i.MX91 EVK
Overview
The i.MX 91 Evaluation Kit (MCIMX91-EVK board) is a platform designed to display the most commonly used features of the i.MX 91 applications processor. The MCIMX91-EVK board is an entry-level development board with a small and low-cost package. The board can be used by developers to get familiar with the processor before investing a large amount of resources in more specific designs.
The i.MX 91 applications processor features an Arm Cortex-A55 core that can operate at speeds of up to 1.4 GHz.
Board features:
RAM: 2GB LPDDR4
Storage:
SanDisk 16GB eMMC5.1
microSD Socket
Wireless:
Murata Type-2EL (SDIO+UART+SPI) module. It is based on NXP IW612 SoC, which supports dual-band (2.4 GHz /5 GHz) 1x1 Wi-Fi 6, Bluetooth 5.2, and 802.15.4
USB:
Two USB 2.0 Type C connectors
Ethernet:
ENET: 10/100/1000 Mbit/s RGMII Ethernet connected with external PHY RTL8211
ENET_QoS: 10/100/1000 Mbit/s RGMII Ethernet supporting TSN connected with external PHY RTL8211
PCIe:
One M.2/NGFF Key E mini card 75-pin connector
Connectors:
40-Pin Dual Row Header
LEDs:
1x Power status LED
2x UART LED
Debug:
JTAG 20-pin connector
MicroUSB for UART debug
Supported Features
The imx91_evk board supports the hardware features listed below.
- on-chip / on-board
- Feature integrated in the SoC / present on the board.
- 2 / 2
-
Number of instances that are enabled / disabled.
Click on the label to see the first instance of this feature in the board/SoC DTS files. -
vnd,foo -
Compatible string for the Devicetree binding matching the feature.
Click on the link to view the binding documentation.
Devices
System Clock
This board configuration uses a system clock frequency of 24 MHz. Cortex-A55 Core runs up to 1.4 GHz.
Serial Port
This board configuration uses a single serial communication channel with the CPU’s UART1 for A55 core.
Programming and Debugging
The imx91_evk board supports the runners and associated west commands listed below.
| flash | debug |
|---|
There are multiple methods to program and debug Zephyr
Option 1. Boot Zephyr by Using JLink Runner
The default runner for the board is JLink, connect the EVK board’s JTAG connector to the host computer using a J-Link debugger, power up the board and stop the board at U-Boot command line.
Then use “west flash” or “west debug” command to load the zephyr.bin image from the host computer and start the Zephyr application on A55 core0.
Flash and Run
Here is an example for the Hello World application.
# From the root of the zephyr repository
west build -b imx91_evk/mimx9131 samples/hello_world
west flash
Then the following log could be found on UART1 console:
*** Booting Zephyr OS build v4.1.0-3063-g2c7ef313ac38 ***
Hello World! imx91_evk/mimx9131
Debug
Here is an example for the Hello World application.
# From the root of the zephyr repository
west build -b imx91_evk/mimx9131 samples/hello_world
west debug
Option 2. Boot Zephyr by Using U-Boot Command
U-Boot “go” command is used to load and kick Zephyr to Cortex-A55 Core.
Copy the compiled zephyr.bin to the first FAT partition of the SD card and
plug the SD card into the board. Power it up and stop the u-boot execution at
prompt.
Use U-Boot to load and kick zephyr.bin to Cortex-A55 Core:
fatload mmc 1:1 0x80000000 zephyr.bin; dcache flush; icache flush; go 0x80000000
Use this configuration to run basic Zephyr applications and kernel tests, for example, with the Basic Synchronization sample:
# From the root of the zephyr repository
west build -b imx91_evk/mimx9131 samples/synchronization
This will build an image with the synchronization sample app, boot it and display the following console output:
*** Booting Zephyr OS build v4.0.0-3277-g69f43115c9a8 ***
thread_a: Hello World from cpu 0 on imx91_evk!
thread_b: Hello World from cpu 0 on imx91_evk!
thread_a: Hello World from cpu 0 on imx91_evk!
thread_b: Hello World from cpu 0 on imx91_evk!
Option 3. Boot Zephyr by Using SPSDK Runner
SPSDK runner leverages SPSDK tools (https://spsdk.readthedocs.io), it builds an
bootable flash image flash.bin which includes all necessary firmware components.
Using west flash command will download the boot image flash.bin to DDR memory, SD card
or eMMC flash. By using flash.bin, as no U-Boot image is available, so TF-A will boot
up Zephyr on the Cortex-A55 Core directly.
In order to use SPSDK runner, it requires fetching binary blobs, which can be achieved by running the following command:
west blobs fetch hal_nxp
Note
It is recommended running the command above after west update.
SPSDK runner is enabled by configure item CONFIG_BOARD_NXP_SPSDK_IMAGE, currently
it is not enabled by default for IMX91 EVK board, so use this configuration to enable
it, for example, with the Basic Synchronization sample:
# From the root of the zephyr repository
west build -b imx91_evk/mimx9131 samples/synchronization -- -DCONFIG_BOARD_NXP_SPSDK_IMAGE=y
If CONFIG_BOARD_NXP_SPSDK_IMAGE is available and enabled for the board variant,
flash.bin will be built automatically. The programming could be through below commands.
Before that, onboard switch SW1301[3:0] should be configured to 0b0011 for USB download mode
to boot, and USB1 and DBG ports should be connected to Linux host PC. There are 2 serial ports
enumerated (115200 8n1), the first port will be used for Cortex-A55 Zephyr’s Console.
(The flasher is spsdk which already installed via scripts/requirements.txt.
On Linux host, USB device permission should be configured per Installation Guide
of https://spsdk.readthedocs.io)
# load and run without programming. for next flashing, need to reset the board firstly
$ west flash -r spsdk
# program to SD card, then set SW1301[3:0]=0b0010 to reboot from SD
$ west flash -r spsdk --bootdevice sd
# program to emmc card, then set SW1301[3:0]=0b0000 to reboot from EMMC
$ west flash -r spsdk --bootdevice=emmc
Then the Zephyr log will be displayed in the first serial port’s console.