Re: [Qemu-devel] [PATCH 0/6] ppc: add a IBM 40p machine (RS/6000, PReP)

[Thomas Huth <thuth@redhat.com>]

On 13.01.2017 13:23, Mark Cave-Ayland wrote:
> On 12/01/17 12:57, Hervé Poussineau wrote:
> 
>> Le 11/01/2017 à 17:58, Artyom Tarasenko a écrit :
>>> Hi Hervé,
>>>
>>> nice work!
>>>
>>> On Thu, Dec 29, 2016 at 11:12 PM, Hervé Poussineau
>>> <hpoussin@reactos.org> wrote:
>>>> Hi,
>>>>
>>>> This patchset adds the emulation of the IBM RS/6000 7020 (40p). The
>>>> real machine is
>>>> able to run AIX (up to 4.3.3), Windows NT (up to 4.0 SP1), the beta
>>>> of OS/2 PowerPC,
>>>> Solaris, Linux, NetBSD/PReP ...
>>>>
>>>> I've tested current emulation with Open Hack'Ware, OpenBIOS and
>>>> official firmware.
>>>>
>>>> Linux kernel starts, and freezes during boot (like with 'prep' machine).
>>
>> I already saw a regression during 2.7.0 cycle with 603 CPU. However, I
>> was unable to provide kernel source, so Benjamin was unable to find the
>> problem.
>> http://lists.gnu.org/archive/html/qemu-devel/2016-08/msg03760.html
>>
>>>
>>> If prep can't do it anymore, it looks like a regression. I definitely
>>> remember seen a sitting penguin and a login prompt ~ 2 years ago. At
>>> least with OFW.
>>>
>>>> Windows NT starts up to the point where it wants to change endianness.
>>>
>>> I hit that with Solaris/PPC a few years back as you published your
>>> previous attempt. Do you know what is missing? I guess CPU endianness
>>> switch emulation is working because it is used in the newer POWER
>>> CPUs. Is it just the systemIO which has to be improved, or is it more?
>>
>> Yes, PReP System I/O has LE flag which is not implemented.
>> You may be interested by
>> ftp://ftp.software.ibm.com/rs6000/technology/spec/endian.ps
>> which deals about endianness switching, with some code from Windows NT/PPC
>>
>>>
>>>> Other OSes have not been tested.
>>>>
>>>> This machine is a superset of the 'prep' one, because we know exactly
>>>> what is/should
>>>> emulated, and that operating system list running on it is quite wide.
>>>> I hope that 'prep' machine can be deprecated soon and then later
>>>> removed.
>>>
>>> Would be nice to keep 'prep' until the 40p can boot Linux and NetBSD
>>> 6.1.3 (this version used to work with -M prep last time I checked).
>>
>> Some Linux kernels seem to work, some other ones seem to not work (hang
>> while booting)
>> I've not searched why.
>>
>> I tried NetBSD 6.1.3/PReP.
>> cdroms/harddisks don't boot anymore with Open Hack'Ware since some
>> changes in IDE core
>> Kernel boots better with 40p than with prep
>>
>> ====================================================
>> prep:
>>
>> Copyright (c) 1996, 1997, 1998, 1999, 2000, 2001, 2002, 2003, 2004, 2005,
>>     2006, 2007, 2008, 2009, 2010, 2011, 2012
>>     The NetBSD Foundation, Inc.  All rights reserved.
>> Copyright (c) 1982, 1986, 1989, 1991, 1993
>>     The Regents of the University of California.  All rights reserved.
>>
>> NetBSD 6.1.3 (INSTALL)
>> Model: Qemu
>> total memory = 128 MB
>> avail memory = 119 MB
>> panic: call to null-ptr from 0x0
>>
>> The operating system has halted.
>> Please press any key to reboot.
>>
>> ====================================================
>> 40p/Open Hack'Ware:
>>
>> Copyright (c) 1996, 1997, 1998, 1999, 2000, 2001, 2002, 2003, 2004, 2005,
>>     2006, 2007, 2008, 2009, 2010, 2011, 2012
>>     The NetBSD Foundation, Inc.  All rights reserved.
>> Copyright (c) 1982, 1986, 1989, 1991, 1993
>>     The Regents of the University of California.  All rights reserved.
>>
>> NetBSD 6.1.3 (INSTALL)
>> Model: Qemu
>> total memory = 128 MB
>> avail memory = 119 MB
>> mainbus0 (root)
>> cpu0 at mainbus0: 604 (Revision 1.3), ID 0 (primary)
>> cpu0: HID0 0xc084<ICE,DCE,SGE,BHT>, powersave: 1
>> cpu0: 0.00 MHz
>> Couldn't find PNP data for bus 0 devfunc 0x0
>> pnpbus0 at mainbus0
>> pci0 at mainbus0 bus 0: indirect configuration space access
>> pchb0 at pci0 dev 0 function 0
>> pchb0: vendor 0x1057 product 0x4801 (rev. 0x00)
>> siop0 at pci0 dev 1 function 0: Symbios Logic 53c810 (fast scsi)
>> siop0: couldn't map interrupt
>> vga0 at pci0 dev 2 function 0: vendor 0x1234 product 0x1111 (rev. 0x02)
>> wsdisplay0 at vga0 (kbdmux ignored)
>> drm at vga0 not configured
>> pcn0 at pci0 dev 3 function 0: AMD PCnet-PCI Ethernet
>> pcn0: Am79c970A PCnet-PCI II rev 0, Ethernet address 52:54:00:12:34:56
>> pcn0: unable to map interrupt
>> pcib0 at pci0 dev 11 function 0: vendor 0x8086 product 0x0484 (rev. 0x03)
>> isa0 at pcib0
>> com0 at isa0 port 0x3f8-0x3ff irq 4: ns16550a, working fifo
>> com0: console
>> com1 at isa0 port 0x2f8-0x2ff irq 3: ns16550a, working fifo
>> pckbc0 at isa0 port 0x60-0x64
>> pckbd0 at pckbc0 (kbd slot)
>> pckbc0: using irq 1 for kbd slot
>> wskbd0 at pckbd0 (mux ignored)
>> vmmask 10000000 schedmask 10000000 highmask 70000000
>> boot device: mainbus0
>> root on md0a dumps on md0b
>> root file system type: ffs
>> WARNING: no TOD clock present
>> WARNING: using filesystem time
>> WARNING: CHECK AND RESET THE DATE!
>> erase ^H, werase ^W, kill ^U, intr ^C, status ^T
>> Terminal type? [vt100]
>>
>> ====================================================
>> 40p/official firmware with cdrom boot:
>>
>> Copyright (c) 1996, 1997, 1998, 1999, 2000, 2001, 2002, 2003, 2004, 2005,
>>     2006, 2007, 2008, 2009, 2010, 2011, 2012
>>     The NetBSD Foundation, Inc.  All rights reserved.
>> Copyright (c) 1982, 1986, 1989, 1991, 1993
>>     The Regents of the University of California.  All rights reserved.
>>
>> NetBSD 6.1.3 (INSTALL)
>> Model: IBM PPS Model 6015
>> total memory = 128 MB
>> avail memory = 119 MB
>> trap: kernel read DSI trap @ 0x481b4cae by 0x2a4f50 (DSISR 0x40000000,
>> err=14), lr 0x140e84
>> panic: trap
>>
>> The operating system has halted.
>> Please press any key to reboot.
>> ====================================================
>>
>> OpenBIOS doesn't support PReP boot partitions (type 0x41) nor PReP
>> kernels so this is a no-go yet.
> 
> Just out of interest, is it just the PReP boot partition support that is
> missing from OpenBIOS? If so, that should be fairly easy to implement if
> there's a spec lying around somewhere.

Not much magic required here - look for a partition with ID 0x41 and if
it's there, load its contents and treat it as an ELF file.

It's at least mentioned in the LoPAPR spec, see chapter B.11.1
("disk-label" support package).

 Thomas