[PATCH v2] arm: imx: imx8m: soc: Add support for 'boot_device' and 'boot_instance' environment variablesAdd setup_boot_mode for imx8m

[Fabio Estevam]

Hi William,

The Subject line ended up super long.

On Wed, Dec 3, 2025 at 7:02 AM William MARTIN <william.martin at muxen.fr> wrote:
>
> Some SoCs have supports for 'boot_device' and 'boot_instance' environment
> variable. Those variables help to choose the right boot media during the
> execution of the boot command.
>
> The i.MX8M SoC doesn't have support for those variables but provides
> internally all the needed information to create those variables.
>
> Fill this lack adding support for those variables in the i.MX8M SoC.


Peng/Ye Li,

Could you please help review this patch?

Thanks

>
> Signed-off-by: William MARTIN <william.martin at muxen.fr>
> ---
>  arch/arm/mach-imx/imx8m/soc.c | 67 +++++++++++++++++++++++++++++++++++
>  1 file changed, 67 insertions(+)
>
> diff --git a/arch/arm/mach-imx/imx8m/soc.c b/arch/arm/mach-imx/imx8m/soc.c
> index 1fe083ae94f..f39f2e90e55 100644
> --- a/arch/arm/mach-imx/imx8m/soc.c
> +++ b/arch/arm/mach-imx/imx8m/soc.c
> @@ -1472,6 +1472,71 @@ void reset_cpu(void)
>  #endif
>
>  #if IS_ENABLED(CONFIG_ARCH_MISC_INIT)
> +static void setup_boot_mode(void)
> +{
> +       enum boot_device dev = get_boot_device();
> +
> +       log_debug("setup_boot_mode = %u\n", dev);
> +
> +       switch (dev) {
> +       case USB_BOOT:
> +               env_set("boot_device", "usb");
> +               env_set("boot_instance", "0");
> +               break;
> +
> +       case QSPI_BOOT:
> +               env_set("boot_device", "spi-nand");
> +               env_set("boot_instance", "0");
> +               break;
> +
> +       case SPI_NOR_BOOT:
> +               env_set("boot_device", "nor");
> +               env_set("boot_instance", "0");
> +               break;
> +
> +       case NAND_BOOT:
> +               env_set("boot_device", "nand");
> +               env_set("boot_instance", "0");
> +               break;
> +
> +       case SD1_BOOT:
> +               env_set("boot_device", "sdcard");
> +               env_set("boot_instance", "1");
> +               break;
> +
> +       case SD2_BOOT:
> +               env_set("boot_device", "sdcard");
> +               env_set("boot_instance", "2");
> +               break;
> +
> +       case SD3_BOOT:
> +               env_set("boot_device", "sdcard");
> +               env_set("boot_instance", "3");
> +               break;
> +
> +       case MMC1_BOOT:
> +               env_set("boot_device", "mmc");
> +               env_set("boot_instance", "1");
> +               break;
> +
> +       case MMC2_BOOT:
> +               env_set("boot_device", "mmc");
> +               env_set("boot_instance", "2");
> +               break;
> +
> +       case MMC3_BOOT:
> +               env_set("boot_device", "mmc");
> +               env_set("boot_instance", "3");
> +               break;
> +
> +       default:
> +               env_set("boot_device", "invalid");
> +               env_set("boot_instance", "");
> +               log_err("unexpected boot mode = %x\n", dev);
> +               break;
> +       }
> +}
> +
>  int arch_misc_init(void)
>  {
>         if (IS_ENABLED(CONFIG_FSL_CAAM)) {
> @@ -1483,6 +1548,8 @@ int arch_misc_init(void)
>                         printf("Failed to initialize caam_jr: %d\n", ret);
>         }
>
> +       setup_boot_mode();
> +
>         return 0;
>  }
>  #endif
> --
> 2.47.3
>