MBa8MP-RAS314 - YOCTO Linux BSP documentation

REV.020x SoM without variant data in EEPROM (prototypes)

• With the default U-Boot configuration the boot flow is interrupted in SPL and waits for input of the assembled RAM size (1, 2, 4, 8).
• Use fixed 2GB U-Boot configuration. This is built by default UBOOT_CONFIG entries sd-2gb and uuu-2gb Note: the generated wic-File uses the U-Boot multi RAM config

FlexSPI: the configured clock exceeds the limit given in datasheet

When using without DQS internal clock, delay limits the maximum usable speed to 66MHz. The interface is configured with a limit of 80MHz.

MIPI CSI

• driver stack is not completely v4l2-compliance test proof. The IOCTLS for format / resolution enumeration and query can return invalid / wrong values depending of the internal state of the driver stack. Please follow given examples for a working setup.
• IMX327: bayer support with 12 Bit does not work at the moment, only 10 Bit with 1280x720 is tested with gstreamer
• IMX327: when configuring to SRGGB12 reboot may be needed to get a working capture again
• OV9281: gstreamer does not support Y10 format

Ethernet

• Possible communication error to PHY attached to FEC, reboot required to fix
• ETH1 looses manual assigned IP after suspend/resume. Default systemd network configuration uses DHCP with fallback. Has to be adjusted if needed.

A reset using button S7 will not reset the SD card properly. Especially if the SD card is operating on 1.8V it will be non-functional after reset. Use button S8 instead.

PCIe

• Some WiFi modules might not be supported
• Suspend to RAM not supported. Disable PCIe RC node in device tree

  &pcie {
  status = "disabled";
  };

Audio

• Suspend to RAM does not work reliably. Disable sound node in device tree

  sound {
  compatible = "fsl,imx-audio-tlv320aic32x4";
  [...]
  status = "disabled";
  };

USB Host

• USB Superspeed U3 powersave mode is broken
• U-Boot: some USB stick types are not working correctly in U-Boot. After usb reset they may fail to enumerate correctly or causing a system reset during enumeration with errors like:

  WARN halted endpoint, queueing URB anyway.
  Unexpected XHCI event TRB, skipping... (fbf120f0 00000000 13000000 03008401)
  BUG at drivers/usb/host/xhci-ring.c:496/abort_td()!
  BUG!
  �esetting ...

USB Bluetooth:

• Some adapters cause the following error during bootup
  Bluetooth: hci0: unexpected event for opcode 0xfc2f
  According to https://lkml.org/lkml/2019/6/6/868 this can be ignored

UBI / UBIFS images are enabled by default when using DISTRO=spaetzle[-nxp]. The generated rootfs size must not exceed the size defined by UBI_LEB_SIZE and UBI_MAX_LEB_COUNT on machine level.

Kernel based on linux-imx / linux-fslc: Review indicated that, by default, device tree reserves memory for NPU in an area which is only available on 4GiB DDR RAM config. Upstream kernel is not affected.

Kernel based on linux-tq / linux-rt-tq

• Suspend & resume not supported (yet)

MBa8MP-RAS314

• no support for vendor kernel and BSP

When using HDMI the default audio device changes to HDMI output. For using I2S audio codec aplay requires the parameter -Dsysdefault:CARD=tqmtlv320aic32

The HDMI audio device has to be selected explicitely by passing -Dsysdefault:CARD=audiohdmi to aplay & friends