[U-Boot] [PATCH] rpi: Do not use dtb loaded by firmware

[Alexander Graf]

On 11/08/2018 09:36 AM, Jun Nie wrote:
> Do not use dtb loaded by firmware if fit image signature is enabled.
> So that u-boot.dtb can be used. The u-boot.dtb contains the pulibc key
> that is to verify Linux kernel FIT image blob.
>
> The u-boot.dtb can be loaded by Arm Trusted Firmware(ATF) together
> with u-boot.bin to make sure the key is protected by ATF.

I don't think I fully understand what you're trying to do here. If ATF 
loads U-Boot as well as the DT, ATF can pass the DT to U-Boot which then 
ends up as $fdtaddr. If you enable CONFIG_OF_BOARD, it even becomes the 
input DT for U-Boot.

Hiding the fdtfile variable name doesn't sound like it solves anything 
to me?


Alex

>
> Signed-off-by: Jun Nie <jun.nie at linaro.org>
> ---
>   board/raspberrypi/rpi/rpi.c | 6 ++++++
>   1 file changed, 6 insertions(+)
>
> diff --git a/board/raspberrypi/rpi/rpi.c b/board/raspberrypi/rpi/rpi.c
> index 649127c..f7041e3 100644
> --- a/board/raspberrypi/rpi/rpi.c
> +++ b/board/raspberrypi/rpi/rpi.c
> @@ -283,6 +283,7 @@ int dram_init(void)
>   	return 0;
>   }
>   
> +#ifndef CONFIG_FIT_SIGNATURE
>   static void set_fdtfile(void)
>   {
>   	const char *fdtfile;
> @@ -318,6 +319,7 @@ unsigned long board_get_usable_ram_top(unsigned long total_size)
>   		return gd->ram_top;
>   	return fw_dtb_pointer & ~0xffff;
>   }
> +#endif
>   
>   static void set_usbethaddr(void)
>   {
> @@ -390,8 +392,10 @@ static void set_serial_number(void)
>   
>   int misc_init_r(void)
>   {
> +#ifndef CONFIG_FIT_SIGNATURE
>   	set_fdt_addr();
>   	set_fdtfile();
> +#endif
>   	set_usbethaddr();
>   #ifdef CONFIG_ENV_VARS_UBOOT_RUNTIME_CONFIG
>   	set_board_info();
> @@ -467,6 +471,7 @@ int board_init(void)
>   	return bcm2835_power_on_module(BCM2835_MBOX_POWER_DEVID_USB_HCD);
>   }
>   
> +#ifndef CONFIG_FIT_SIGNATURE
>   /*
>    * If the firmware passed a device tree use it for U-Boot.
>    */
> @@ -476,6 +481,7 @@ void *board_fdt_blob_setup(void)
>   		return NULL;
>   	return (void *)fw_dtb_pointer;
>   }
> +#endif
>   
>   int ft_board_setup(void *blob, bd_t *bd)
>   {