Re: [Qemu-devel] PowerPC 440 support

[Blue Swirl <blauwirbel@gmail.com>]

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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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