Clock conflict when booting M7 from U-Boot

[Thinh]

Hello NXP Supporters,

I created a simple app on M7 with feature IPCF, FlexCAN and I want to start M7 app in U-boot by startm7 command (Please check my complete project).

I. I follow below commands to start M7 app:

1. dcache off

2. mw.q 0x34100000 0x0 0x40000

3. fatload mmc 0:1 0x80000000 IPCF_Example_S32G399A_M7_0.bin

4. cp.b 0x80000000 0x34300000 0x300000

5. startm7 0x34500400

6. boot

II. Running with Clock_Ip_Init

If I running with Clock_Ip_Init, U-boot will stop immediately after startm7 command, as i understand clock is already initialized, if i run this command clock will re-init then u-boot broken

If i running without Clock_Ip_Init, everything is normal except CAN, i think CAN clock is not same as i config then CAN baudrate is wrong, i receive a error CAN frame

III. Try CAN working by boot M7 only by Flash and IVT blob image:

I also try run M7 app only with Clock_Ip_Init, CAN is running normal, that mean clock for CAN config is ok.

=> Please help/suggest how to keep CAN working when boot M7 app from U-boot ?

[chenyin_h]

Hello, @Thinh 

Thanks for your post.

1. From A core side, the CAN clock may set by the TFA, which may not fulfill the settings used from M core side, so that the CAN may not work correctly with your M core applications

2. For running M core and A core applications simultaneously, it is suggested following the way shown in AN13750, not directly via the u-boot.

BR

Chenyin

[Thinh]

Hello @chenyin_h,

Thank for your response,

Our long-term goal is build bootloader to boot for A53, M7,... simultaneously (following AN13750)

but in short-term, we need to bring everything up to proof of concept first, can you mention the name of document or link that i can refer to do the option 1 (config/rebuild TFA) ?

[chenyin_h]

Hello, @Thinh 

Thanks for your reply.

1. Sorry that there is not a formal document existed for running M core application from u-boot.

2. Generally, if you do want to start the M7 application from A core side(uboot), then you may check if the corresponding resources(like pin/memory/clock) would not be initialized or used simultaneously, you may try only setting the resources on one side to avoid confliction. 

Usually, it does not only need to reconfigure/build TFA/uboot/linux, but also need additional code changes on M/A side according to different requirments.

BR

Chenyin

[Thinh]

Hi @Joey_z, @alejandro_e 

Do you have any suggestion ?

Sorry for this inconvenient.

[alejandro_e]

Hello @Thinh,

As mentioned by my colleague @chenyin_h, the bootflow you are using is not a setup we encounter frequently and thus, we cannot offer much support on it. I would also recommend creating a multi-core bootloader based on the AN13750, and also please check the Bootloader-User-Manual.pdf that comes with the GoldVIP package. 

To avoid mixing topics, please create a new post or a new support ticket for the bootloader topic if you need guidance from our side.