MIMX8MQ EVK
Overview
i.MX8MQ EVK board is based on NXP i.MX8MQ applications processor, composed of a quad Cortex®-A53 cluster and a single Cortex®-M4 core. Zephyr OS is ported to run on the Cortex®-M4 core.
Board features:
RAM: 3GB LPDDR4
Storage:
16GB eMMC5.0
32MB QSPI NOR
microSD Socket
Wireless:
WiFi: 2.4/5GHz IEEE 802.11 a/b/g/n/ac
Bluetooth: v4.1
USB:
OTG - 1x type C
HOST - 1x type A
Ethernet
PCI-E M.2
LEDs:
1x Power status LED
1x UART LED
Debug
JTAG 10-pin connector
MicroUSB for UART debug, two COM ports for A53 and M4
More information about the board can be found at the NXP website.
Supported Features
The Zephyr mimx8mq_evk board configuration supports the following hardware features:
Interface |
Controller |
Driver/Component |
---|---|---|
NVIC |
on-chip |
nested vector interrupt controller |
SYSTICK |
on-chip |
systick |
CLOCK |
on-chip |
clock_control |
PINMUX |
on-chip |
pinmux |
UART |
on-chip |
serial port-polling; serial port-interrupt |
The default configuration can be found in the defconfig file: boards/nxp/imx8mq_evk/imx8mq_evk_mimx8mq6_m4_defconfig.
Other hardware features are not currently supported by the port.
Connections and IOs
MIMX8MQ EVK board was tested with the following pinmux controller configuration.
Board Name |
SoC Name |
Usage |
---|---|---|
UART2 RXD |
UART2_TXD |
UART Console |
UART2 TXD |
UART2_RXD |
UART Console |
System Clock
The M4 Core is configured to run at a 266 MHz clock speed.
Serial Port
The i.MX8MQ SoC has four UARTs. UART_2 is configured for the console and the remaining are not used/tested.
Programming and Debugging
The MIMX8MQ EVK board doesn’t have QSPI flash for the M4 and it needs to be started by the A53 core. The A53 core is responsible to load the M4 binary application into the RAM, put the M4 in reset, set the M4 Program Counter and Stack Pointer, and get the M4 out of reset. The A53 can perform these steps at bootloader level or after the Linux system has booted.
The M4 can use up to 3 different RAMs. These are the memory mapping for A53 and M4:
Region |
Cortex-A53 |
Cortex-M4 (System Bus) |
Cortex-M4 (Code Bus) |
Size |
---|---|---|---|---|
OCRAM |
0x00900000-0x0091FFFF |
0x20200000-0x2021FFFF |
0x00900000-0x0091FFFF |
128KB |
TCMU |
0x00800000-0x0081FFFF |
0x20000000-0x2001FFFF |
128KB |
|
TCML |
0x007E0000-0x007FFFFF |
0x1FFE0000-0x1FFFFFFF |
128KB |
|
OCRAM_S |
0x00180000-0x00187FFF |
0x20180000-0x20187FFF |
0x00180000-0x00187FFF |
32KB |
For more information about memory mapping see the i.MX 8M Applications Processor Reference Manual (section 2.1.2 and 2.1.3)
At compilation time you have to choose which RAM will be used. This configuration is done in the file boards/nxp/imx8mq_evk/imx8mq_evk_mimx8mq6_m4.dts with “zephyr,flash” (when CONFIG_XIP=y) and “zephyr,sram” properties. The available configurations are:
"zephyr,flash"
- &tcml_code
- &ocram_code
- &ocram_s_code
"zephyr,sram"
- &tcmu_sys
- &ocram_sys
- &ocram_s_sys
Load and run Zephyr on M4 from A53 using u-boot.
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.
Load the M4 binary onto the desired memory and start its execution using:
fatload mmc 0:1 0x40480000 zephyr.bin
cp.b 0x40480000 0x7e0000 0x8000
bootaux 0x7e0000
This procedure requires screen
and lrzsz
to be installed.
Start screen
, power up the board, and stop the u-boot execution at prompt:
screen <tty-device> 115200
Start loadx
with offset 7e0000
:
loadx 7e0000 115200
Send the compiled zephyr.bin
with sx
by pressing Ctrl-a followed by :
and write:
exec !! sx </full/path/to/zephyr.bin>
Start execution:
bootaux 0x7e0000
Debugging
MIMX8MQ EVK board can be debugged by connecting an external JLink JTAG debugger to the J401 debug connector and to the PC. Then the application can be debugged using the usual way.
Here is an example for the Hello World application.
# From the root of the zephyr repository
west build -b imx8mq_evk/mimx8mq6/m4 samples/hello_world
west debug
Open a serial terminal, step through the application in your debugger, and you should see the following message in the terminal:
***** Booting Zephyr OS build zephyr-v2.6.99-30942-g6ee70bd22058 *****
Hello World! imx8mq_evk