[PATCH 1/2] bootsource: add bootsource instance index variable

[Sascha Hauer]

On 2026-05-20 10:32, Fabian Pfitzner wrote:
> The bootsource instance index variable shows us,
> from which image on the instance we have booted from.
> This is a useful information, when there a multiple boot images contained
> on one flash (e. g. primary and recovery).
> 
> Add a C interface to set and get the bootsource instance:
> 
>     int bootsource_get_instance_index(void);
>     void bootsource_set_instance_index(int index);
> 
> Also export the shell variable "bootsource_instance_index".
> 
> Signed-off-by: Fabian Pfitzner <f.pfitzner at pengutronix.de>
> ---
>  Documentation/user/variables.rst |  1 +
>  common/bootsource.c              | 20 ++++++++++++++++++++
>  include/bootsource.h             | 11 +++++++++++
>  3 files changed, 32 insertions(+)
> 
> diff --git a/Documentation/user/variables.rst b/Documentation/user/variables.rst
> index 61808f1d72de29477b02b53ad11ecf530b4ebc80..c8b34679068cff4356fec306942b85561187652f 100644
> --- a/Documentation/user/variables.rst
> +++ b/Documentation/user/variables.rst
> @@ -112,6 +112,7 @@ of all active variables with special meaning along with a short description:
>    bootargs                         Linux Kernel parameters
>    bootsource                       The source barebox has been booted from
>    bootsource_instance              The instance of the source barebox has been booted from
> +  bootsource_instance_index        Tells us whether we have booted from primary(0) or secondary(1)
>    global.boot.default              default boot order
>    ...
>  
> diff --git a/common/bootsource.c b/common/bootsource.c
> index f608019bb758f820eea19213c75b389df6b4158c..53549d4171ff33bfcdd7436261cd8f4d3598099a 100644
> --- a/common/bootsource.c
> +++ b/common/bootsource.c
> @@ -33,6 +33,7 @@ static const char *bootsource_str[BOOTSOURCE_MAX] = {
>  
>  static enum bootsource bootsource = BOOTSOURCE_UNKNOWN;
>  static int bootsource_instance = BOOTSOURCE_INSTANCE_UNKNOWN;
> +static int bootsource_instance_index = BOOTSOURCE_INSTANCE_INDEX_UNKNOWN;
>  
>  const char *bootsource_to_string(enum bootsource src)
>  {
> @@ -226,6 +227,17 @@ int bootsource_set(enum bootsource src, int instance)
>  	return alias_id;
>  }
>  
> +void bootsource_set_instance_index(int index)
> +{
> +	if (index < 0 || index > 1)
> +		pr_err("Invalid index: %d, expected either 0 or 1", index);
> +
> +	char str[1];
> +
> +	sprintf(str, "%d", index);

The string is too small. You need another byte for the '\0'

Sascha

--
Pengutronix e.K.                           |                             |
Steuerwalder Str. 21                       | http://www.pengutronix.de/  |
31137 Hildesheim, Germany                  | Phone: +49-5121-206917-0    |
Amtsgericht Hildesheim, HRA 2686           | Fax:   +49-5121-206917-5555 |