BPI-R4 Pro 8X: boots only after Type-C Console cable is connected

Hello everyone,

I am reaching out for help with a serious issue on my Banana Pi BPI-R4 Pro 8X board, which I received just 5 days ago.

The core problem: The board does not boot on its own with any firmware. I have flashed firmware to both eMMC and SD card — the result is always the same. Without connecting the console cable (Type-C UART), the boot process does not proceed. The board hangs at the preinit stage indefinitely and only continues booting after the cable is plugged in.

The log confirms the anomaly:

[    6.653852] usb 1-1: new high-speed USB device number 2 using xhci-mtk
[    6.705460] mtk_soc_eth 15100000.ethernet wan: renamed from eth1
[    6.711994] ttyS ttyS0: 71 input overrun(s)
[    6.728938] mtk_soc_eth 15100000.ethernet eth0: configuring for fixed/internal link mode
[    6.738179] mtk_soc_eth 15100000.ethernet eth0: Link is Up - 10Gbps/Full - flow control rx/tx
[    6.807716] hub 1-1:1.0: USB hub found
[    6.813165] hub 1-1:1.0: 4 ports detected
[    6.941347] usb 2-1: new SuperSpeed USB device number 2 using xhci-mtk
[    6.993690] hub 2-1:1.0: USB hub found
[    6.998266] hub 2-1:1.0: 4 ports detected
[   16.474038] platform gpio-leds: deferred probe pending: leds-gpio: Failed to get GPIO '/gpio-leds/sys-led-red'
[   16.485026] ttyS ttyS0: 9 input overrun(s)
[23836.360733] mount_root: loading kmods from internal overlay
[23836.382122] kmodloader: loading kernel modules from //etc/modules-boot.d/*
[23836.392354] kmodloader: done loading kernel modules from //etc/modules-boot.d/*
[23836.888496] block: attempting to load /tmp/overlay/upper/etc/config/fstab
[23836.897530] block: unable to load configuration (fstab: Entry not found)
[23836.904269] block: attempting to load /tmp/overlay/etc/config/fstab
[23836.910577] block: unable to load configuration (fstab: Entry not found)
[23836.917316] block: attempting to load /etc/config/fstab
[23836.927386] block: unable to load configuration (fstab: Entry not found)
[23836.934160] block: no usable configuration

The time gap between [16.48] and [23836.36] is nearly 6.6 hours. The system remains stuck until the console cable is connected.

Hardware configuration:

  • Wi-Fi module: MediaTek MT7915E (Mini PCIe)
  • Storage: NVMe SSD (used as data storage)

Additional symptoms: The fan starts running immediately after power-on. Its speed can be changed using echo 50 > /sys/class/hwmon/hwmon2/pwm1, but echo 0 > /sys/class/hwmon/hwmon2/pwm1 does not turn it off.

What I have already tried: Multiple firmware versions (official Banana Pi builds and frank-w builds) — no change. Booting from both eMMC and SD card — same behavior. Currently running firmware: Эта версия браузера устарела, папку нельзя открыть

Kernel version: 6.18.34 Firmware version: OpenWrt SNAPSHOT r34789+5-1ba7b38cfc

My question: Does this look like a hardware failure? Are there any known issues with the BPI-R4 Pro related to power delivery or clock generation? I would appreciate any ideas or suggestions.

I would suspect a problem with the serial driver. You could disable the serial console by a kernel parameter, and then you would have no console output but presumably also not this problem.

You could pass something like console=tty0 to the kernel (provided this console type is enabled in the kernel config) to not send any output to the serial console, removing any other console= parameter.

The kernel parameters are probably passed by u-boot. If so you would have to modify the u-boot default boot command to change this. Sometimes this is saved in u-boot environment, sometimes it requires rebuilding u-boot.

Also passing different parameters for the serial console (eg. flow control related) might work.

1 Like
MT7988> printenv bootargs
bootargs=console=ttyS0,115200n1 pci=pcie_bus_perf root=/dev/fit0 rootwait
MT7988> setenv bootargs console=tty0
MT7988> saveenv
Saving Environment to MMC... Writing to redundant MMC(0)... OK
MT7988> boot

I ran those commands and the console disconnected. I saved that to memory. After a few reboots, the freezing is gone. Thanks! The console did disconnect, but I can always turn it back on if needed.

What can I do about the fan? It won’t turn off. The speed can be adjusted from max 255 down to min 1, but at 0 it keeps running.