Re: [PATCH 2/2] hw/sd/sdcard: Do not allow invalid SD card sizes

[Niek Linnenbank <nieklinnenbank@gmail.com>]

[-- Attachment #1: Type: text/plain, Size: 2053 bytes --]

On Thu, Jul 9, 2020 at 4:15 PM Peter Maydell <peter.maydell@linaro.org>
wrote:

> On Thu, 9 Jul 2020 at 14:56, Philippe Mathieu-Daudé <f4bug@amsat.org>
> wrote:
> >
> > On 7/7/20 10:29 PM, Niek Linnenbank wrote:
> > > So I manually copy & pasted the change into hw/sd/sd.c to test it.
> > > It looks like the check works, but my concern is that with this change,
> > > we will be getting this error on 'off-the-shelf' images as well.
> > > For example, the latest Raspbian image size also isn't a power of two:
> > >
> > > $ ./arm-softmmu/qemu-system-arm -M raspi2 -sd
> > > ~/Downloads/2020-05-27-raspios-buster-lite-armhf.img -nographic
> > > WARNING: Image format was not specified for
> > > '/home/me/Downloads/2020-05-27-raspios-buster-lite-armhf.img' and
> > > probing guessed raw.
> > >          Automatically detecting the format is dangerous for raw
> images,
> > > write operations on block 0 will be restricted.
> > >          Specify the 'raw' format explicitly to remove the
> restrictions.
> > > qemu-system-arm: Invalid SD card size: 1.73 GiB (expecting at least 2
> GiB)
> > >
> > > If we do decide that the change is needed, I would like to propose that
> > > we also give the user some instructions
> > > on how to fix it, maybe some 'dd' command?
> >
> > On POSIX we can suggest to use 'truncate -s 2G' from coreutils.
> > This is not in the default Darwin packages.
> > On Windows I have no clue.
>
> dd/truncate etc won't work if the image file is not raw (eg if
> it's qcow2). The only chance you have of something that's actually
> generic would probably involve "qemu-img resize". But I'm a bit
> wary of having an error message that recommends that, because
> what if we got it wrong?
>

Yeah good point Peter, I see what you mean. As I wrote to Philippe,
i'll try to make a small patch with some instructions in the OrangePi board
documentation,
so then we'll at least have something there to help the user.

Regards,
Niek


>
> thanks
> -- PMM
>


-- 
Niek Linnenbank

[-- Attachment #2: Type: text/html, Size: 3008 bytes --]