Re: [ImageBuilder] uboot-script-gen: use size from arm32 zImage header

[Stefano Stabellini <sstabellini@xxxxxxxxxx>]

On Mon, 20 Nov 2023, Michal Orzel wrote:
> Take an example from commit 8bf401c99035 ("uboot-script-gen: use size from
> arm64 Image header") and add support for calculating the effective image
> size from arm32 zImage header.
> 
> Introduce get_image_size() function and use it to to probe the supported
> header magic values and to retrieve the effective image size. Use this
> value in add_size(), whenever it's bigger than the one obtained using
> 'stat -L'.
> 
> Signed-off-by: Michal Orzel <michal.orzel@xxxxxxx>

Acked-by: Stefano Stabellini <sstabellini@xxxxxxxxxx>


> ---
> This patch together with 'bootz' support will allow us to enable testing Xen
> on arm{32,64} in gitlab CI with UBSAN enabled.
> ---
>  scripts/uboot-script-gen | 38 ++++++++++++++++++++++++++++----------
>  1 file changed, 28 insertions(+), 10 deletions(-)
> 
> diff --git a/scripts/uboot-script-gen b/scripts/uboot-script-gen
> index 9e3d86e4743a..078a667c61ab 100755
> --- a/scripts/uboot-script-gen
> +++ b/scripts/uboot-script-gen
> @@ -431,23 +431,41 @@ function device_tree_editing()
>      fi
>  }
>  
> -function add_size()
> +# Read effective image size from a header, which may be larger than the 
> filesize
> +# due to noload sections, e.g. bss.
> +function get_image_size()
>  {
> -    local filename=$1
> -    local size=`stat -L --printf="%s" $filename`
> +    local image=$1
> +    local effective_size=0
>      # Read arm64 header magic 
> (https://www.kernel.org/doc/Documentation/arm64/booting.txt)
> -    local arm64_header_magic=$(od -j 56 -N 4 -t x4 ${filename} | awk 'NR==1 
> {print $2}')
> +    local arm64_header_magic=$(od -j 56 -N 4 -t x4 ${image} | awk 'NR==1 
> {print $2}')
> +    # Read arm32 header magic 
> (http://www.simtec.co.uk/products/SWLINUX/files/booting_article.html)
> +    local arm32_header_magic=$(od -j 36 -N 4 -t x4 ${image} | awk 'NR==1 
> {print $2}')
>  
>      # Check for valid arm64 header magic value 0x644d5241
>      if [ "${arm64_header_magic}" = "644d5241" ]
>      then
> -        # Read effective size, which may be larger than the filesize due to 
> noload sections, e.g. bss
> -        local arm64_header_size=$(od -j 16 -N 8 -t u8 ${filename} | awk 
> 'NR==1 {print $2}')
> +        effective_size=$(od -j 16 -N 8 -t u8 ${image} | awk 'NR==1 {print 
> $2}')
> +    # Check for valid arm32 header magic value 0x016f2818
> +    elif [ "${arm32_header_magic}" = "016f2818" ]
> +    then
> +        local start=$(od -j 40 -N 4 -t u4 ${image} | awk 'NR==1 {print $2}')
> +        local end=$(od -j 44 -N 4 -t u4 ${image} | awk 'NR==1 {print $2}')
> +        effective_size=$(( end - start ))
> +    fi
>  
> -        if [ "${arm64_header_size}" -gt "${size}" ]
> -        then
> -            size=${arm64_header_size}
> -        fi
> +    printf "%u" $effective_size
> +}
> +
> +function add_size()
> +{
> +    local filename=$1
> +    local size=`stat -L --printf="%s" $filename`
> +    local image_size=`get_image_size $filename`
> +
> +    if [ "${image_size}" -gt "${size}" ]
> +    then
> +        size=${image_size}
>      fi
>  
>      memaddr=$(( $memaddr + $size + $offset - 1))
> -- 
> 2.25.1
>