4m architecture (see the previous chapter). The SPARCstation-5 OBP versions 2.15 and 2.29 are known to work. The SPARCstation-20 revisions 2.15, 2.22 and 2.25 work only for some guest CPU models. If you have tested other OBP versions please let me know.

Compiling qemu-system-sparc

The qemu version 0.13+ is capable of booting some Solaris versions. In order to run Solaris 2.6+, a QEMU 2.5.91+ (April the 12th, 2016) is required. Indeed, some bugfixes or features are only included in the "bleeding edge", a.k.a git master. Compiling master is straightforward:

git clone git://git.qemu.org/qemu.git
mkdir -p qemu/build
cd qemu/build
../configure --target-list=sparc-softmmu
make

Launching qemu with OpenBIOS to boot from a cdrom image

As of today (svn.r1246) OpenBIOS can boot the following Solaris versions:

SunOS Release 5.7 Version Generic_106541-02
SunOS Release 5.7 Version Generic_106541-08
SunOS Release 5.8 Version Generic_108528-09 32-bit
SunOS Release 5.8 Version Generic_108528-29 32-bit
SunOS Release 5.9 Version Generic_112233-10 32-bit
SunOS Release 5.9 Version Generic_118558-34 32-bit

Launch command:
sparc-softmmu/qemu-system-sparc -M SS-5  -nographic -prom-env 'auto-boot?=false' -cdrom Solaris8.iso


The option -prom-env 'auto-boot?=false' is optional. It allows specifying Solaris boot options, like -v and/or -s and/or -b. If no boot options are required, the command line option -boot d can be used instead.

The option -nographic is handy, because the emulated default graphic card (TCX) is not compatible with Solaris X-Window system. Nevertheless it can be omitted when booting in text console (e.g. single user mode, or installation without X-Window).

If the option -prom-env 'auto-boot?=false' is used, type
 boot cdrom:d -v
at the "0 >" prompt.

The versions known to boot with OBP, but not with OpenBIOS:

SunOS Release 4.1.4 (MUNIX)
SunOS Release 5.2 Version Generic
SunOS Release 5.3 Version Generic
SunOS Release 5.4 Version Generic
SunOS Release 5.5.1 Version Generic
SunOS Release 5.6 Version Generic

Launching qemu with OBP to boot from a cdrom image

Solaris 2.6 and above:

sparc-softmmu/qemu-system-sparc -M SS-5  -bios /path/to/ss5.bin -nographic -cdrom Solaris2.6.iso

Solaris 2.5.1 and earlier:

sparc-softmmu/qemu-system-sparc -M SS-5 -startdate "2009-12-13" -bios /path/to/ss5.bin -nographic -hdb Solaris2.5.1.iso

The option -startdate "2009-12-13" is necessary for the older QEMU versions, which have the y2010 bug. It's not necessary for QEMU 1.2+.

The option -nographic is handy, because the emulated default graphic card (TCX) is not compatible with Solaris X-Window system. Nevertheless it can be omitted when booting in text console (e.g. single user mode, or installation without X-Window).

Successfully initialized OBP should print lines like this:

SPARCstation 5, No Keyboard

...

Type help for more information

ok

booting Solaris in a single user mode from a CD-ROM
at the ok prompt:

Solaris 2.6+:

boot disk2:d -vs

Solaris 2.5.1-:

boot disk1:d -vs

booting Solaris kernel debugger from a CD-ROM
at the ok prompt:

Solaris 2.6+:

boot disk2:d kadb -kdv
Solaris 2.5.1-:

boot disk1:d kadb -kdv
If you are going to debug the kernel, I recommend you to read the PANIC! UNIX System Crash Dump Analysis Handbook. The kernel debugger is a really powerful tool and the book helped me a lot to learn how to use it and shed a lot of light on Solaris internals.

booting Solaris from a HDD image
To be able to boot from a hdd image, add the following line to the /etc/system on the hard drive:
set scsi_options=0x58

Normally during the Solaris installation process the hard drive is mounted under /a, so it can be done with

# cat >> /a/etc/system

set scsi_options=0x58

^d

right after the installation. Hence it's recommended to switch off the automatic reboot  option when the installer asks for it.

If the steps above are not performed, the HDD boot fails with the error message:
cannot mount root on /iommu@0, 10000000/sbus@0, 10001000/espdma@5, 8400000/esp@5, 8800000/sd@0,0

Comments & reports are welcome. Here and at the qemu-devel mailing list.

Last updated on 11.04.2016.

/Happy hacking

Solaris/sparc under qemu

My next project is launching Solaris/sparc under qemu.

Sparc v9 (sun4u) is just not ready yet, but sparc v8 (sun4m) emulation is there since years, so there are good chances to get some luck with Solaris 9 - the last Solaris version which supports 32 bit machines. Alas, no OpenSolaris.

update: I gathered a Solaris/SPARC under qemu how-to.