Re: [Qemu-devel] [PATCH for 3.2 v2 0/7] hw/arm/bcm2835: Add basic support for cprman (clock subsystem)

[Guenter Roeck]

On 11/2/18 12:48 AM, Philippe Mathieu-Daudé wrote:
> On Fri, Nov 2, 2018 at 8:32 AM Philippe Mathieu-Daudé <address@hidden> wrote:
> > Hi Guenter,
> >
> > On Fri, Nov 2, 2018 at 3:52 AM Guenter Roeck <address@hidden> wrote:
> > > On 11/1/18 5:12 PM, Philippe Mathieu-Daudé wrote:
> > > > Hi,
> > > >
> > > > This series is a mix of a previous work I had for the raspi, and a patch from
> > > > Guenter: https://lists.gnu.org/archive/html/qemu-devel/2018-07/msg03153.html
> > > >
> > > > The final patch keep Guenter ideas and comments, but is mostly a rewrite.
> > > > I dropped the A2W code from this work, it doesn't seems unuseful to me.
> > > >
> > > > Guenter can you test this series?
> > >
> > > arm/raspi2 works, but aarch64/raspi3 stalls.
> >
> > Thanks for testing it!
> >
> > So I suppose the A2W is required. And I'm probably using a too old kernel,
> > I'm using the Buster preview following Peter's post [1]:
> >
> > [    0.000000] Linux version 4.14.0-3-arm64
> > (address@hidden) (gcc version 7.2.0 (Debian 7.2.0-18))
> > #1 SMP Debian 4.14.12-2 (2018-01-06)
> > [    0.000000] Machine model: Raspberry Pi 3 Model B
> > [...]
> > [    8.044215] systemd[1]: Detected architecture arm64.
> > Welcome to Debian GNU/Linux buster/sid!
> >
> > Debian GNU/Linux buster/sid rpi3 ttyAMA0
> >
> > rpi3 login: root
> > Password:
> > Linux rpi3 4.14.0-3-arm64 #1 SMP Debian 4.14.12-2 (2018-01-06) aarch64
> > address@hidden:~#
> >
> > I'll look for a newer kernel.
>
> I'm a bit confuse since I can boot a 4.19 kernel:
>
> [    0.000000] Booting Linux on physical CPU 0x0000000000 [0x410fd034]
> [    0.000000] Linux version 4.19.0 (address@hidden) (gcc version
> 6.3.0 20170516 (Debian 6.3.0-18)) #1 SMP PREEMPT Wed Mar 1 20:57:29
> UTC 2017
> [    0.000000] Machine model: Raspberry Pi 3 Model B
> [    0.000000] earlycon: pl11 at MMIO 0x000000003f201000 (options '')
> [    0.000000] bootconsole [pl11] enabled
> ...
> [    2.722577] Freeing unused kernel memory: 5696K
> [    2.723256] Run /init as init process
> Loading, please wait...
> starting version 236
> ...
> address@hidden:~# uname -a
> Linux rpi3 4.19.0 #1 SMP PREEMPT Wed Mar 1 20:57:29 UTC 2017 aarch64 GNU/Linux
>
> > BTW I use these QEMU command line options while testing:
> >
> > qemu-system-aarch64 \
> >    -d unimp,guest_errors \
> >    -trace bcm2835_cprman_rd_\* -trace bcm2835_cprman_wr_\* \
> >    ...
> >
> > And the cmdline suggested by Peter:
> >
> >    -append "rw earlycon=pl011,0x3f201000 console=ttyAMA0 loglevel=8
> > root=/dev/mmcblk0p2 fsck.repair=yes net.ifnames=0 rootwait memtest=1"
> >
> > [1] 
> > https://translatedcode.wordpress.com/2018/04/25/debian-on-qemus-raspberry-pi-3-model/
> >
> > > [   45.683302] Run /sbin/init as init process
>
> init is ran way after A2W register accesses, so I doubt they are the
> problem here.
>
> Can you provide me your testing setup?

-append 'earlycon=uart8250,mmio32,0x3f215040 rdinit=/sbin/init panic=-1 
console=ttyS1,115200'

On raspi3, ttyAMA0 can not be used as console because it is connected to 
something else.
I can boot if I use ttyAMA0 as console. Comparing the log output with the 
output when
using my original patch, tt looks like ttyS1 doesn't come up.

Hope this helps,
Guenter