Re: [PATCH v5 01/11] hw: arm: Add bananapi M2-Ultra and allwinner-r40 support

[Peter Maydell]

On Sat, 17 Jun 2023 at 17:29, Guenter Roeck <linux@roeck-us.net> wrote:
>
> Hi,
>
> On Tue, May 23, 2023 at 06:04:58PM +0800, qianfanguijin@163.com wrote:
> > From: qianfan Zhao <qianfanguijin@163.com>
> >
> > Allwinner R40 (sun8i) SoC features a Quad-Core Cortex-A7 ARM CPU,
> > and a Mali400 MP2 GPU from ARM. It's also known as the Allwinner T3
> > for In-Car Entertainment usage, A40i and A40pro are variants that
> > differ in applicable temperatures range (industrial and military).
> >
> > Signed-off-by: qianfan Zhao <qianfanguijin@163.com>
> > Reviewed-by: Niek Linnenbank <nieklinnenbank@gmail.com>
>
> I tried this in mainline linux with the following command.
>
> qemu-system-arm -M bpim2u \
>         -kernel arch/arm/boot/zImage -no-reboot \
>         -snapshot -drive file=rootfs-armv7a.ext2,format=raw,if=sd \
>         -nic user \
>         --append "root=/dev/mmcblk0 rootwait console=ttyS0,115200" \
>         -dtb arch/arm/boot/dts/sun8i-r40-bananapi-m2-ultra.dtb \
>         -nographic -monitor null -serial stdio
>
> Main problem is that the SD card gets instantiated randomly to
> mmc0, mmc1, or mmc2, making it all but impossible to specify a
> root file system device. The non-instantiated cards are always
> reported as non-removable, including mmc0. Example:
>
> mmc0: Failed to initialize a non-removable card

Do you mean that QEMU randomly connects the SD card to
a different MMC controller each time, or that Linux is
randomly assigning mmc0 to a different MMC controller each
time ?

thanks
-- PMM