Memory size of HiFi4 Core on i.MX 8M Plus

[StXue]

Hello,
I have some doubts about the memory size of HiFi4 Core.

In memory map of Context-A53 and Context-M7, I found a same region "Audio DSP" memory bus address form 3B00_0000 to 3BFF_FFFF 16MB. Is this the shared memory between multiple cores?

But in memory map of HiFi4, most of them are reserved, like 3B77_0000 3BFF_FFFF. 

Does it mean on HiFi4, we only have 256KB OCRAM_A and 64KB DTCM memory can be used?

Because on MX RT685, I can assign more memory to DSP Core, from ARM side.

Look forward to your favourable reply, thanks!

[StXue]

Thank you for your support.

[joanxie · Accepted solution]

the Linux OS kernel reserves the memory for the DSP in the SDRAM separately. The range of the reserved
memory is 0x92400000 ~ 0x943fffff (32 MB). You may set this reserved memory by changing the imx8mp.dtsi file in the

"https://source.codeaurora.org/external/imx/linux-imx/tree/arch/arm64/boot/dts/freescale/imx8mp.dtsi?..."

reserved-memory {
…………….
dsp_reserved: dsp@92400000 {
reg = <0 0x92400000 0 0x1000000>;
no-map;
};
dsp_reserved_heap: dsp_reserved_heap {
reg = <0 0x93400000 0 0xef0000>;
no-map;
};
dsp_vdev0vring0: vdev0vring0@942f0000 {
reg = <0 0x942f0000 0 0x8000>;
no-map;
};
dsp_vdev0vring1: vdev0vring1@942f8000 {
reg = <0 0x942f8000 0 0x8000>;
no-map;
};
dsp_vdev0buffer: vdev0buffer@94300000 {
compatible = "shared-dma-pool";
reg = <0 0x94300000 0 0x100000>;
no-map;
};