i.MX6 SoloX M4 boot first

[jasonyuan_mdt]

I have checked the document, it is said that SoloX A9 is always boot first, due to A9 is Linux OS, the boot time is too slow. I want to boot the M4 first, and in 500ms, how can I do that?

[jasonyuan_mdt]

Carlos, another question of the M4.

I need M4 boot up first and then congfig camera and LCD screen via "AXI and AHB Switch Fabric".

But distributor told me the M4 may not access and control camera and LCD, so I am confused.

Can you help me to clearify this question?

[jasonyuan_mdt]

I understand.

Can you recommend a chip could both run Linux and RTOS, RTOS could quick boot up and handle peripherals(I need to quick turn on the screen)?

for example, i.MX7 for something else?

[mtx512]

Some options to consider are:

1. Initialize the LCD (and other peripherals) in uboot after/before you launch the M4 to reduce initialization time.

2. Depending on your LCD and use case you can directly interface it to the M4 (see this example).

3. Strip down kernel to minimal configuration to decrease boot time.

[jasonyuan_mdt]

if I use i.MX 7Solo/ 7ULP, which contains A7 and M4, could M4 handle peripherals?

[mtx512]

For i.MX7 (very similar to i.MX6SX) the default peripheral support on the M4 side is only GPIO, I2C, EPIT,  WDOG. UART, ADC and CAN. If you planning to use other peripherals then you would need to implement your own solution if its technically feasible. 

[Carlos_Musich]

Hi Jason,

In hardware the A9 boots before M4 and it is responsible to configure clocks and start M4, therefore it is not possible to do it the other way, however it is not necessary to start Linux, you can start M4 form U-boot. There are good examples and documentation using FreeRTOS which you can downlaod at

www.nxp.com/imx6SX > Software & Tools tab > FreeRTOS™ BSP 1.0.1 for the i.MX 6SoloX ARM® Cortex®-M4 core

Inside the FreeRTOS BSP installation folder you will find documentation including the following files, you may take a look to the chapters indicated below..

• Getting_Started_with_FreeRTOS_BSP_for_i.MX_7Dual.pdf / Getting_Started_with_FreeRTOS_BSP_for_i.MX_6SoloX.pdf

         Chapter 6 Running Application with U-Boot

Regards,
Carlos

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[jasonyuan_mdt]

Hi Carlos,

Can I start M4 form U-boot first, after that, start A9 Linux environment?

thanks.

[Carlos_Musich]

Yes, in uboot you can start M4 and Linux is not running. Then in uboot you can execute command 'boot' and Linux will start booting