[PATCH] lib/flash: Check if the partition is signed

[Samuel Mendoza-Jonas]

On Thu, 2018-11-01 at 14:45 +1100, Samuel Mendoza-Jonas wrote:
> In more recent firmware images built by op-build the VERSION partition
> is signed, and includes a 'secure header'. Check for this and skip it if
> found so we parse the version strings properly.
> 
> Signed-off-by: Samuel Mendoza-Jonas <sam at mendozajonas.com>

Merged as 6a9c33fe

> ---
>  lib/flash/flash.c | 16 ++++++++++++++++
>  1 file changed, 16 insertions(+)
> 
> diff --git a/lib/flash/flash.c b/lib/flash/flash.c
> index b7e5b88b..804d9d2c 100644
> --- a/lib/flash/flash.c
> +++ b/lib/flash/flash.c
> @@ -31,6 +31,8 @@
>  #include <libflash/file.h>
>  #include <libflash/ecc.h>
>  
> +#define SECURE_BOOT_HEADERS_SIZE 4096
> +#define ROM_MAGIC_NUMBER 0x17082011
>  
>  struct flash_info {
>  	/* Device information */
> @@ -148,6 +150,16 @@ out:
>  	return NULL;
>  }
>  
> +/* See stb_is_container() in Skiboot */
> +static bool is_signed(char *buffer, uint32_t len)
> +{
> +	if (!buffer || len <= SECURE_BOOT_HEADERS_SIZE)
> +		return false;
> +	if (be32_to_cpu((uint32_t *)buffer) != ROM_MAGIC_NUMBER)
> +		return false;
> +	return true;
> +}
> +
>  int flash_parse_version(void *ctx, char ***versions, bool current)
>  {
>  	char *saveptr, *tok,  **tmp, *buffer;
> @@ -182,6 +194,10 @@ int flash_parse_version(void *ctx, char ***versions, bool current)
>  		goto out;
>  	}
>  
> +	/* Check if this partition is signed */
> +	if (is_signed(buffer, len))
> +		buffer += SECURE_BOOT_HEADERS_SIZE;
> +
>  	/* open-power-platform */
>  	tok = strtok_r(buffer, delim, &saveptr);
>  	if (tok) {