Re: [kvm-unit-tests PATCH] lib/devicetree: Support 64 bit addresses for the initrd

[Andrew Jones <drjones@xxxxxxxxxx>]

On Mon, Feb 14, 2022 at 12:05:06PM +0000, Alexandru Elisei wrote:
> The "linux,initrd-start" and "linux,initrd-end" properties encode the start
> and end address of the initrd. The size of the address is encoded in the
> root node #address-cells property and can be 1 cell (32 bits) or 2 cells
> (64 bits). Add support for parsing a 64 bit address.
> 
> Signed-off-by: Alexandru Elisei <alexandru.elisei@xxxxxxx>
> ---
>  lib/devicetree.c | 18 +++++++++++++-----
>  1 file changed, 13 insertions(+), 5 deletions(-)
> 
> diff --git a/lib/devicetree.c b/lib/devicetree.c
> index 409d18bedbba..7cf64309a912 100644
> --- a/lib/devicetree.c
> +++ b/lib/devicetree.c
> @@ -288,7 +288,7 @@ int dt_get_default_console_node(void)
>  int dt_get_initrd(const char **initrd, u32 *size)
>  {
>  	const struct fdt_property *prop;
> -	const char *start, *end;
> +	u64 start, end;
>  	int node, len;
>  	u32 *data;
>  
> @@ -303,7 +303,11 @@ int dt_get_initrd(const char **initrd, u32 *size)
>  	if (!prop)
>  		return len;
>  	data = (u32 *)prop->data;
> -	start = (const char *)(unsigned long)fdt32_to_cpu(*data);
> +	start = fdt32_to_cpu(*data);
> +	if (len == 8) {
> +		data++;
> +		start = (start << 32) | fdt32_to_cpu(*data);
> +	}
>  
>  	prop = fdt_get_property(fdt, node, "linux,initrd-end", &len);
>  	if (!prop) {
> @@ -311,10 +315,14 @@ int dt_get_initrd(const char **initrd, u32 *size)
>  		return len;
>  	}
>  	data = (u32 *)prop->data;
> -	end = (const char *)(unsigned long)fdt32_to_cpu(*data);
> +	end = fdt32_to_cpu(*data);
> +	if (len == 8) {
> +		data++;
> +		end = (end << 32) | fdt32_to_cpu(*data);
> +	}
>  
> -	*initrd = start;
> -	*size = (unsigned long)end - (unsigned long)start;
> +	*initrd = (char *)start;
> +	*size = end - start;
>  
>  	return 0;
>  }
> -- 
> 2.35.1
>

I added this patch on

diff --git a/lib/devicetree.c b/lib/devicetree.c
index 7cf64309a912..fa8399a7513d 100644
--- a/lib/devicetree.c
+++ b/lib/devicetree.c
@@ -305,6 +305,7 @@ int dt_get_initrd(const char **initrd, u32 *size)
        data = (u32 *)prop->data;
        start = fdt32_to_cpu(*data);
        if (len == 8) {
+               assert(sizeof(long) == 8);
                data++;
                start = (start << 32) | fdt32_to_cpu(*data);
        }
@@ -321,7 +322,7 @@ int dt_get_initrd(const char **initrd, u32 *size)
                end = (end << 32) | fdt32_to_cpu(*data);
        }
 
-       *initrd = (char *)start;
+       *initrd = (char *)(unsigned long)start;
        *size = end - start;
 
        return 0;


To fix compilation on 32-bit arm.


And now merged through misc/queue.

Thanks,
drew