IMX6SX problem running M4 and A9 both on DDR

[alancasinelli]

Hi everyone,

I'm trying to have both the m4 and a9 boot from ddr since my custom board (based on the imx6sx-sabresd) doesn't have the qspi flash.

If I directly boot linux (kernel version 3.10.53) on the a9, without removing the reset on the m4 everything works just fine.

Following this guide:  How to Run the MQX™ RTOS on Various RAM Memories for i.MX 6SoloX I was able to load the "hello" example of the MQX RTOS at the address 0x80000000 and then run it through "bootaux 0x80000000" using u-boot. The m4 core is working fine since I am able to see the "Hello World" from the m4 console being printed.

However if I try to boot linux after booting the M4 core, I get stuck at:

Kernel image @ 0x81800000 [ 0x000000 - 0x54a908 ]
## Flattened Device Tree blob at 83000000
   Booting using the fdt blob at 0x83000000
   Using Device Tree in place at 83000000, end 8300e893
switch to ldo_bypass mode!
Starting kernel ...

And nothing happens later.

I also tried appending "uart_from_osc"  in the mmcargs variable in u-boot, but still nothing changes.

Has anyone experienced the same problem?

Thanks for your help.

[mirkoardinghi1]

I have a similar problem , I have a kernel panic.

Any help?

[alancasinelli · Accepted solution]

I actually solved this.

The .dts file in the kernel version 3.10.53 doesn't include some necessary modifications needed to boot both the a9 and m4.
I just added this file imx6sx-sdb-m4.dts to my board .dts file. Even if it is for the 3.14.58 kernel version, it worked just fine for me.

The "uart_from_osc" command will make sure that the m4 console won't get corrupted when both the a9 and m4 are running.

Hope this will help you.

[chandiniindavar]

Hi Alan,

even i have same problem kernel locks after loading m4 when i try to boot

I am using IMX7D board

have imx7d-sdb.dts file .. where exactly i have to copy ..i copied to my board SDCARD but still same response .

Could you please tell me where i have to copy

Thanks in advance

[chandiniindavar]

problem solved by doing this:

$ setenv fdt_file imx7d-sdb-m4.dtb

$ save

[mirkoardinghi1]

Thanks, it works!