Running user application in OCRAM on iMX8MP

nitzant — Wed, 07 Aug 2024 12:32:39 GMT

I'm working on i.MX8MP evaluation board and I want to isolate one of the four CPUs and run an user application on it from OCRAM memory. For some reason, I don't see an entry for the OCRAM memory region in /proc/iomem (Is it legit?). Can you please advise how should be the approach in this case?

Some dry details:

I'm using a Linux kernel from 'nxp-real-time-edge-sw/real-time-edge-linux' repository - Tag lf-6.1.22-rt-2.0.0
I build my ROOTFS via buildroot (a minimized root file system for arm64).
This is how the OCRAM is defined in "imx8mp.dtsi":

resmem: reserved-memory {
#address-cells = <2
#size-cells = <2>
ranges;

ocram: ocram@900000 {
no-map;
reg = <0 0x900000 0 0x70000>;
};

};

Re: Running user application in OCRAM on iMX8MP

Bio_TICFSL — Wed, 07 Aug 2024 14:05:00 GMT

Hello,

first please look at

System Controller Firmware 101 - Resource management service

memory from OCRAM address start to 0x118000 is allocated to ATF partition,

refer to #define OCRAM_ALIAS_SIZE 0x18000, OCRAM_BASE + OCRAM_ALIAS

It is not recommended to use it as it is reserved for internal usage in nxp software.

May be suggested to proceed with help of extended support of

NXP Professional Services | NXP

Regards

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Running user application in OCRAM on iMX8MP

Re: Running user application in OCRAM on iMX8MP