Access to DDR in M4

[fantasylsdo]

Deaers,

I'm using stm32mp151fad and would like to transfter sram data to ddr in M4 side. I refer to the logic analyzer example https://github.com/STMicroelectronics/logicanalyser. The sram data could be copied into ddr immediately.  

 

// mask and transfer first SRAM buff

 

        uint32_t * pSource = (uint32_t *)&mSampBuff[0];

        uint32_t * pDest = (uint32_t *)(mArrayDdrBuff[mArrayDdrBuffIndex].physAddr+mRollingCompSampCount);

        // we have a buffer of mSramPacketSize/2 bytes, to send by packet of 4 => loop on mSramPacketSize/8

        for (int i=0; i<mSramPacketSize/8; i++) {

        *(pDest+i) = *(pSource+i) & 0x7F7F7F7F; // 76µs to perform this operation, a memcpy takes 104µs

        }

 

But when I tried it, the program will go to crash. The destination address is 0xf7841000.

 

Here is my etzpc configuration in tf-a. and I use spmin instead of optee.

DECPROT(STM32MP1_ETZPC_DDRCTRL_ID, DECPROT_NS_R_S_W, DECPROT_LOCK)
DECPROT(STM32MP1_ETZPC_DDRPHYC_ID, DECPROT_NS_R_S_W, DECPROT_LOCK)

Do you have any thoughts about its root cause?

[fantasylsdo]

I use 1GB DDR. And I find it's strange that M4 could write/read DDR address 0xd0000000， but 0xf7841000 still can't. Do I misconfigure anything? The DDR size is already to set to 1GB in device tree.

[Jean-Christophe_TROTIN]

Hi @fantasylsdo,

 

About the DDR configuration, I would like to point out the following wiki article: https://wiki.st.com/stm32mpu/wiki/How_to_configure_a_256MB_DDR_mapping_from_STM32_MPU_Distribution_Package.

It might be useful to cross-check if you configure correctly for 1GB DDR.

 

Hope this information helps.

 

Regards,

JC.

[fantasylsdo]

Hello Christphone,

Thanks for your kind reply. I checked the dts. The memory size is 1GB.

memory@c0000000 {
device_type = "memory";
reg = <0xC0000000 0x40000000>;
};

 

And here is the output of /proc/iomem.

c0000000-cfffffff : System RAM
c0008000-c0ffffff : Kernel code
c1100000-c125dd3f : Kernel data
d3200000-fffffffe : System RAM

Do I mis-configure other things?

 

Regards,

fantasylsdo