Re: [PATCH] docs/system/arm/orangepi: add instructions for resizing SD image to power of two

[Philippe Mathieu-Daudé]

On 7/12/20 8:37 PM, Niek Linnenbank wrote:
> SD cards need to have a size of a power of two. This commit updates
> the Orange Pi machine documentation to include instructions for
> resizing downloaded images using the qemu-img command.
> 
> Signed-off-by: Niek Linnenbank <nieklinnenbank@gmail.com>
> ---
>  docs/system/arm/orangepi.rst | 16 +++++++++++++---
>  1 file changed, 13 insertions(+), 3 deletions(-)
> 
> diff --git a/docs/system/arm/orangepi.rst b/docs/system/arm/orangepi.rst
> index c41adad488..6f23907fb6 100644
> --- a/docs/system/arm/orangepi.rst
> +++ b/docs/system/arm/orangepi.rst
> @@ -127,6 +127,16 @@ can be downloaded from:
>  Alternatively, you can also choose to build you own image with buildroot
>  using the orangepi_pc_defconfig. Also see https://buildroot.org for more 
> information.
>  
> +When using an image as an SD card, it must be resized to a power of two. 
> This can be
> +done with the qemu-img command. It is recommended to only increase the image 
> size
> +instead of shrinking it to a power of two, to avoid loss of data. For 
> example,
> +to prepare a downloaded Armbian image, first extract it and then increase
> +its size to one gigabyte as follows:
> +
> +.. code-block:: bash
> +
> +  $ qemu-img resize Armbian_19.11.3_Orangepipc_bionic_current_5.3.9.img 1G
> +
>  You can choose to attach the selected image either as an SD card or as USB 
> mass storage.
>  For example, to boot using the Orange Pi PC Debian image on SD card, simply 
> add the -sd
>  argument and provide the proper root= kernel parameter:
> @@ -213,12 +223,12 @@ Next, unzip the NetBSD image and write the U-Boot 
> binary including SPL using:
>    $ dd if=/path/to/u-boot-sunxi-with-spl.bin of=armv7.img bs=1024 seek=8 
> conv=notrunc
>  
>  Finally, before starting the machine the SD image must be extended such
> -that the NetBSD kernel will not conclude the NetBSD partition is larger than
> -the emulated SD card:
> +that the size of the SD image is a power of two and that the NetBSD kernel
> +will not conclude the NetBSD partition is larger than the emulated SD card:
>  
>  .. code-block:: bash
>  
> -  $ dd if=/dev/zero bs=1M count=64 >> armv7.img
> +  $ qemu-img resize armv7.img 2G
>  
>  Start the machine using the following command:
>  
> 

Thanks!

Reviewed-by: Philippe Mathieu-Daudé <f4bug@amsat.org>