[PATCH 1/2] configs/j721e_{beaglebone64, evm}_defconfig: reduce fastboot buffer

[Kumar, Udit]

On 4/26/2026 7:27 PM, Romain Naour wrote:
> Using Snagboot's Snagflash tool to flash the SD card using
> fastboot-uboot mode on SK-TDA4VM crash u-boot.
> 
> Flashing an image.wic.xz file generated by Yocto doesn't work as
> expected:
> 
> 2026-04-25 16:46:21,134 [INFO] flashed 267296768/267296768 bytes
> 2026-04-25 16:46:21,162 [INFO] Flashing sparse range 10/13
> 2026-04-25 16:46:21,163 [INFO] Flashing to MMC device...
> 
> On the the chunk is bigger that previous one and doesn't fit in the RAM
> memory mapping set by the SoC (TDA4VM)
> 

Thanks for catching this.
Most of TI soc has optee at 0x9e800000 address, so this address should
not be used.

> downloading of 267296768 bytes finished
> MMC write: dev # 1, block # 2101440, count 522064 ... 522064 blocks written: OK
> switch to partitions #0, OK
> mmc1 is current device
> Starting download of 486944768 bytes
> 
> "Synchronous Abort" handler, esr 0x96000046, far 0x9e800000
> Indeed, this memory address (0x9e800000) is "reserved"
> 
> "bdinfo" allows to notice that 0x9e800000 address is actually
> "reserved":
> 
>   memory.count = 0x2
>   memory[0]      [0x80000000-0xffffffff], 0x80000000 bytes, flags: none
>   memory[1]      [0x880000000-0x8ffffffff], 0x80000000 bytes, flags: none
>   reserved.count = 0x4
>   reserved[0]    [0x9e800000-0xa8ffffff], 0xa800000 bytes, flags: no-map
>   reserved[1]    [0xaa000000-0xabbfffff], 0x1c00000 bytes, flags: no-map
>   reserved[2]    [0xfce40b30-0xffffffff], 0x31bf4d0 bytes, flags: no-overwrite
>   reserved[3]    [0x8ffff7000-0x8ffffffff], 0x9000 bytes, flags: no-notify, no-overwrite
> 
> CONFIG_FASTBOOT_BUF_SIZE was initialy set to 0x2F000000 in the u-boot
> configuration for the SK-TDA4VM.
> 
> With SYS_LOAD_ADDR set to 0x82000000, the end of the fastboot buffer is
> at 0xB1000000 and overlap the reserved region[0] and region[1].
> 
> In order to avoid writing the first reserved address (0x9e800000) we
> have to reduce CONFIG_FASTBOOT_BUF_SIZE to 0x1c800000.
> 
> On this platfrom 0x9e800000 is reserved since it's used for optee
> (K3_OPTEE_LOAD_ADDR).
> 
> (Issue initially reported on Snagboot)
> [1] https://github.com/bootlin/snagboot/issues/90
> 

Please have fixes tag

While at this, please do fix for below SOCs

configs/j7200_evm_a72_defconfig:CONFIG_FASTBOOT_BUF_ADDR=0x82000000
configs/j721s2_evm_a72_defconfig:CONFIG_FASTBOOT_BUF_ADDR=0x82000000



> Signed-off-by: Romain Naour <romain.naour at smile.fr>
> ---
>  configs/j721e_beagleboneai64_a72_defconfig | 2 +-
>  configs/j721e_evm_a72_defconfig            | 2 +-
>  2 files changed, 2 insertions(+), 2 deletions(-)
> 
> diff --git a/configs/j721e_beagleboneai64_a72_defconfig b/configs/j721e_beagleboneai64_a72_defconfig
> index dc76504eb83..abb53687ed6 100644
> --- a/configs/j721e_beagleboneai64_a72_defconfig
> +++ b/configs/j721e_beagleboneai64_a72_defconfig
> @@ -97,7 +97,7 @@ CONFIG_DMA_CHANNELS=y
>  CONFIG_TI_K3_NAVSS_UDMA=y
>  CONFIG_USB_FUNCTION_FASTBOOT=y
>  CONFIG_FASTBOOT_BUF_ADDR=0x82000000
> -CONFIG_FASTBOOT_BUF_SIZE=0x2F000000
> +CONFIG_FASTBOOT_BUF_SIZE=0x1c800000

What you think to move CONFIG_FASTBOOT_BUF_SIZE to upper memory, similar
to  configs/j722s_evm_a53_defconfig


>  CONFIG_FASTBOOT_FLASH=y
>  CONFIG_FASTBOOT_FLASH_MMC_DEV=0
>  CONFIG_FASTBOOT_CMD_OEM_FORMAT=y
> diff --git a/configs/j721e_evm_a72_defconfig b/configs/j721e_evm_a72_defconfig
> index ed94fff0885..dac1c5ec82f 100644
> --- a/configs/j721e_evm_a72_defconfig
> +++ b/configs/j721e_evm_a72_defconfig
> @@ -104,7 +104,7 @@ CONFIG_DMA_CHANNELS=y
>  CONFIG_TI_K3_NAVSS_UDMA=y
>  CONFIG_USB_FUNCTION_FASTBOOT=y
>  CONFIG_FASTBOOT_BUF_ADDR=0x82000000
> -CONFIG_FASTBOOT_BUF_SIZE=0x2F000000
> +CONFIG_FASTBOOT_BUF_SIZE=0x1c800000
>  CONFIG_FASTBOOT_FLASH=y
>  CONFIG_FASTBOOT_FLASH_MMC_DEV=0
>  CONFIG_FASTBOOT_CMD_OEM_FORMAT=y