Re: [PATCH] mach-k3: move k3_falcon_fdt_fixup out of r5/common.c

[Anshul Dalal <anshuld@ti.com>]

On Thu Mar 12, 2026 at 5:34 PM IST, Anshul Dalal wrote:
> k3_falcon_fdt_fixup is used to perform fdt fixups at runtime in falcon
> mode such as adding bootargs. Currently the function is only accessible
> to the R5 SPL but could be useful for A53 SPL based falcon mode setups
> as well.
>
> Therefore this patch moves the function from r5/common.c to common.c.
>

Btw for testing purposes, I had used the following config fragment with
rootfs from the default tisdk image on am62x[1]:

# Enable falcon mode
CONFIG_SPL_OS_BOOT=y
CONFIG_SPL_OS_BOOT_SECURE=y
# We use envs for setting bootargs
CONFIG_SPL_ENV_SUPPORT=y
# Allows for the SPL to detect UUID for kernel's rootfs
CONFIG_SPL_PARTITION_UUIDS=y
# Perform FDT fixups from SPL
CONFIG_OF_SYSTEM_SETUP=y
# We use the rootfs (i.e partition 2) for booting which is ext4 not FAT
CONFIG_SYS_MMCSD_FS_BOOT=y
CONFIG_SYS_MMCSD_FS_BOOT_PARTITION=2
CONFIG_SPL_FS_EXT4=y
CONFIG_SPL_FS_LOAD_KERNEL_NAME="boot/fitImage"
CONFIG_SPL_LOAD_FIT=y
# Used as the 2MiB aligned load address for kernel
CONFIG_SPL_HAS_LOAD_FIT_ADDRESS=y
CONFIG_SYS_LOAD_ADDR=0x82000000
CONFIG_SPL_STACK_R_ADDR=0x88000000
CONFIG_SPL_LOAD_FIT_ADDRESS=0x82000000
CONFIG_SPL_PAYLOAD_ARGS_ADDR=0x88000000
CONFIG_SPL_STACK_R_MALLOC_SIMPLE_LEN=0x2700000
CONFIG_SPL_GZIP=y
# Disable all unsupported boot media to save space
# CONFIG_SPL_SYS_MMCSD_RAW_MODE is not set
# CONFIG_SPL_SPI_FLASH_SUPPORT is not set
# CONFIG_SPL_YMODEM_SUPPORT is not set
# CONFIG_SUPPORT_EMMC_BOOT is not set
# CONFIG_SPL_NAND_SUPPORT is not set
# CONFIG_SPL_NOR_SUPPORT is not set
# CONFIG_SPL_RAM_DEVICE is not set
# CONFIG_SPL_FS_FAT is not set

I was wondering if it makes sense to add this config fragment to the
tree along with documentation for falcon mode from A53 SPL for K3
platforms?

[1]: https://www.ti.com/tool/PROCESSOR-SDK-AM62X

> Signed-off-by: Anshul Dalal <anshuld@ti.com>
> ---
>  arch/arm/mach-k3/common.c    | 80 ++++++++++++++++++++++++++++++++++++++++++++
>  arch/arm/mach-k3/common.h    |  5 ++-
>  arch/arm/mach-k3/r5/common.c | 77 ------------------------------------------
>  3 files changed, 84 insertions(+), 78 deletions(-)
>
> diff --git a/arch/arm/mach-k3/common.c b/arch/arm/mach-k3/common.c
> index 2f3df5519c5..b0a75988714 100644
> --- a/arch/arm/mach-k3/common.c
> +++ b/arch/arm/mach-k3/common.c
> @@ -457,6 +457,83 @@ static __maybe_unused void k3_dma_remove(void)
>  		pr_warn("DMA Device not found (err=%d)\n", rc);
>  }
>  
> +static int k3_falcon_fdt_add_bootargs(void *fdt)
> +{
> +	struct disk_partition info;
> +	struct blk_desc *dev_desc;
> +	char bootmedia[32];
> +	char bootpart[32];
> +	char str[256];
> +	int ret;
> +
> +	strlcpy(bootmedia, env_get("boot"), sizeof(bootmedia));
> +	strlcpy(bootpart, env_get("bootpart"), sizeof(bootpart));
> +	ret = blk_get_device_part_str(bootmedia, bootpart, &dev_desc, &info, 0);
> +	if (ret < 0) {
> +		printf("%s: Failed to get part details for %s %s [%d]\n",
> +		       __func__, bootmedia, bootpart, ret);
> +		return ret;
> +	}
> +
> +	if (!CONFIG_IS_ENABLED(PARTITION_UUIDS)) {
> +		printf("ERROR: Failed to find rootfs PARTUUID\n");
> +		printf("%s: CONFIG_SPL_PARTITION_UUIDS not enabled\n",
> +		       __func__);
> +		return -EOPNOTSUPP;
> +	}
> +
> +	snprintf(str, sizeof(str), "console=%s root=PARTUUID=%s rootwait",
> +		 env_get("console"), disk_partition_uuid(&info));
> +
> +	ret = fdt_find_and_setprop(fdt, "/chosen", "bootargs", str,
> +				   strlen(str) + 1, 1);
> +	if (ret) {
> +		printf("%s: Could not set bootargs: %s\n", __func__,
> +		       fdt_strerror(ret));
> +		return ret;
> +	}
> +
> +	debug("%s: Set bootargs to: %s\n", __func__, str);
> +	return 0;
> +}
> +
> +int k3_falcon_fdt_fixup(void *fdt)
> +{
> +	int ret;
> +
> +	if (!fdt)
> +		return -EINVAL;
> +
> +	fdt_set_totalsize(fdt, fdt_totalsize(fdt) + CONFIG_SYS_FDT_PAD);
> +
> +	if (fdt_path_offset(fdt, "/chosen/bootargs") < 0) {
> +		ret = k3_falcon_fdt_add_bootargs(fdt);
> +
> +		if (ret)
> +			return ret;
> +	}
> +
> +	if (IS_ENABLED(CONFIG_OF_BOARD_SETUP)) {
> +		ret = ft_board_setup(fdt, gd->bd);
> +		if (ret) {
> +			printf("%s: Failed in board setup: %s\n", __func__,
> +			       fdt_strerror(ret));
> +			return ret;
> +		}
> +	}
> +
> +	if (IS_ENABLED(CONFIG_OF_SYSTEM_SETUP)) {
> +		ret = ft_system_setup(fdt, gd->bd);
> +		if (ret) {
> +			printf("%s: Failed in system setup: %s\n", __func__,
> +			       fdt_strerror(ret));
> +			return ret;
> +		}
> +	}
> +
> +	return 0;
> +}
> +
>  void spl_perform_arch_fixups(struct spl_image_info *spl_image)
>  {
>  	void *fdt = spl_image_fdt_addr(spl_image);
> @@ -465,6 +542,9 @@ void spl_perform_arch_fixups(struct spl_image_info *spl_image)
>  		return;
>  
>  	fdt_fixup_reserved(fdt);
> +
> +	if (IS_ENABLED(CONFIG_SPL_OS_BOOT))
> +		k3_falcon_fdt_fixup(fdt);
>  }
>  
>  void spl_board_prepare_for_boot(void)
> diff --git a/arch/arm/mach-k3/common.h b/arch/arm/mach-k3/common.h
> index e970076d08e..466ad22f895 100644
> --- a/arch/arm/mach-k3/common.h
> +++ b/arch/arm/mach-k3/common.h
> @@ -61,10 +61,13 @@ 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)
> +#if IS_ENABLED(CONFIG_SPL_OS_BOOT_SECURE)
> +int k3_falcon_fdt_fixup(void *fdt);
> +#if !IS_ENABLED(CONFIG_ARM64)
>  int k3_r5_falcon_bootmode(void);
>  int k3_r5_falcon_prep(void);
>  #endif
> +#endif
>  
>  #if (IS_ENABLED(CONFIG_K3_QOS))
>  void setup_qos(void);
> diff --git a/arch/arm/mach-k3/r5/common.c b/arch/arm/mach-k3/r5/common.c
> index 03638366046..484d96f9536 100644
> --- a/arch/arm/mach-k3/r5/common.c
> +++ b/arch/arm/mach-k3/r5/common.c
> @@ -406,83 +406,6 @@ int k3_r5_falcon_bootmode(void)
>  		return BOOT_DEVICE_NOBOOT;
>  }
>  
> -static int k3_falcon_fdt_add_bootargs(void *fdt)
> -{
> -	struct disk_partition info;
> -	struct blk_desc *dev_desc;
> -	char bootmedia[32];
> -	char bootpart[32];
> -	char str[256];
> -	int ret;
> -
> -	strlcpy(bootmedia, env_get("boot"), sizeof(bootmedia));
> -	strlcpy(bootpart, env_get("bootpart"), sizeof(bootpart));
> -	ret = blk_get_device_part_str(bootmedia, bootpart, &dev_desc, &info, 0);
> -	if (ret < 0) {
> -		printf("%s: Failed to get part details for %s %s [%d]\n",
> -		       __func__, bootmedia, bootpart, ret);
> -		return ret;
> -	}
> -
> -	if (!CONFIG_IS_ENABLED(PARTITION_UUIDS)) {
> -		printf("ERROR: Failed to find rootfs PARTUUID\n");
> -		printf("%s: CONFIG_SPL_PARTITION_UUIDS not enabled\n",
> -		       __func__);
> -		return -EOPNOTSUPP;
> -	}
> -
> -	snprintf(str, sizeof(str), "console=%s root=PARTUUID=%s rootwait",
> -		 env_get("console"), disk_partition_uuid(&info));
> -
> -	ret = fdt_find_and_setprop(fdt, "/chosen", "bootargs", str,
> -				   strlen(str) + 1, 1);
> -	if (ret) {
> -		printf("%s: Could not set bootargs: %s\n", __func__,
> -		       fdt_strerror(ret));
> -		return ret;
> -	}
> -
> -	debug("%s: Set bootargs to: %s\n", __func__, str);
> -	return 0;
> -}
> -
> -static int k3_falcon_fdt_fixup(void *fdt)
> -{
> -	int ret;
> -
> -	if (!fdt)
> -		return -EINVAL;
> -
> -	fdt_set_totalsize(fdt, fdt_totalsize(fdt) + CONFIG_SYS_FDT_PAD);
> -
> -	if (fdt_path_offset(fdt, "/chosen/bootargs") < 0) {
> -		ret = k3_falcon_fdt_add_bootargs(fdt);
> -
> -		if (ret)
> -			return ret;
> -	}
> -
> -	if (IS_ENABLED(CONFIG_OF_BOARD_SETUP)) {
> -		ret = ft_board_setup(fdt, gd->bd);
> -		if (ret) {
> -			printf("%s: Failed in board setup: %s\n", __func__,
> -			       fdt_strerror(ret));
> -			return ret;
> -		}
> -	}
> -
> -	if (IS_ENABLED(CONFIG_OF_SYSTEM_SETUP)) {
> -		ret = ft_system_setup(fdt, gd->bd);
> -		if (ret) {
> -			printf("%s: Failed in system setup: %s\n", __func__,
> -			       fdt_strerror(ret));
> -			return ret;
> -		}
> -	}
> -
> -	return 0;
> -}
> -
>  int k3_r5_falcon_prep(void)
>  {
>  	struct spl_image_loader *loader, *drv;
>
> ---
> base-commit: 8bc2a5196c1c0bb5dbdaca073323da0015a0de37
> change-id: 20260312-move_falcon_fixups_to_common-34b602114608
>
> Best regards,