IMX8M Mini Custom Board Cortex M4 issue

[Dhevan]

Hi,

Imx8m mini evk we can able to activate m4 core. But same configuration for our custom board doesn't working (UART4 does not printing Hello world example).

ATF we have added UART4 permission.

Custom board we have used PCA9450 pmic anything we need to changes for M4 core ?

Why same configuration does not working on our custom board ?

Thanks & Regards,

        Vasu

[AldoG]

Hello,

What do you mean by added permition?
Please note that we do not add anything into ATF since UART4 is the default for M4

Could you share the changes you have with reference to i.MX8MMini EVK?

Best regards,
Aldo.

[Dhevan]

Hi Aldo,

In ATF - imx8mm_bl31_setup.c changed to

Before :
static const struct imx_rdc_cfg rdc[] = {
    /* Master domain assignment */
    RDC_MDAn(RDC_MDA_M4, DID1),
 
    /* peripherals domain permission */
    RDC_PDAPn(RDC_PDAP_UART4, D0R | D0W), 
After:
static const struct imx_rdc_cfg rdc[] = {
    /* Master domain assignment */
    RDC_MDAn(RDC_MDA_M4, DID1),
 
    /* peripherals domain permission */
    RDC_PDAPn(RDC_PDAP_UART4, D1R | D1W),   

I have changed imx8mm-evk.dts to imx8mm-evk-rpmsg.dts it's booting fine.

Uboot command i have modified.

setenv fdt_file imx8mm-evk-rpmsg.dtb

fatload mmc 2:1 0x48000000 imx8mm_m4_TCM_hello_world.bin
cp.b 0x48000000 0x7e0000 35000
bootaux 0x7e0000
boot

In custom board i did same thing but UART4 does not printing any thing.

Thanks & Regards,

      Vasu

[AldoG]

Hi,

In the changes to ATF, by default we have the same configuration for the EVK:

RDC_PDAPn(RDC_PDAP_UART4, D1R | D1W)

It does confuse me a bit when you mention that before it was

RDC_PDAPn(RDC_PDAP_UART4, D0R | D0W)

Since the last gives the peripheral domain to the Cortex-A, please confirm which of the two you have. As I said before in our default configuration UART4 is the terminal for Cortex-M, no changes should be needed to ATF.

Please let me know the BSP version you're using as a reference.

Best regards,
Aldo.