From mboxrd@z Thu Jan 1 00:00:00 1970 From: David Lechner Subject: [PATCH v2 1/2] ARM: dts: da850-lego-ev3: Add node for reboot modes Date: Thu, 11 Jan 2018 20:29:50 -0600 Message-ID: <1515724191-30499-2-git-send-email-david@lechnology.com> References: <1515724191-30499-1-git-send-email-david@lechnology.com> Return-path: In-Reply-To: <1515724191-30499-1-git-send-email-david-nq/r/kbU++upp/zk7JDF2g@public.gmane.org> Sender: devicetree-owner-u79uwXL29TY76Z2rM5mHXA@public.gmane.org To: linux-arm-kernel-IAPFreCvJWM7uuMidbF8XUB+6BGkLq7r@public.gmane.org Cc: David Lechner , Sekhar Nori , Kevin Hilman , Rob Herring , Mark Rutland , devicetree-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, linux-kernel-u79uwXL29TY76Z2rM5mHXA@public.gmane.org List-Id: devicetree@vger.kernel.org This adds a new node for reboot modes on LEGO MINDSTORMS EV3. The EV3's bootloader looks for a magic number in the ARM local RAM and if found, it will boot into a special firmware update mode where the flash memory can be written via USB. This has been testing working using the command: # systemctl reboot loader Signed-off-by: David Lechner --- arch/arm/boot/dts/da850-lego-ev3.dts | 17 +++++++++++++++++ 1 file changed, 17 insertions(+) diff --git a/arch/arm/boot/dts/da850-lego-ev3.dts b/arch/arm/boot/dts/da850-lego-ev3.dts index 81942ae..2e85080 100644 --- a/arch/arm/boot/dts/da850-lego-ev3.dts +++ b/arch/arm/boot/dts/da850-lego-ev3.dts @@ -184,6 +184,23 @@ io-channel-names = "voltage", "current"; rechargeable-gpios = <&gpio 136 GPIO_ACTIVE_LOW>; }; + + /* ARM local RAM */ + memory@ffff0000 { + compatible = "syscon", "simple-mfd"; + reg = <0xffff0000 0x2000>; /* 8k */ + + /* + * The I2C bootloader looks for this magic value to either + * boot normally or boot into a firmware update mode. + */ + reboot-mode { + compatible = "syscon-reboot-mode"; + offset = <0x1ffc>; + mode-normal = <0x00000000>; + mode-loader = <0x5555aaaa>; + }; + }; }; &pmx_core { -- 2.7.4 -- To unsubscribe from this list: send the line "unsubscribe devicetree" in the body of a message to majordomo-u79uwXL29TY76Z2rM5mHXA@public.gmane.org More majordomo info at http://vger.kernel.org/majordomo-info.html