M4 not booting on iMX6SoloX Sabre SD

[tonioch]

Hello every one,

I'm working on iMX6SX Sabre-SDB platform. I'm currently trying to boot the M4 from the QSPI flash by following the document i.MX_6_Linux_Reference_Manual.

So, I renamed a basic printk application to m4_qspi.bin and I copied it on the first VFAT partition of the bootable SD card.

Then, in U-boot on the A9's side (UART1), I enter the following commands :

=> run update_m4_from_sd

SF: Detected N25Q256 with page size 256 Bytes, erase size 4 KiB, total 32 MiB

reading m4_qspi.bin

368 bytes read in 24 ms (14.6 KiB/s)

SF: 65536 bytes @ 0x0 Erased: OK

SF: 368 bytes @ 0x0 Written: OK

=> run m4boot

SF: Detected N25Q256 with page size 256 Bytes, erase size 4 KiB, total 32 MiB

## Starting auxiliary core at 0x78000000 ...

I can see that these two commands are working because of the answers of u-boot. Nevertheless, nothing is displayed on the M4's side (UART2).

Moreover, when I try to boot the A9's Linux image, the following error is displayed and I can't have access to the kernel anymore:

Kernel panic - not syncing: Attempted to kill init! exitcode=0x0000000b

Is there something more to do in order to boot an image from QSPI to M4?

Could somebody tell me where I could find another M4's demo application to test?

One last thing, I'm using the distribution provided by Freescale with the evaluation board (L3.10.53_1.1.0_ga+g496fbe0).

Thanks

[LuisCasado]

Hello,

Try to change the device tree:

setenv fdt_file imx6sx-sdb-m4.dtb

And add to boot parameters ‘uart_from_osc'

setenv mmcargs 'setenv bootargs no_console_suspend clk_ignore_unused uart_from_osc console=${console},${baudrate} root=${mmcroot}'

Regards,

Luis

[tonioch]

Hi Luis,

I tried the modification you suggested and it permits to boot the A9 even if the M4 is already up. So I don't have the kernel panic error anymore, thanks a lot.

Otherwise, do you know where I could find another image for the M4 like an idle image, which simply go to low frequency mode if I enter "S" on the M4 side?

Regards,

Antoine

[LuisCasado · Accepted solution]

Hi Antoine,

We don't have exactly that application, but you can use MQX to generate the application you want. Or the idle application mentioned in the AN5050 perhaps can help you.

Best Regards,

Luis

[tonioch]

Hi Luis,

Yes the idle application mentioned in the AN5050 is exactly the one I need. But, unless I've mistaken, there is no indication in this document about where to find it.

Do you have some information about it? Do I have to use MQX to generate an equivalent?

Regards,

Antoine

[LuisCasado]

Hello,

I have only the attached binary .

Luis

[tonioch]

Hello Luis,

Sorry to bother you again but do you have the binary's source code ?

Thanks

[tonioch]

Great it works now, I'm able to see something on the M4's side and to enter to low-power mode by pressing "S".

Thanks a lot Luis.