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Re: [Qemu-devel] PowerPC 440 support
From: |
Blue Swirl |
Subject: |
Re: [Qemu-devel] PowerPC 440 support |
Date: |
Sun, 14 Jun 2009 23:40:53 +0300 |
On 6/14/09, Hollis Blanchard <address@hidden> 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<address@hidden> 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 <address@hidden> 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 <address@hidden> 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<address@hidden>
> wrote:
> >> > > On Fri, Jun 12, 2009 at 10:48 AM, Blue Swirl <address@hidden> wrote:
> >> > >>
> >> > >> On 6/11/09, Baojun Wang <address@hidden> 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, 2009/06/15