[PATCH v9 3/8] mach-k3: common: enable falcon mode from R5 SPL

[Andrew Davis]

On 10/30/25 12:19 AM, Anshul Dalal wrote:
> We use the spl_board_prepare_for_boot hook to call k3_r5_falcon_prep
> which is ran after tispl is loaded but before jump_to_image.
> 
> In k3_r5_falcon_prep, we find the boot media and load the kernel FIT
> just as standard secure falcon mode (since spl_start_uboot returns 0
> now). Once the kernel and args are loaded.
> 
> Now when the flow goes to jump_to_image, we do the regular pre-jump
> procedure and jump to TFA which jumps to the kernel directly since we
> have already loaded the kernel and dtb at their respective addresses
> (PRELOADED_BL33_BASE and K3_HW_CONFIG_BASE).
> 
> Signed-off-by: Anshul Dalal <anshuld at ti.com>
> ---
>   arch/arm/mach-k3/common.c    |  8 +++++++
>   arch/arm/mach-k3/common.h    |  4 ++++
>   arch/arm/mach-k3/r5/common.c | 45 ++++++++++++++++++++++++++++++++++++
>   3 files changed, 57 insertions(+)
> 
> diff --git a/arch/arm/mach-k3/common.c b/arch/arm/mach-k3/common.c
> index 04a0f232d84..c446d1c47fd 100644
> --- a/arch/arm/mach-k3/common.c
> +++ b/arch/arm/mach-k3/common.c
> @@ -360,6 +360,14 @@ void spl_perform_arch_fixups(struct spl_image_info *spl_image)
>   
>   void spl_board_prepare_for_boot(void)
>   {
> +#if IS_ENABLED(CONFIG_SPL_OS_BOOT_SECURE) && !IS_ENABLED(CONFIG_ARM64)
> +	int ret;
> +
> +	ret = k3_r5_falcon_prep();
> +	if (ret)
> +		panic("%s: Failed to boot in falcon mode: %d\n", __func__, ret);
> +#endif /* falcon mode on R5 SPL */
> +
>   #if !(defined(CONFIG_SYS_ICACHE_OFF) && defined(CONFIG_SYS_DCACHE_OFF))
>   	dcache_disable();
>   #endif
> diff --git a/arch/arm/mach-k3/common.h b/arch/arm/mach-k3/common.h
> index 52d3faaab5c..5807d358464 100644
> --- a/arch/arm/mach-k3/common.h
> +++ b/arch/arm/mach-k3/common.h
> @@ -52,6 +52,10 @@ void do_board_detect(void);
>   void ti_secure_image_check_binary(void **p_image, size_t *p_size);
>   int shutdown_mcu_r5_core1(void);
>   
> +#if IS_ENABLED(CONFIG_SPL_OS_BOOT_SECURE) && !IS_ENABLED(CONFIG_ARM64)
> +int k3_r5_falcon_bootmode(void);
> +#endif
> +
>   #if (IS_ENABLED(CONFIG_K3_QOS))
>   void setup_qos(void);
>   #else
> diff --git a/arch/arm/mach-k3/r5/common.c b/arch/arm/mach-k3/r5/common.c
> index 6269b33f66b..439dd92ef54 100644
> --- a/arch/arm/mach-k3/r5/common.c
> +++ b/arch/arm/mach-k3/r5/common.c
> @@ -376,3 +376,48 @@ void board_fit_image_post_process(const void *fit, int node, void **p_image,
>   	}
>   }
>   #endif
> +
> +#ifdef CONFIG_SPL_OS_BOOT_SECURE
> +
> +static bool tifalcon_loaded;

Not strictly needed as statics will default to 0, assigning false
here makes it more clear what the starting value should be,

static bool tifalcon_loaded = false;

> +
> +int spl_start_uboot(void)
> +{
> +	/* If tifalcon.bin is not loaded, proceed to regular boot */
> +	if (!tifalcon_loaded)
> +		return 1;
> +
> +	/* Boot to linux on R5 SPL with tifalcon.bin loaded */
> +		return 0;

Extra indent tab here.

> +}
> +
> +int k3_r5_falcon_prep(void)
> +{
> +	struct spl_image_loader *loader, *drv;
> +	struct spl_image_info kernel_image;
> +	struct spl_boot_device bootdev;
> +	int ret = -ENXIO, n_ents;
> +
> +	tifalcon_loaded = true;

Should this be set down after we make sure loading doesn't fail?

> +	memset(&kernel_image, '\0', sizeof(kernel_image));
> +	drv = ll_entry_start(struct spl_image_loader, spl_image_loader);
> +	n_ents = ll_entry_count(struct spl_image_loader, spl_image_loader);
> +	bootdev.boot_device = spl_boot_device();
> +
> +	for (loader = drv; loader != drv + n_ents; loader++) {
> +		if (bootdev.boot_device != loader->boot_device)
> +			continue;
> +		if (loader) {

If loader is NULL, the if above containing loader->boot_device would have
already null pointer deref crashed. You might want to move this check up
into the if check above.

Andrew

> +			printf("Loading falcon payload from %s\n",
> +			       spl_loader_name(loader));
> +			ret = loader->load_image(&kernel_image, &bootdev);
> +			if (ret)
> +				continue;
> +
> +			return 0;
> +		}
> +	}
> +
> +	return ret;
> +}
> +#endif