Re: [Qemu-devel] PowerPC 440 support

Re: [Qemu-devel] PowerPC 440 support

[Hollis Blanchard]

Yes, I wrote the code you quoted.

In case there is any confusion, let me restate: You can boot a Bamboo
(PowerPC 440) guest under KVM on a PowerPC 440 host. KVM bypasses
qemu's CPU emulation (TCG), but uses qemu's device emulation.
Therefore, if someone were to implement 440 core emulation in qemu,
you could boot a 440 kernel with qemu without KVM.

Most devices found on 440 SoCs are the same as or very similar to the
devices found on 405 SoCs. Qemu's 440 device emulation isn't perfect,
but because Linux is highly modular, with a modified device tree you
can boot it. See pc-bios/bamboo.dts.

-Hollis

On Sat, Jun 13, 2009 at 10:47 PM, Baojun Wang <wangbj@gmail.com> wrote:
>
> in hw/ppc440.c:
>
>    env = cpu_ppc_init("440EP");
>    if (!env && kvm_enabled()) {
>        /* XXX Since qemu doesn't yet emulate 440, we just say it's a 405.
>         * Since KVM doesn't use qemu's CPU emulation it seems to be working
>         * OK. */
>        env = cpu_ppc_init("405");
>    }
>    if (!env) {
>        fprintf(stderr, "Unable to initialize CPU!\n");
>        exit(1);
>    }
>
> also in hw/ppc.c:
>
> I can find ppc40x_irq_init/e500_irq_init(used mpc8544ds), but there is
> no ppcbooke_irq_init? It seems hw/ppc405_uc.c is emulation for DCRs,
> PLB, DMA, GPIO, I2C.., but there is no hw/ppc44x_uc.c.
>
> the qemu source I used is 0.10.5.
>
> Also in ppc/translate_init.c, there lots of CONFIG_USER_ONLY, but I
> many of them are DEBUG or CACHE related SPR emulation, and since qemu
> doesn't emulate cache, I think it's OK.
>
>  Thanks,
> Wang
>
> On Sun, Jun 14, 2009 at 1:47 AM, Hollis Blanchard<hollis@penguinppc.org> wrote:
> > On Fri, Jun 12, 2009 at 10:48 AM, Blue Swirl <blauwirbel@gmail.com> wrote:
> >>
> >> On 6/11/09, Baojun Wang <wangbj@gmail.com> wrote:
> >> > could qemu emulate some board like bamboo (without kvm) or MPC8544ds
> >> > now? Thanks
> >>
> >> Yes, if someone adds emulation for these devices: UIC, PLB, DMA, POB,
> >> EBC, IIC, ZMII. Maybe some are not needed in all cases.
> >
> > No, qemu still doesn't emulate Book E cores, such as the PowerPC 440 in a
> > Bamboo board.
> >
> > UIC is of course emulated, otherwise KVM guests on 440 wouldn't get very
> > far. :) Enough 440 SoC devices are emulated to support Linux boot with a
> > properly stripped device tree.
> >
> > -Hollis
> >

Re: [Qemu-devel] PowerPC 440 support

[Blue Swirl]

[-- Attachment #1: Type: text/plain, Size: 3275 bytes --]

Sorry, I was very confused (I didn't look at ppc440.c).

For some reason, CPU model can't be specified on the command line. The
patch allows this, does it look OK?

Is there a kernel and initrd somewhere, so I could test this?

Currently I get (no kernel or ROM, so nothing to execute):
Truncating memory to 128 MiB to fit SDRAM controller limits.
ppc405_serial_init: offset 0000000000000300
QEMU 0.10.50 monitor - type 'help' for more information
(qemu) qemu: fatal: Trying to execute code outside RAM or ROM at
0x00000000fffffffc

NIP 00000000fffffffc   LR 0000000000000000 CTR 0000000000000000 XER 00000000
MSR 0000000000000000 HID0 0000000000000300  HF 0000000000000000 idx 1
Segmentation fault

On 6/14/09, Hollis Blanchard <hollis@penguinppc.org> wrote:
> Yes, I wrote the code you quoted.
>
>  In case there is any confusion, let me restate: You can boot a Bamboo
>  (PowerPC 440) guest under KVM on a PowerPC 440 host. KVM bypasses
>  qemu's CPU emulation (TCG), but uses qemu's device emulation.
>  Therefore, if someone were to implement 440 core emulation in qemu,
>  you could boot a 440 kernel with qemu without KVM.
>
>  Most devices found on 440 SoCs are the same as or very similar to the
>  devices found on 405 SoCs. Qemu's 440 device emulation isn't perfect,
>  but because Linux is highly modular, with a modified device tree you
>  can boot it. See pc-bios/bamboo.dts.
>
>  -Hollis
>
>  On Sat, Jun 13, 2009 at 10:47 PM, Baojun Wang <wangbj@gmail.com> wrote:
>  >
>  > in hw/ppc440.c:
>  >
>  >    env = cpu_ppc_init("440EP");
>  >    if (!env && kvm_enabled()) {
>  >        /* XXX Since qemu doesn't yet emulate 440, we just say it's a 405.
>  >         * Since KVM doesn't use qemu's CPU emulation it seems to be working
>  >         * OK. */
>  >        env = cpu_ppc_init("405");
>  >    }
>  >    if (!env) {
>  >        fprintf(stderr, "Unable to initialize CPU!\n");
>  >        exit(1);
>  >    }
>  >
>  > also in hw/ppc.c:
>  >
>  > I can find ppc40x_irq_init/e500_irq_init(used mpc8544ds), but there is
>  > no ppcbooke_irq_init? It seems hw/ppc405_uc.c is emulation for DCRs,
>  > PLB, DMA, GPIO, I2C.., but there is no hw/ppc44x_uc.c.
>  >
>  > the qemu source I used is 0.10.5.
>  >
>  > Also in ppc/translate_init.c, there lots of CONFIG_USER_ONLY, but I
>  > many of them are DEBUG or CACHE related SPR emulation, and since qemu
>  > doesn't emulate cache, I think it's OK.
>  >
>  >  Thanks,
>  > Wang
>  >
>  > On Sun, Jun 14, 2009 at 1:47 AM, Hollis Blanchard<hollis@penguinppc.org> wrote:
>  > > On Fri, Jun 12, 2009 at 10:48 AM, Blue Swirl <blauwirbel@gmail.com> wrote:
>  > >>
>  > >> On 6/11/09, Baojun Wang <wangbj@gmail.com> wrote:
>  > >> > could qemu emulate some board like bamboo (without kvm) or MPC8544ds
>  > >> > now? Thanks
>  > >>
>  > >> Yes, if someone adds emulation for these devices: UIC, PLB, DMA, POB,
>  > >> EBC, IIC, ZMII. Maybe some are not needed in all cases.
>  > >
>  > > No, qemu still doesn't emulate Book E cores, such as the PowerPC 440 in a
>  > > Bamboo board.
>  > >
>  > > UIC is of course emulated, otherwise KVM guests on 440 wouldn't get very
>  > > far. :) Enough 440 SoC devices are emulated to support Linux boot with a
>  > > properly stripped device tree.
>  > >
>  > > -Hollis
>  > >
>

[-- Attachment #2: 0001-Allow-user-to-specify-CPU-model.patch --]
[-- Type: application/x-patch, Size: 2427 bytes --]

Re: [Qemu-devel] PowerPC 440 support

[Hollis Blanchard]

My 440 board is inaccessible for a couple weeks, so I can't test your
patch. That said, the code looks fine.

However, I wonder what your goal is? You want to be able to create a
Bamboo board with e.g. a 750 processor? I don't think that would help
the original poster, and I'm not sure how useful it is, but I don't
object...

Either way I guess it will become a non-issue once PowerPC boards are
converted to the device tree infrastructure.

-Hollis

On Sun, Jun 14, 2009 at 1:33 PM, Blue Swirl<blauwirbel@gmail.com> wrote:
> Sorry, I was very confused (I didn't look at ppc440.c).
>
> For some reason, CPU model can't be specified on the command line. The
> patch allows this, does it look OK?
>
> Is there a kernel and initrd somewhere, so I could test this?
>
> Currently I get (no kernel or ROM, so nothing to execute):
> Truncating memory to 128 MiB to fit SDRAM controller limits.
> ppc405_serial_init: offset 0000000000000300
> QEMU 0.10.50 monitor - type 'help' for more information
> (qemu) qemu: fatal: Trying to execute code outside RAM or ROM at
> 0x00000000fffffffc
>
> NIP 00000000fffffffc   LR 0000000000000000 CTR 0000000000000000 XER 00000000
> MSR 0000000000000000 HID0 0000000000000300  HF 0000000000000000 idx 1
> Segmentation fault
>
> On 6/14/09, Hollis Blanchard <hollis@penguinppc.org> wrote:
>> Yes, I wrote the code you quoted.
>>
>>  In case there is any confusion, let me restate: You can boot a Bamboo
>>  (PowerPC 440) guest under KVM on a PowerPC 440 host. KVM bypasses
>>  qemu's CPU emulation (TCG), but uses qemu's device emulation.
>>  Therefore, if someone were to implement 440 core emulation in qemu,
>>  you could boot a 440 kernel with qemu without KVM.
>>
>>  Most devices found on 440 SoCs are the same as or very similar to the
>>  devices found on 405 SoCs. Qemu's 440 device emulation isn't perfect,
>>  but because Linux is highly modular, with a modified device tree you
>>  can boot it. See pc-bios/bamboo.dts.
>>
>>  -Hollis
>>
>>  On Sat, Jun 13, 2009 at 10:47 PM, Baojun Wang <wangbj@gmail.com> wrote:
>>  >
>>  > in hw/ppc440.c:
>>  >
>>  >    env = cpu_ppc_init("440EP");
>>  >    if (!env && kvm_enabled()) {
>>  >        /* XXX Since qemu doesn't yet emulate 440, we just say it's a 405.
>>  >         * Since KVM doesn't use qemu's CPU emulation it seems to be working
>>  >         * OK. */
>>  >        env = cpu_ppc_init("405");
>>  >    }
>>  >    if (!env) {
>>  >        fprintf(stderr, "Unable to initialize CPU!\n");
>>  >        exit(1);
>>  >    }
>>  >
>>  > also in hw/ppc.c:
>>  >
>>  > I can find ppc40x_irq_init/e500_irq_init(used mpc8544ds), but there is
>>  > no ppcbooke_irq_init? It seems hw/ppc405_uc.c is emulation for DCRs,
>>  > PLB, DMA, GPIO, I2C.., but there is no hw/ppc44x_uc.c.
>>  >
>>  > the qemu source I used is 0.10.5.
>>  >
>>  > Also in ppc/translate_init.c, there lots of CONFIG_USER_ONLY, but I
>>  > many of them are DEBUG or CACHE related SPR emulation, and since qemu
>>  > doesn't emulate cache, I think it's OK.
>>  >
>>  >  Thanks,
>>  > Wang
>>  >
>>  > On Sun, Jun 14, 2009 at 1:47 AM, Hollis Blanchard<hollis@penguinppc.org> wrote:
>>  > > On Fri, Jun 12, 2009 at 10:48 AM, Blue Swirl <blauwirbel@gmail.com> wrote:
>>  > >>
>>  > >> On 6/11/09, Baojun Wang <wangbj@gmail.com> wrote:
>>  > >> > could qemu emulate some board like bamboo (without kvm) or MPC8544ds
>>  > >> > now? Thanks
>>  > >>
>>  > >> Yes, if someone adds emulation for these devices: UIC, PLB, DMA, POB,
>>  > >> EBC, IIC, ZMII. Maybe some are not needed in all cases.
>>  > >
>>  > > No, qemu still doesn't emulate Book E cores, such as the PowerPC 440 in a
>>  > > Bamboo board.
>>  > >
>>  > > UIC is of course emulated, otherwise KVM guests on 440 wouldn't get very
>>  > > far. :) Enough 440 SoC devices are emulated to support Linux boot with a
>>  > > properly stripped device tree.
>>  > >
>>  > > -Hollis
>>  > >
>>
>

Re: [Qemu-devel] PowerPC 440 support

[Blue Swirl]

On 6/14/09, Hollis Blanchard <hollis@penguinppc.org> wrote:
> My 440 board is inaccessible for a couple weeks, so I can't test your
>  patch. That said, the code looks fine.
>
>  However, I wonder what your goal is? You want to be able to create a
>  Bamboo board with e.g. a 750 processor? I don't think that would help
>  the original poster, and I'm not sure how useful it is, but I don't
>  object...

That could be useful, but I'm trying to fix the CPU model selection
logic. It does not yield a working CPU without KVM.

>  Either way I guess it will become a non-issue once PowerPC boards are
>  converted to the device tree infrastructure.

Probably.

>
>
>  -Hollis
>
>
>  On Sun, Jun 14, 2009 at 1:33 PM, Blue Swirl<blauwirbel@gmail.com> wrote:
>  > Sorry, I was very confused (I didn't look at ppc440.c).
>  >
>  > For some reason, CPU model can't be specified on the command line. The
>  > patch allows this, does it look OK?
>  >
>  > Is there a kernel and initrd somewhere, so I could test this?
>  >
>  > Currently I get (no kernel or ROM, so nothing to execute):
>  > Truncating memory to 128 MiB to fit SDRAM controller limits.
>  > ppc405_serial_init: offset 0000000000000300
>  > QEMU 0.10.50 monitor - type 'help' for more information
>  > (qemu) qemu: fatal: Trying to execute code outside RAM or ROM at
>  > 0x00000000fffffffc
>  >
>  > NIP 00000000fffffffc   LR 0000000000000000 CTR 0000000000000000 XER 00000000
>  > MSR 0000000000000000 HID0 0000000000000300  HF 0000000000000000 idx 1
>  > Segmentation fault
>  >
>  > On 6/14/09, Hollis Blanchard <hollis@penguinppc.org> wrote:
>  >> Yes, I wrote the code you quoted.
>  >>
>  >>  In case there is any confusion, let me restate: You can boot a Bamboo
>  >>  (PowerPC 440) guest under KVM on a PowerPC 440 host. KVM bypasses
>  >>  qemu's CPU emulation (TCG), but uses qemu's device emulation.
>  >>  Therefore, if someone were to implement 440 core emulation in qemu,
>  >>  you could boot a 440 kernel with qemu without KVM.
>  >>
>  >>  Most devices found on 440 SoCs are the same as or very similar to the
>  >>  devices found on 405 SoCs. Qemu's 440 device emulation isn't perfect,
>  >>  but because Linux is highly modular, with a modified device tree you
>  >>  can boot it. See pc-bios/bamboo.dts.
>  >>
>  >>  -Hollis
>  >>
>  >>  On Sat, Jun 13, 2009 at 10:47 PM, Baojun Wang <wangbj@gmail.com> wrote:
>  >>  >
>  >>  > in hw/ppc440.c:
>  >>  >
>  >>  >    env = cpu_ppc_init("440EP");
>  >>  >    if (!env && kvm_enabled()) {
>  >>  >        /* XXX Since qemu doesn't yet emulate 440, we just say it's a 405.
>  >>  >         * Since KVM doesn't use qemu's CPU emulation it seems to be working
>  >>  >         * OK. */
>  >>  >        env = cpu_ppc_init("405");
>  >>  >    }
>  >>  >    if (!env) {
>  >>  >        fprintf(stderr, "Unable to initialize CPU!\n");
>  >>  >        exit(1);
>  >>  >    }
>  >>  >
>  >>  > also in hw/ppc.c:
>  >>  >
>  >>  > I can find ppc40x_irq_init/e500_irq_init(used mpc8544ds), but there is
>  >>  > no ppcbooke_irq_init? It seems hw/ppc405_uc.c is emulation for DCRs,
>  >>  > PLB, DMA, GPIO, I2C.., but there is no hw/ppc44x_uc.c.
>  >>  >
>  >>  > the qemu source I used is 0.10.5.
>  >>  >
>  >>  > Also in ppc/translate_init.c, there lots of CONFIG_USER_ONLY, but I
>  >>  > many of them are DEBUG or CACHE related SPR emulation, and since qemu
>  >>  > doesn't emulate cache, I think it's OK.
>  >>  >
>  >>  >  Thanks,
>  >>  > Wang
>  >>  >
>  >>  > On Sun, Jun 14, 2009 at 1:47 AM, Hollis Blanchard<hollis@penguinppc.org> wrote:
>  >>  > > On Fri, Jun 12, 2009 at 10:48 AM, Blue Swirl <blauwirbel@gmail.com> wrote:
>  >>  > >>
>  >>  > >> On 6/11/09, Baojun Wang <wangbj@gmail.com> wrote:
>  >>  > >> > could qemu emulate some board like bamboo (without kvm) or MPC8544ds
>  >>  > >> > now? Thanks
>  >>  > >>
>  >>  > >> Yes, if someone adds emulation for these devices: UIC, PLB, DMA, POB,
>  >>  > >> EBC, IIC, ZMII. Maybe some are not needed in all cases.
>  >>  > >
>  >>  > > No, qemu still doesn't emulate Book E cores, such as the PowerPC 440 in a
>  >>  > > Bamboo board.
>  >>  > >
>  >>  > > UIC is of course emulated, otherwise KVM guests on 440 wouldn't get very
>  >>  > > far. :) Enough 440 SoC devices are emulated to support Linux boot with a
>  >>  > > properly stripped device tree.
>  >>  > >
>  >>  > > -Hollis
>  >>  > >
>  >>
>  >
>

Re: [Qemu-devel] PowerPC 440 support

[Baojun Wang]

It seems most boards will converted to the device tree infrastructure?

but I think we will need a firmware first before loading the linux
kernel, I don't know if qemu-system-ppcemb could run kernel directly
without a firmware..

  Best Regards,
Wang

On Mon, Jun 15, 2009 at 3:46 AM, Hollis Blanchard<hollis@penguinppc.org> wrote:
> My 440 board is inaccessible for a couple weeks, so I can't test your
> patch. That said, the code looks fine.
>
> However, I wonder what your goal is? You want to be able to create a
> Bamboo board with e.g. a 750 processor? I don't think that would help
> the original poster, and I'm not sure how useful it is, but I don't
> object...
>
> Either way I guess it will become a non-issue once PowerPC boards are
> converted to the device tree infrastructure.
>
> -Hollis
>
> On Sun, Jun 14, 2009 at 1:33 PM, Blue Swirl<blauwirbel@gmail.com> wrote:
>> Sorry, I was very confused (I didn't look at ppc440.c).
>>
>> For some reason, CPU model can't be specified on the command line. The
>> patch allows this, does it look OK?
>>
>> Is there a kernel and initrd somewhere, so I could test this?
>>
>> Currently I get (no kernel or ROM, so nothing to execute):
>> Truncating memory to 128 MiB to fit SDRAM controller limits.
>> ppc405_serial_init: offset 0000000000000300
>> QEMU 0.10.50 monitor - type 'help' for more information
>> (qemu) qemu: fatal: Trying to execute code outside RAM or ROM at
>> 0x00000000fffffffc
>>
>> NIP 00000000fffffffc   LR 0000000000000000 CTR 0000000000000000 XER 00000000
>> MSR 0000000000000000 HID0 0000000000000300  HF 0000000000000000 idx 1
>> Segmentation fault
>>
>> On 6/14/09, Hollis Blanchard <hollis@penguinppc.org> wrote:
>>> Yes, I wrote the code you quoted.
>>>
>>>  In case there is any confusion, let me restate: You can boot a Bamboo
>>>  (PowerPC 440) guest under KVM on a PowerPC 440 host. KVM bypasses
>>>  qemu's CPU emulation (TCG), but uses qemu's device emulation.
>>>  Therefore, if someone were to implement 440 core emulation in qemu,
>>>  you could boot a 440 kernel with qemu without KVM.
>>>
>>>  Most devices found on 440 SoCs are the same as or very similar to the
>>>  devices found on 405 SoCs. Qemu's 440 device emulation isn't perfect,
>>>  but because Linux is highly modular, with a modified device tree you
>>>  can boot it. See pc-bios/bamboo.dts.
>>>
>>>  -Hollis
>>>
>>>  On Sat, Jun 13, 2009 at 10:47 PM, Baojun Wang <wangbj@gmail.com> wrote:
>>>  >
>>>  > in hw/ppc440.c:
>>>  >
>>>  >    env = cpu_ppc_init("440EP");
>>>  >    if (!env && kvm_enabled()) {
>>>  >        /* XXX Since qemu doesn't yet emulate 440, we just say it's a 405.
>>>  >         * Since KVM doesn't use qemu's CPU emulation it seems to be working
>>>  >         * OK. */
>>>  >        env = cpu_ppc_init("405");
>>>  >    }
>>>  >    if (!env) {
>>>  >        fprintf(stderr, "Unable to initialize CPU!\n");
>>>  >        exit(1);
>>>  >    }
>>>  >
>>>  > also in hw/ppc.c:
>>>  >
>>>  > I can find ppc40x_irq_init/e500_irq_init(used mpc8544ds), but there is
>>>  > no ppcbooke_irq_init? It seems hw/ppc405_uc.c is emulation for DCRs,
>>>  > PLB, DMA, GPIO, I2C.., but there is no hw/ppc44x_uc.c.
>>>  >
>>>  > the qemu source I used is 0.10.5.
>>>  >
>>>  > Also in ppc/translate_init.c, there lots of CONFIG_USER_ONLY, but I
>>>  > many of them are DEBUG or CACHE related SPR emulation, and since qemu
>>>  > doesn't emulate cache, I think it's OK.
>>>  >
>>>  >  Thanks,
>>>  > Wang
>>>  >
>>>  > On Sun, Jun 14, 2009 at 1:47 AM, Hollis Blanchard<hollis@penguinppc.org> wrote:
>>>  > > On Fri, Jun 12, 2009 at 10:48 AM, Blue Swirl <blauwirbel@gmail.com> wrote:
>>>  > >>
>>>  > >> On 6/11/09, Baojun Wang <wangbj@gmail.com> wrote:
>>>  > >> > could qemu emulate some board like bamboo (without kvm) or MPC8544ds
>>>  > >> > now? Thanks
>>>  > >>
>>>  > >> Yes, if someone adds emulation for these devices: UIC, PLB, DMA, POB,
>>>  > >> EBC, IIC, ZMII. Maybe some are not needed in all cases.
>>>  > >
>>>  > > No, qemu still doesn't emulate Book E cores, such as the PowerPC 440 in a
>>>  > > Bamboo board.
>>>  > >
>>>  > > UIC is of course emulated, otherwise KVM guests on 440 wouldn't get very
>>>  > > far. :) Enough 440 SoC devices are emulated to support Linux boot with a
>>>  > > properly stripped device tree.
>>>  > >
>>>  > > -Hollis
>>>  > >
>>>
>>
>

Re: [Qemu-devel] PowerPC 440 support

[Hollis Blanchard]

[-- Attachment #1: Type: text/plain, Size: 5387 bytes --]

KVM PPC execution doesn't use firmware today. Instead we create the device
tree in qemu itself, stuff it into guest memory, and point a guest register
at it on entry. This was just a shortcut/hack, because we didn't have enough
time to enable both Linux and uboot.

I agree that the best way to do things long-term is to run u-boot inside the
guest environment. That will likely require improvements to qemu's device
emulation, and also we'll probably need to work out a way for qemu to pass
parameters (e.g. memory size) to u-boot. IMHO, the best approach there would
be to have u-boot interpret a device tree from qemu, then modify it and pass
it on to the kernel. Obviously that will require u-boot work.

-Hollis

On Sun, Jun 14, 2009 at 11:40 PM, Baojun Wang <wangbj@gmail.com> wrote:

> It seems most boards will converted to the device tree infrastructure?
>
> but I think we will need a firmware first before loading the linux
> kernel, I don't know if qemu-system-ppcemb could run kernel directly
> without a firmware..
>
>  Best Regards,
> Wang
>
> On Mon, Jun 15, 2009 at 3:46 AM, Hollis Blanchard<hollis@penguinppc.org>
> wrote:
> > My 440 board is inaccessible for a couple weeks, so I can't test your
> > patch. That said, the code looks fine.
> >
> > However, I wonder what your goal is? You want to be able to create a
> > Bamboo board with e.g. a 750 processor? I don't think that would help
> > the original poster, and I'm not sure how useful it is, but I don't
> > object...
> >
> > Either way I guess it will become a non-issue once PowerPC boards are
> > converted to the device tree infrastructure.
> >
> > -Hollis
> >
> > On Sun, Jun 14, 2009 at 1:33 PM, Blue Swirl<blauwirbel@gmail.com> wrote:
> >> Sorry, I was very confused (I didn't look at ppc440.c).
> >>
> >> For some reason, CPU model can't be specified on the command line. The
> >> patch allows this, does it look OK?
> >>
> >> Is there a kernel and initrd somewhere, so I could test this?
> >>
> >> Currently I get (no kernel or ROM, so nothing to execute):
> >> Truncating memory to 128 MiB to fit SDRAM controller limits.
> >> ppc405_serial_init: offset 0000000000000300
> >> QEMU 0.10.50 monitor - type 'help' for more information
> >> (qemu) qemu: fatal: Trying to execute code outside RAM or ROM at
> >> 0x00000000fffffffc
> >>
> >> NIP 00000000fffffffc   LR 0000000000000000 CTR 0000000000000000 XER
> 00000000
> >> MSR 0000000000000000 HID0 0000000000000300  HF 0000000000000000 idx 1
> >> Segmentation fault
> >>
> >> On 6/14/09, Hollis Blanchard <hollis@penguinppc.org> wrote:
> >>> Yes, I wrote the code you quoted.
> >>>
> >>>  In case there is any confusion, let me restate: You can boot a Bamboo
> >>>  (PowerPC 440) guest under KVM on a PowerPC 440 host. KVM bypasses
> >>>  qemu's CPU emulation (TCG), but uses qemu's device emulation.
> >>>  Therefore, if someone were to implement 440 core emulation in qemu,
> >>>  you could boot a 440 kernel with qemu without KVM.
> >>>
> >>>  Most devices found on 440 SoCs are the same as or very similar to the
> >>>  devices found on 405 SoCs. Qemu's 440 device emulation isn't perfect,
> >>>  but because Linux is highly modular, with a modified device tree you
> >>>  can boot it. See pc-bios/bamboo.dts.
> >>>
> >>>  -Hollis
> >>>
> >>>  On Sat, Jun 13, 2009 at 10:47 PM, Baojun Wang <wangbj@gmail.com>
> wrote:
> >>>  >
> >>>  > in hw/ppc440.c:
> >>>  >
> >>>  >    env = cpu_ppc_init("440EP");
> >>>  >    if (!env && kvm_enabled()) {
> >>>  >        /* XXX Since qemu doesn't yet emulate 440, we just say it's a
> 405.
> >>>  >         * Since KVM doesn't use qemu's CPU emulation it seems to be
> working
> >>>  >         * OK. */
> >>>  >        env = cpu_ppc_init("405");
> >>>  >    }
> >>>  >    if (!env) {
> >>>  >        fprintf(stderr, "Unable to initialize CPU!\n");
> >>>  >        exit(1);
> >>>  >    }
> >>>  >
> >>>  > also in hw/ppc.c:
> >>>  >
> >>>  > I can find ppc40x_irq_init/e500_irq_init(used mpc8544ds), but there
> is
> >>>  > no ppcbooke_irq_init? It seems hw/ppc405_uc.c is emulation for DCRs,
> >>>  > PLB, DMA, GPIO, I2C.., but there is no hw/ppc44x_uc.c.
> >>>  >
> >>>  > the qemu source I used is 0.10.5.
> >>>  >
> >>>  > Also in ppc/translate_init.c, there lots of CONFIG_USER_ONLY, but I
> >>>  > many of them are DEBUG or CACHE related SPR emulation, and since
> qemu
> >>>  > doesn't emulate cache, I think it's OK.
> >>>  >
> >>>  >  Thanks,
> >>>  > Wang
> >>>  >
> >>>  > On Sun, Jun 14, 2009 at 1:47 AM, Hollis Blanchard<
> hollis@penguinppc.org> wrote:
> >>>  > > On Fri, Jun 12, 2009 at 10:48 AM, Blue Swirl <
> blauwirbel@gmail.com> wrote:
> >>>  > >>
> >>>  > >> On 6/11/09, Baojun Wang <wangbj@gmail.com> wrote:
> >>>  > >> > could qemu emulate some board like bamboo (without kvm) or
> MPC8544ds
> >>>  > >> > now? Thanks
> >>>  > >>
> >>>  > >> Yes, if someone adds emulation for these devices: UIC, PLB, DMA,
> POB,
> >>>  > >> EBC, IIC, ZMII. Maybe some are not needed in all cases.
> >>>  > >
> >>>  > > No, qemu still doesn't emulate Book E cores, such as the PowerPC
> 440 in a
> >>>  > > Bamboo board.
> >>>  > >
> >>>  > > UIC is of course emulated, otherwise KVM guests on 440 wouldn't
> get very
> >>>  > > far. :) Enough 440 SoC devices are emulated to support Linux boot
> with a
> >>>  > > properly stripped device tree.
> >>>  > >
> >>>  > > -Hollis
> >>>  > >
> >>>
> >>
> >
>

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Re: [Qemu-devel] PowerPC 440 support

[Blue Swirl]

On 6/15/09, Hollis Blanchard <hollis@penguinppc.org> wrote:
> KVM PPC execution doesn't use firmware today. Instead we create the device
> tree in qemu itself, stuff it into guest memory, and point a guest register
> at it on entry. This was just a shortcut/hack, because we didn't have enough
> time to enable both Linux and uboot.
>
> I agree that the best way to do things long-term is to run u-boot inside the
> guest environment. That will likely require improvements to qemu's device
> emulation, and also we'll probably need to work out a way for qemu to pass
> parameters (e.g. memory size) to u-boot. IMHO, the best approach there would
> be to have u-boot interpret a device tree from qemu, then modify it and pass
> it on to the kernel. Obviously that will require u-boot work.

I'm not familiar with u-boot, could we use OpenBIOS instead? Is u-boot
used on real hardware?

Re: [Qemu-devel] PowerPC 440 support

[Hollis Blanchard]

[-- Attachment #1: Type: text/plain, Size: 1127 bytes --]

On Mon, Jun 15, 2009 at 11:52 AM, Blue Swirl <blauwirbel@gmail.com> wrote:

> On 6/15/09, Hollis Blanchard <hollis@penguinppc.org> wrote:
> > KVM PPC execution doesn't use firmware today. Instead we create the
> device
> > tree in qemu itself, stuff it into guest memory, and point a guest
> register
> > at it on entry. This was just a shortcut/hack, because we didn't have
> enough
> > time to enable both Linux and uboot.
> >
> > I agree that the best way to do things long-term is to run u-boot inside
> the
> > guest environment. That will likely require improvements to qemu's device
> > emulation, and also we'll probably need to work out a way for qemu to
> pass
> > parameters (e.g. memory size) to u-boot. IMHO, the best approach there
> would
> > be to have u-boot interpret a device tree from qemu, then modify it and
> pass
> > it on to the kernel. Obviously that will require u-boot work.
>
> I'm not familiar with u-boot, could we use OpenBIOS instead? Is u-boot
> used on real hardware?
>

Yes, u-boot is used on a wide variety of real hardware. Open Firmware is
almost unheard-of in embedded systems.

-Hollis

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Re: [Qemu-devel] PowerPC 440 support

[Baojun Wang]

I think the idea is very good, otherwise it will take too much time to
finish, and it gives us a way to lauch kernel directly without a
firmware.

I have some question about the new qemu device tree, in ppc440_bamboo.c:

function bamboo_load_device_tree() is only usable when HAVE_FDT
defined as 1, but currently (even with git version) version (0.10.5)
we can not enable this feature? I have forced HAVE_FDT to be defined
by:

echo '#define HAVE_FDT 1' >> config-host.h

&

echo 'FDT_LIBS=-lfdt' >> config-host.mak

but that lead to compile error, seems device tree in qemu is not fully
populated?

  Regard & Thanks,
Wang

On Mon, Jun 15, 2009 at 11:46 PM, Hollis Blanchard<hollis@penguinppc.org> wrote:
> KVM PPC execution doesn't use firmware today. Instead we create the device
> tree in qemu itself, stuff it into guest memory, and point a guest register
> at it on entry. This was just a shortcut/hack, because we didn't have enough
> time to enable both Linux and uboot.
>
> I agree that the best way to do things long-term is to run u-boot inside the
> guest environment. That will likely require improvements to qemu's device
> emulation, and also we'll probably need to work out a way for qemu to pass
> parameters (e.g. memory size) to u-boot. IMHO, the best approach there would
> be to have u-boot interpret a device tree from qemu, then modify it and pass
> it on to the kernel. Obviously that will require u-boot work.
>
> -Hollis
>
> On Sun, Jun 14, 2009 at 11:40 PM, Baojun Wang <wangbj@gmail.com> wrote:
>>
>> It seems most boards will converted to the device tree infrastructure?
>>
>> but I think we will need a firmware first before loading the linux
>> kernel, I don't know if qemu-system-ppcemb could run kernel directly
>> without a firmware..
>>
>>  Best Regards,
>> Wang
>>
>> On Mon, Jun 15, 2009 at 3:46 AM, Hollis Blanchard<hollis@penguinppc.org>
>> wrote:
>> > My 440 board is inaccessible for a couple weeks, so I can't test your
>> > patch. That said, the code looks fine.
>> >
>> > However, I wonder what your goal is? You want to be able to create a
>> > Bamboo board with e.g. a 750 processor? I don't think that would help
>> > the original poster, and I'm not sure how useful it is, but I don't
>> > object...
>> >
>> > Either way I guess it will become a non-issue once PowerPC boards are
>> > converted to the device tree infrastructure.
>> >
>> > -Hollis
>> >
>> > On Sun, Jun 14, 2009 at 1:33 PM, Blue Swirl<blauwirbel@gmail.com> wrote:
>> >> Sorry, I was very confused (I didn't look at ppc440.c).
>> >>
>> >> For some reason, CPU model can't be specified on the command line. The
>> >> patch allows this, does it look OK?
>> >>
>> >> Is there a kernel and initrd somewhere, so I could test this?
>> >>
>> >> Currently I get (no kernel or ROM, so nothing to execute):
>> >> Truncating memory to 128 MiB to fit SDRAM controller limits.
>> >> ppc405_serial_init: offset 0000000000000300
>> >> QEMU 0.10.50 monitor - type 'help' for more information
>> >> (qemu) qemu: fatal: Trying to execute code outside RAM or ROM at
>> >> 0x00000000fffffffc
>> >>
>> >> NIP 00000000fffffffc   LR 0000000000000000 CTR 0000000000000000 XER
>> >> 00000000
>> >> MSR 0000000000000000 HID0 0000000000000300  HF 0000000000000000 idx 1
>> >> Segmentation fault
>> >>
>> >> On 6/14/09, Hollis Blanchard <hollis@penguinppc.org> wrote:
>> >>> Yes, I wrote the code you quoted.
>> >>>
>> >>>  In case there is any confusion, let me restate: You can boot a Bamboo
>> >>>  (PowerPC 440) guest under KVM on a PowerPC 440 host. KVM bypasses
>> >>>  qemu's CPU emulation (TCG), but uses qemu's device emulation.
>> >>>  Therefore, if someone were to implement 440 core emulation in qemu,
>> >>>  you could boot a 440 kernel with qemu without KVM.
>> >>>
>> >>>  Most devices found on 440 SoCs are the same as or very similar to the
>> >>>  devices found on 405 SoCs. Qemu's 440 device emulation isn't perfect,
>> >>>  but because Linux is highly modular, with a modified device tree you
>> >>>  can boot it. See pc-bios/bamboo.dts.
>> >>>
>> >>>  -Hollis
>> >>>
>> >>>  On Sat, Jun 13, 2009 at 10:47 PM, Baojun Wang <wangbj@gmail.com>
>> >>> wrote:
>> >>>  >
>> >>>  > in hw/ppc440.c:
>> >>>  >
>> >>>  >    env = cpu_ppc_init("440EP");
>> >>>  >    if (!env && kvm_enabled()) {
>> >>>  >        /* XXX Since qemu doesn't yet emulate 440, we just say it's
>> >>> a 405.
>> >>>  >         * Since KVM doesn't use qemu's CPU emulation it seems to be
>> >>> working
>> >>>  >         * OK. */
>> >>>  >        env = cpu_ppc_init("405");
>> >>>  >    }
>> >>>  >    if (!env) {
>> >>>  >        fprintf(stderr, "Unable to initialize CPU!\n");
>> >>>  >        exit(1);
>> >>>  >    }
>> >>>  >
>> >>>  > also in hw/ppc.c:
>> >>>  >
>> >>>  > I can find ppc40x_irq_init/e500_irq_init(used mpc8544ds), but there
>> >>> is
>> >>>  > no ppcbooke_irq_init? It seems hw/ppc405_uc.c is emulation for
>> >>> DCRs,
>> >>>  > PLB, DMA, GPIO, I2C.., but there is no hw/ppc44x_uc.c.
>> >>>  >
>> >>>  > the qemu source I used is 0.10.5.
>> >>>  >
>> >>>  > Also in ppc/translate_init.c, there lots of CONFIG_USER_ONLY, but I
>> >>>  > many of them are DEBUG or CACHE related SPR emulation, and since
>> >>> qemu
>> >>>  > doesn't emulate cache, I think it's OK.
>> >>>  >
>> >>>  >  Thanks,
>> >>>  > Wang
>> >>>  >
>> >>>  > On Sun, Jun 14, 2009 at 1:47 AM, Hollis
>> >>> Blanchard<hollis@penguinppc.org> wrote:
>> >>>  > > On Fri, Jun 12, 2009 at 10:48 AM, Blue Swirl
>> >>> <blauwirbel@gmail.com> wrote:
>> >>>  > >>
>> >>>  > >> On 6/11/09, Baojun Wang <wangbj@gmail.com> wrote:
>> >>>  > >> > could qemu emulate some board like bamboo (without kvm) or
>> >>> MPC8544ds
>> >>>  > >> > now? Thanks
>> >>>  > >>
>> >>>  > >> Yes, if someone adds emulation for these devices: UIC, PLB, DMA,
>> >>> POB,
>> >>>  > >> EBC, IIC, ZMII. Maybe some are not needed in all cases.
>> >>>  > >
>> >>>  > > No, qemu still doesn't emulate Book E cores, such as the PowerPC
>> >>> 440 in a
>> >>>  > > Bamboo board.
>> >>>  > >
>> >>>  > > UIC is of course emulated, otherwise KVM guests on 440 wouldn't
>> >>> get very
>> >>>  > > far. :) Enough 440 SoC devices are emulated to support Linux boot
>> >>> with a
>> >>>  > > properly stripped device tree.
>> >>>  > >
>> >>>  > > -Hollis
>> >>>  > >
>> >>>
>> >>
>> >
>
>

Re: [Qemu-devel] PowerPC 440 support

[Hollis Blanchard]

On Tue, Jun 16, 2009 at 10:12 AM, Baojun Wang<wangbj@gmail.com> wrote:
> I think the idea is very good, otherwise it will take too much time to
> finish, and it gives us a way to lauch kernel directly without a
> firmware.

Note however that this approach means qemu must initialize the target
as if u-boot had. Practically speaking, that means device tree,
initial register values, and also TLB entries. At least on some
platforms, u-boot leaves a UART mapping for early kernel use.

> I have some question about the new qemu device tree, in ppc440_bamboo.c:
>
> function bamboo_load_device_tree() is only usable when HAVE_FDT
> defined as 1, but currently (even with git version) version (0.10.5)
> we can not enable this feature? I have forced HAVE_FDT to be defined
> by:
>
> echo '#define HAVE_FDT 1' >> config-host.h
>
> &
>
> echo 'FDT_LIBS=-lfdt' >> config-host.mak
>
> but that lead to compile error, seems device tree in qemu is not fully
> populated?

Do you have libfdt installed? If so, configure should have found it,
and you wouldn't need to mess with config-host.* manually.

Currently there are no distribution packages for libfdt. You must
download dtc source (http://git.jdl.com/gitweb/?p=dtc.git;a=summary)
and install libfdt by hand from there.

-Hollis

>  Regard & Thanks,
> Wang
>
> On Mon, Jun 15, 2009 at 11:46 PM, Hollis Blanchard<hollis@penguinppc.org> wrote:
>> KVM PPC execution doesn't use firmware today. Instead we create the device
>> tree in qemu itself, stuff it into guest memory, and point a guest register
>> at it on entry. This was just a shortcut/hack, because we didn't have enough
>> time to enable both Linux and uboot.
>>
>> I agree that the best way to do things long-term is to run u-boot inside the
>> guest environment. That will likely require improvements to qemu's device
>> emulation, and also we'll probably need to work out a way for qemu to pass
>> parameters (e.g. memory size) to u-boot. IMHO, the best approach there would
>> be to have u-boot interpret a device tree from qemu, then modify it and pass
>> it on to the kernel. Obviously that will require u-boot work.
>>
>> -Hollis
>>
>> On Sun, Jun 14, 2009 at 11:40 PM, Baojun Wang <wangbj@gmail.com> wrote:
>>>
>>> It seems most boards will converted to the device tree infrastructure?
>>>
>>> but I think we will need a firmware first before loading the linux
>>> kernel, I don't know if qemu-system-ppcemb could run kernel directly
>>> without a firmware..
>>>
>>>  Best Regards,
>>> Wang
>>>
>>> On Mon, Jun 15, 2009 at 3:46 AM, Hollis Blanchard<hollis@penguinppc.org>
>>> wrote:
>>> > My 440 board is inaccessible for a couple weeks, so I can't test your
>>> > patch. That said, the code looks fine.
>>> >
>>> > However, I wonder what your goal is? You want to be able to create a
>>> > Bamboo board with e.g. a 750 processor? I don't think that would help
>>> > the original poster, and I'm not sure how useful it is, but I don't
>>> > object...
>>> >
>>> > Either way I guess it will become a non-issue once PowerPC boards are
>>> > converted to the device tree infrastructure.
>>> >
>>> > -Hollis
>>> >
>>> > On Sun, Jun 14, 2009 at 1:33 PM, Blue Swirl<blauwirbel@gmail.com> wrote:
>>> >> Sorry, I was very confused (I didn't look at ppc440.c).
>>> >>
>>> >> For some reason, CPU model can't be specified on the command line. The
>>> >> patch allows this, does it look OK?
>>> >>
>>> >> Is there a kernel and initrd somewhere, so I could test this?
>>> >>
>>> >> Currently I get (no kernel or ROM, so nothing to execute):
>>> >> Truncating memory to 128 MiB to fit SDRAM controller limits.
>>> >> ppc405_serial_init: offset 0000000000000300
>>> >> QEMU 0.10.50 monitor - type 'help' for more information
>>> >> (qemu) qemu: fatal: Trying to execute code outside RAM or ROM at
>>> >> 0x00000000fffffffc
>>> >>
>>> >> NIP 00000000fffffffc   LR 0000000000000000 CTR 0000000000000000 XER
>>> >> 00000000
>>> >> MSR 0000000000000000 HID0 0000000000000300  HF 0000000000000000 idx 1
>>> >> Segmentation fault
>>> >>
>>> >> On 6/14/09, Hollis Blanchard <hollis@penguinppc.org> wrote:
>>> >>> Yes, I wrote the code you quoted.
>>> >>>
>>> >>>  In case there is any confusion, let me restate: You can boot a Bamboo
>>> >>>  (PowerPC 440) guest under KVM on a PowerPC 440 host. KVM bypasses
>>> >>>  qemu's CPU emulation (TCG), but uses qemu's device emulation.
>>> >>>  Therefore, if someone were to implement 440 core emulation in qemu,
>>> >>>  you could boot a 440 kernel with qemu without KVM.
>>> >>>
>>> >>>  Most devices found on 440 SoCs are the same as or very similar to the
>>> >>>  devices found on 405 SoCs. Qemu's 440 device emulation isn't perfect,
>>> >>>  but because Linux is highly modular, with a modified device tree you
>>> >>>  can boot it. See pc-bios/bamboo.dts.
>>> >>>
>>> >>>  -Hollis
>>> >>>
>>> >>>  On Sat, Jun 13, 2009 at 10:47 PM, Baojun Wang <wangbj@gmail.com>
>>> >>> wrote:
>>> >>>  >
>>> >>>  > in hw/ppc440.c:
>>> >>>  >
>>> >>>  >    env = cpu_ppc_init("440EP");
>>> >>>  >    if (!env && kvm_enabled()) {
>>> >>>  >        /* XXX Since qemu doesn't yet emulate 440, we just say it's
>>> >>> a 405.
>>> >>>  >         * Since KVM doesn't use qemu's CPU emulation it seems to be
>>> >>> working
>>> >>>  >         * OK. */
>>> >>>  >        env = cpu_ppc_init("405");
>>> >>>  >    }
>>> >>>  >    if (!env) {
>>> >>>  >        fprintf(stderr, "Unable to initialize CPU!\n");
>>> >>>  >        exit(1);
>>> >>>  >    }
>>> >>>  >
>>> >>>  > also in hw/ppc.c:
>>> >>>  >
>>> >>>  > I can find ppc40x_irq_init/e500_irq_init(used mpc8544ds), but there
>>> >>> is
>>> >>>  > no ppcbooke_irq_init? It seems hw/ppc405_uc.c is emulation for
>>> >>> DCRs,
>>> >>>  > PLB, DMA, GPIO, I2C.., but there is no hw/ppc44x_uc.c.
>>> >>>  >
>>> >>>  > the qemu source I used is 0.10.5.
>>> >>>  >
>>> >>>  > Also in ppc/translate_init.c, there lots of CONFIG_USER_ONLY, but I
>>> >>>  > many of them are DEBUG or CACHE related SPR emulation, and since
>>> >>> qemu
>>> >>>  > doesn't emulate cache, I think it's OK.
>>> >>>  >
>>> >>>  >  Thanks,
>>> >>>  > Wang
>>> >>>  >
>>> >>>  > On Sun, Jun 14, 2009 at 1:47 AM, Hollis
>>> >>> Blanchard<hollis@penguinppc.org> wrote:
>>> >>>  > > On Fri, Jun 12, 2009 at 10:48 AM, Blue Swirl
>>> >>> <blauwirbel@gmail.com> wrote:
>>> >>>  > >>
>>> >>>  > >> On 6/11/09, Baojun Wang <wangbj@gmail.com> wrote:
>>> >>>  > >> > could qemu emulate some board like bamboo (without kvm) or
>>> >>> MPC8544ds
>>> >>>  > >> > now? Thanks
>>> >>>  > >>
>>> >>>  > >> Yes, if someone adds emulation for these devices: UIC, PLB, DMA,
>>> >>> POB,
>>> >>>  > >> EBC, IIC, ZMII. Maybe some are not needed in all cases.
>>> >>>  > >
>>> >>>  > > No, qemu still doesn't emulate Book E cores, such as the PowerPC
>>> >>> 440 in a
>>> >>>  > > Bamboo board.
>>> >>>  > >
>>> >>>  > > UIC is of course emulated, otherwise KVM guests on 440 wouldn't
>>> >>> get very
>>> >>>  > > far. :) Enough 440 SoC devices are emulated to support Linux boot
>>> >>> with a
>>> >>>  > > properly stripped device tree.
>>> >>>  > >
>>> >>>  > > -Hollis
>>> >>>  > >
>>> >>>
>>> >>
>>> >
>>
>>
>

Re: [Qemu-devel] PowerPC 440 support

[Baojun Wang]

I think we can use u-boot as the firmware for testing, but to compile
u-boot, we have to choose a board first..

for bamboo (440ep) or mpc8544ds, we could compile a u-boot like:

make ARCH=ppc bamboo_config
or
make ARCH=ppc MPC8544DS_config

then

make ARCH=ppc CROSS_COMPILE=powerpc-unknown-linux-gnu-

this will produce u-boot.bin, and we could use

qemu-system-ppcemb -m bamboo -kernel u-boot.bin -net nic -net tap

to verify if qemu-works.

during reset, the ppc processor start (ip) at address 0xFFFF_FFFC, so
I think we need a firmware be loaded at that address.
I have check ppc_oldworld.c, it tries to load the firmware first
openbios-ppc (should be of compatible) :

    snprintf(buf, sizeof(buf), "%s/%s", bios_dir, bios_name);
    cpu_register_physical_memory(PROM_ADDR, BIOS_SIZE, bios_offset |
IO_MEM_ROM);

    /* Load OpenBIOS (ELF) */
    bios_size = load_elf(buf, 0, NULL, NULL, NULL);

PROM_ADDR is at 0xFFF0_0000 and BIOS_SIZE is 1MB (last 1MB, mpc85xx
default ROM location is last 8MB from 0xFF80_0000, but boot loader
like u-boot only use the last 512KB), and the openbios-ppc should be a
crafted ELF file just like u-boot which have put some _magic_ at
0xFFFF_FFFC so that the CPU could go on during reset.

I have ever used qemu-system-arm to start the integratorcp board's
u-boot, and then use the u-boot to start a linux kernel (integratorcp)
successfully.

Few days ago I haved tried to uncomment the CONFIG_USER_ONLY macro in
ppc/translate_init.c, but qemu-system-ppcemb still failed, so I guess
the ppc booke softmmu still have some minor problem.

  Best Regards,
Wang

On Mon, Jun 15, 2009 at 2:33 AM, Blue Swirl<blauwirbel@gmail.com> wrote:
> Sorry, I was very confused (I didn't look at ppc440.c).
>
> For some reason, CPU model can't be specified on the command line. The
> patch allows this, does it look OK?
>
> Is there a kernel and initrd somewhere, so I could test this?
>
> Currently I get (no kernel or ROM, so nothing to execute):
> Truncating memory to 128 MiB to fit SDRAM controller limits.
> ppc405_serial_init: offset 0000000000000300
> QEMU 0.10.50 monitor - type 'help' for more information
> (qemu) qemu: fatal: Trying to execute code outside RAM or ROM at
> 0x00000000fffffffc
>
> NIP 00000000fffffffc   LR 0000000000000000 CTR 0000000000000000 XER 00000000
> MSR 0000000000000000 HID0 0000000000000300  HF 0000000000000000 idx 1
> Segmentation fault
>
> On 6/14/09, Hollis Blanchard <hollis@penguinppc.org> wrote:
>> Yes, I wrote the code you quoted.
>>
>>  In case there is any confusion, let me restate: You can boot a Bamboo
>>  (PowerPC 440) guest under KVM on a PowerPC 440 host. KVM bypasses
>>  qemu's CPU emulation (TCG), but uses qemu's device emulation.
>>  Therefore, if someone were to implement 440 core emulation in qemu,
>>  you could boot a 440 kernel with qemu without KVM.
>>
>>  Most devices found on 440 SoCs are the same as or very similar to the
>>  devices found on 405 SoCs. Qemu's 440 device emulation isn't perfect,
>>  but because Linux is highly modular, with a modified device tree you
>>  can boot it. See pc-bios/bamboo.dts.
>>
>>  -Hollis
>>
>>  On Sat, Jun 13, 2009 at 10:47 PM, Baojun Wang <wangbj@gmail.com> wrote:
>>  >
>>  > in hw/ppc440.c:
>>  >
>>  >    env = cpu_ppc_init("440EP");
>>  >    if (!env && kvm_enabled()) {
>>  >        /* XXX Since qemu doesn't yet emulate 440, we just say it's a 405.
>>  >         * Since KVM doesn't use qemu's CPU emulation it seems to be working
>>  >         * OK. */
>>  >        env = cpu_ppc_init("405");
>>  >    }
>>  >    if (!env) {
>>  >        fprintf(stderr, "Unable to initialize CPU!\n");
>>  >        exit(1);
>>  >    }
>>  >
>>  > also in hw/ppc.c:
>>  >
>>  > I can find ppc40x_irq_init/e500_irq_init(used mpc8544ds), but there is
>>  > no ppcbooke_irq_init? It seems hw/ppc405_uc.c is emulation for DCRs,
>>  > PLB, DMA, GPIO, I2C.., but there is no hw/ppc44x_uc.c.
>>  >
>>  > the qemu source I used is 0.10.5.
>>  >
>>  > Also in ppc/translate_init.c, there lots of CONFIG_USER_ONLY, but I
>>  > many of them are DEBUG or CACHE related SPR emulation, and since qemu
>>  > doesn't emulate cache, I think it's OK.
>>  >
>>  >  Thanks,
>>  > Wang
>>  >
>>  > On Sun, Jun 14, 2009 at 1:47 AM, Hollis Blanchard<hollis@penguinppc.org> wrote:
>>  > > On Fri, Jun 12, 2009 at 10:48 AM, Blue Swirl <blauwirbel@gmail.com> wrote:
>>  > >>
>>  > >> On 6/11/09, Baojun Wang <wangbj@gmail.com> wrote:
>>  > >> > could qemu emulate some board like bamboo (without kvm) or MPC8544ds
>>  > >> > now? Thanks
>>  > >>
>>  > >> Yes, if someone adds emulation for these devices: UIC, PLB, DMA, POB,
>>  > >> EBC, IIC, ZMII. Maybe some are not needed in all cases.
>>  > >
>>  > > No, qemu still doesn't emulate Book E cores, such as the PowerPC 440 in a
>>  > > Bamboo board.
>>  > >
>>  > > UIC is of course emulated, otherwise KVM guests on 440 wouldn't get very
>>  > > far. :) Enough 440 SoC devices are emulated to support Linux boot with a
>>  > > properly stripped device tree.
>>  > >
>>  > > -Hollis
>>  > >
>>
>