secubox-deb/docs/wiki/MOCHAbin-Kernel.md

MOCHAbin Kernel — LED & Hardware Support

SecuBox kernel configuration for GlobalScale MOCHAbin (Armada 7040)

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Hardware Overview

Component	Chip	Kernel Driver	Address
LED Controller	IS31FL3199	leds-is31fl319x	I2C-1 0x64
Network PPv2.2	Marvell PPv2	mvpp2	Built-in
I2C Bus	MV64XXX	i2c-mv64xxx	CP0
eMMC	Xenon	mmc_sdhci_xenon	CP0
SFP Cage	PHY/SFP	sfp + phylink	eth2

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Build Strategy

Why Debian Base + SecuBox Fragment?

Previous custom minimal configs caused kernel panics due to missing network drivers (MVPP2, MVNETA). The current approach:

1. Start with Debian arm64 kernel config — includes all working drivers
2. Merge SecuBox fragment — enables LED drivers as built-in (=y)
3. Apply DTS patch — fixes GPIO polarity for LED shutdown pin

# Build workflow
cd linux-6.12.85
cp config-6.12.85-debian-base .config
./scripts/kconfig/merge_config.sh -m .config config-6.12.85-secubox-led-v2.fragment
make ARCH=arm64 CROSS_COMPILE=aarch64-linux-gnu- olddefconfig
make ARCH=arm64 CROSS_COMPILE=aarch64-linux-gnu- -j$(nproc) Image modules dtbs

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Config Files

Debian Base Config

Location: board/mochabin/kernel/config-6.12.85-debian-base

Extracted from working Debian MOCHAbin system with:

zcat /proc/config.gz > config-6.12.85-debian-base

Key working drivers (already =y or =m):

• CONFIG_MVPP2=m — Marvell PPv2.2 Ethernet
• CONFIG_MVNETA=m — Marvell NETA Ethernet
• CONFIG_MVMDIO=m — Marvell MDIO bus
• CONFIG_MARVELL_PHY=m — PHY drivers
• CONFIG_I2C_MV64XXX=m — I2C controller

SecuBox LED Fragment

Location: board/mochabin/kernel/config-6.12.85-secubox-led-v2.fragment

# LED Driver (IS31FL3199 on MOCHAbin)
CONFIG_LEDS_IS31FL319X=y
CONFIG_LEDS_IS31FL32XX=y
CONFIG_LEDS_CLASS=y
CONFIG_LEDS_CLASS_MULTICOLOR=y

# LED Triggers
CONFIG_LEDS_TRIGGERS=y
CONFIG_LEDS_TRIGGER_TIMER=y
CONFIG_LEDS_TRIGGER_HEARTBEAT=y
CONFIG_LEDS_TRIGGER_CPU=y
CONFIG_LEDS_TRIGGER_DEFAULT_ON=y
CONFIG_LEDS_TRIGGER_NETDEV=y

# I2C (for LED controller)
CONFIG_I2C_MV64XXX=y
CONFIG_I2C_CHARDEV=y
CONFIG_REGMAP_I2C=y

# Network (MOCHAbin PPv2.2)
CONFIG_MVPP2=y
CONFIG_MVMDIO=y
CONFIG_MVNETA=y
CONFIG_PHYLINK=y
CONFIG_FIXED_PHY=y
CONFIG_MARVELL_PHY=y
CONFIG_SFP=y

# MMC/eMMC (Xenon controller)
CONFIG_MMC_SDHCI_XENON=y

# GPIO (for LED shutdown pin)
CONFIG_GPIO_MVEBU=y
CONFIG_PINCTRL_MVEBU=y
CONFIG_PINCTRL_ARMADA_CP110=y
CONFIG_PINCTRL_ARMADA_AP806=y

# Debug: /proc/config.gz
CONFIG_IKCONFIG=y
CONFIG_IKCONFIG_PROC=y

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DTS Patch — GPIO Polarity Fix

The Problem

The IS31FL3199 has a SDB (shutdown bar) pin that must be driven HIGH to enable the chip. The upstream kernel DTS incorrectly uses GPIO_ACTIVE_LOW, keeping the LED controller in permanent shutdown.

The Fix

Location: board/mochabin/patches/0001-fix-is31fl3199-led-gpio-polarity.patch

--- a/arch/arm64/boot/dts/marvell/armada-7040-mochabin.dts
+++ b/arch/arm64/boot/dts/marvell/armada-7040-mochabin.dts
@@ -236,7 +236,7 @@
    #size-cells = <0>;
    pinctrl-names = "default";
    pinctrl-0 = <&is31_sdb_pins>;
-   shutdown-gpios = <&cp0_gpio1 30 GPIO_ACTIVE_LOW>;
+   shutdown-gpios = <&cp0_gpio1 30 GPIO_ACTIVE_HIGH>;
    reg = <0x64>;

Upstream Status

This fix should be submitted to linux-arm-kernel@lists.infradead.org for inclusion. Similar devices in the kernel (cn9130-cf-base.dts, cn9132-clearfog.dts) already use GPIO_ACTIVE_HIGH.

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LED Hardware on MOCHAbin

I2C Detection

$ i2cdetect -y 1
     0  1  2  3  4  5  6  7  8  9  a  b  c  d  e  f
00:                         -- -- -- -- -- -- -- --
10: -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- --
20: -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- --
30: -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- --
40: -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- --
50: -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- --
60: -- -- -- -- 64 -- -- -- -- -- -- -- -- -- -- --
70: -- -- -- -- -- -- -- --

LED Mapping

LED	Color	DTS Name	Usage
led1	Red	led@1	Activity
led2	Green	led@2	System
led3	Blue	led@3	Network
led4-9	RGB	led@4-9	Status

LED Control

# List available LEDs
ls /sys/class/leds/

# Set LED trigger
echo heartbeat > /sys/class/leds/led1_red/trigger

# Manual brightness
echo 255 > /sys/class/leds/led2_green/brightness

# Network activity trigger
echo netdev > /sys/class/leds/led3_blue/trigger
echo eth0 > /sys/class/leds/led3_blue/device_name
echo "rx tx" > /sys/class/leds/led3_blue/mode

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LOCALVERSION Branding

The kernel is built with:

LOCALVERSION=-secubox-cybermind

This produces a kernel version string like:

Linux secubox 6.12.85-secubox-cybermind #1 SMP PREEMPT Thu May 8 2026 aarch64

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Build Script

Location: kernel-build/rebuild-with-leds.sh

The script:

1. Copies Debian base config
2. Merges SecuBox LED fragment
3. Applies GPIO polarity DTS patch
4. Verifies critical options are built-in
5. Builds Image + DTB + modules
6. Creates .deb packages

./kernel-build/rebuild-with-leds.sh

Output files:

• arch/arm64/boot/Image
• arch/arm64/boot/dts/marvell/armada-7040-mochabin.dtb
• linux-image-6.12.85-secubox-cybermind_*.deb
• linux-headers-6.12.85-secubox-cybermind_*.deb

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Troubleshooting

LED Not Working

1. Check I2C detection: i2cdetect -y 1 should show 64
2. Check dmesg: dmesg | grep -i is31fl
3. Verify config: zcat /proc/config.gz | grep IS31FL
4. Check GPIO: gpioinfo | grep sdb

Network Panic

If network fails with panic:

• Verify CONFIG_MVPP2=y (must be built-in, not module)
• Verify CONFIG_PHYLINK=y
• Check DTB has correct MAC addresses

Build Failures

# Missing cross-compiler
apt install gcc-aarch64-linux-gnu

# Missing dependencies
apt install build-essential libssl-dev bc bison flex libelf-dev

# Verify ARCH is set
export ARCH=arm64
export CROSS_COMPILE=aarch64-linux-gnu-

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References

• IS31FL3199 Datasheet
• Marvell PPv2 Driver
• MOCHAbin Wiki
• Linux LED Class

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CyberMind — SecuBox-Deb · docs/wiki/MOCHAbin-Kernel.md