The same register we use for the reboot mode communication between Linux and barebox is also sampled by the bootrom. If the lowest 16 bits of it are 0x00FF, the bootrom will enter DFU mode. Add the appropriate reboot-mode, but with a barebox, prefix, so Linux doesn't automatically provide it to userspace along with the existing loader and recovery modes. Signed-off-by: Ahmad Fatoum <a.fatoum@xxxxxxxxxxxxxx> --- arch/arm/dts/stm32mp151.dtsi | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) diff --git a/arch/arm/dts/stm32mp151.dtsi b/arch/arm/dts/stm32mp151.dtsi index ed7cf6192bea..ac6536a556a9 100644 --- a/arch/arm/dts/stm32mp151.dtsi +++ b/arch/arm/dts/stm32mp151.dtsi @@ -41,9 +41,10 @@ reboot_mode_tamp: reboot-mode { compatible = "syscon-reboot-mode"; offset = <0x150>; /* reg20 */ - mask = <0xff>; + mask = <0xffff>; mode-normal = <0>; mode-loader = <0xBB>; mode-recovery = <0xBC>; + barebox,mode-serial = <0xFF>; }; }; -- 2.30.2