[PATCH 1/4] mach-snapdragon: track boot source

[Neil Armstrong]

On 26/03/2025 18:40, Caleb Connolly wrote:
> Keep track of whether we were loaded via ABL or if U-Boot is running as
> a first-stage bootloader.
> 
> For now we set this based on if we have a valid external FDT or not,
> since it isn't possible to chainload U-Boot from ABL without there being
> an external FDT.
> 
> This will be used to inform the capsule update logic which partition
> U-Boot is flashed to.
> 
> Signed-off-by: Caleb Connolly <caleb.connolly at linaro.org>
> ---
>   arch/arm/mach-snapdragon/board.c     | 25 +++++++++++++++++++++++++
>   arch/arm/mach-snapdragon/qcom-priv.h | 14 ++++++++++++++
>   2 files changed, 39 insertions(+)
> 
> diff --git a/arch/arm/mach-snapdragon/board.c b/arch/arm/mach-snapdragon/board.c
> index deae4d323789eab75d5fe735159b4cd820c02c45..245a963f5321bda3030d3809e1b108f280b3c2b5 100644
> --- a/arch/arm/mach-snapdragon/board.c
> +++ b/arch/arm/mach-snapdragon/board.c
> @@ -36,8 +36,10 @@
>   #include "qcom-priv.h"
>   
>   DECLARE_GLOBAL_DATA_PTR;
>   
> +enum qcom_boot_source qcom_boot_source __section(".data") = 0;
> +
>   static struct mm_region rbx_mem_map[CONFIG_NR_DRAM_BANKS + 2] = { { 0 } };
>   
>   struct mm_region *mem_map = rbx_mem_map;
>   
> @@ -237,8 +239,14 @@ int board_fdt_blob_setup(void **fdtp)
>   
>   	if (ret < 0)
>   		panic("No valid memory ranges found!\n");
>   
> +	/* If we have an external FDT, it can only have come from the Android bootloader. */
> +	if (external_valid)
> +		qcom_boot_source = QCOM_BOOT_SOURCE_ANDROID;
> +	else
> +		qcom_boot_source = QCOM_BOOT_SOURCE_XBL;
> +
>   	debug("ram_base = %#011lx, ram_size = %#011llx\n",
>   	      gd->ram_base, gd->ram_size);
>   
>   	if (internal_valid) {
> @@ -472,8 +480,24 @@ static void configure_env(void)
>   
>   	qcom_set_serialno();
>   }
>   
> +void qcom_show_boot_source(void)
> +{
> +	const char *name = "UNKNOWN";
> +
> +	switch (qcom_boot_source) {
> +	case QCOM_BOOT_SOURCE_ANDROID:
> +		name = "ABL";
> +		break;
> +	case QCOM_BOOT_SOURCE_XBL:
> +		name = "XBL";
> +		break;
> +	}
> +
> +	log_info("U-Boot loaded from %s\n", name);

Can you write to a boot_source env variable ?

> +}
> +
>   void __weak qcom_late_init(void)
>   {
>   }
>   
> @@ -515,8 +539,9 @@ int board_late_init(void)
>   
>   	configure_env();
>   	qcom_late_init();
>   
> +	qcom_show_boot_source();
>   	/* Configure the dfu_string for capsule updates */
>   	qcom_configure_capsule_updates();
>   
>   	return 0;
> diff --git a/arch/arm/mach-snapdragon/qcom-priv.h b/arch/arm/mach-snapdragon/qcom-priv.h
> index 74d39197b89f4e769299b06214c26ee829ecdce0..e5eb4cfbc2b752de799b1407ede69683c81474c1 100644
> --- a/arch/arm/mach-snapdragon/qcom-priv.h
> +++ b/arch/arm/mach-snapdragon/qcom-priv.h
> @@ -2,8 +2,22 @@
>   
>   #ifndef __QCOM_PRIV_H__
>   #define __QCOM_PRIV_H__
>   
> +/**
> + * enum qcom_boot_source - Track where we got loaded from.
> + * Used for capsule update logic.
> + *
> + * @QCOM_BOOT_SOURCE_ANDROID: chainloaded (typically from ABL)
> + * @QCOM_BOOT_SOURCE_XBL: flashed to the XBL or UEFI partition
> + */
> +enum qcom_boot_source {
> +	QCOM_BOOT_SOURCE_ANDROID = 1,
> +	QCOM_BOOT_SOURCE_XBL,
> +};
> +
> +extern enum qcom_boot_source qcom_boot_source;
> +
>   #if IS_ENABLED(CONFIG_EFI_HAVE_CAPSULE_SUPPORT)
>   void qcom_configure_capsule_updates(void);
>   #else
>   void qcom_configure_capsule_updates(void) {}
>