[PATCH 0/2] Add reboot modes for LEGO MINDSTORMS EV3

[PATCH 0/2] Add reboot modes for LEGO MINDSTORMS EV3

[David Lechner]

This series adds a new device tree node to declare a special memory
address that is used by the I2C bootloader on LEGO MINDSTORMS EV3
to boot into a special firmware update mode and enables the required
module to use it.

David Lechner (2):
  ARM: dts: da850-lego-ev3: Add node for reboot modes
  ARM: davinci_all_defconfig: enable SYSCON_REBOOT_MODE

 arch/arm/boot/dts/da850-lego-ev3.dts   | 17 +++++++++++++++++
 arch/arm/configs/davinci_all_defconfig |  1 +
 2 files changed, 18 insertions(+)

-- 
2.7.4

[PATCH 1/2] ARM: dts: da850-lego-ev3: Add node for reboot modes

[David Lechner]

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 <david@lechnology.com>
---
 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 e4bbf48..1cb2ff1 100644
--- a/arch/arm/boot/dts/da850-lego-ev3.dts
+++ b/arch/arm/boot/dts/da850-lego-ev3.dts
@@ -212,6 +212,23 @@
 		compatible = "gpio-backlight";
 		gpios = <&gpio 44 GPIO_ACTIVE_HIGH>;
 	};
+
+	/* ARM local RAM */
+	memory at 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>;
+		};
+	};
 };
 
 &cpu {
-- 
2.7.4

[PATCH 1/2] ARM: dts: da850-lego-ev3: Add node for reboot modes

[David Lechner]

On 01/11/2018 08:21 PM, David Lechner wrote:
> 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 <david@lechnology.com>
> ---

Doh. I forgot to rebase, so this won't apply cleanly. V2 coming right up.

[PATCH 2/2] ARM: davinci_all_defconfig: enable SYSCON_REBOOT_MODE

[David Lechner]

This enables SYSCON_REBOOT_MODE as a module. This is used by LEGO
MINDSTORMS EV3 to reboot into a special firmware update mode.

Signed-off-by: David Lechner <david@lechnology.com>
---
 arch/arm/configs/davinci_all_defconfig | 1 +
 1 file changed, 1 insertion(+)

diff --git a/arch/arm/configs/davinci_all_defconfig b/arch/arm/configs/davinci_all_defconfig
index 282b3e4..62f853f 100644
--- a/arch/arm/configs/davinci_all_defconfig
+++ b/arch/arm/configs/davinci_all_defconfig
@@ -135,6 +135,7 @@ CONFIG_GPIO_PCA953X=y
 CONFIG_GPIO_PCA953X_IRQ=y
 CONFIG_POWER_RESET=y
 CONFIG_POWER_RESET_GPIO=y
+CONFIG_SYSCON_REBOOT_MODE=m
 CONFIG_BATTERY_LEGO_EV3=m
 CONFIG_WATCHDOG=y
 CONFIG_DAVINCI_WATCHDOG=m
-- 
2.7.4