We have designed a board based on the iMX8MP and the iMX8MP EVK. This board has similar LPDDR4 memory, just 3 GBytes rather than 6 GBytes. We are trying to bring the board up using a standard iMX8MP EVK Yocto build to start with. It is booting to u-boot but then hanging after "DRAM: ". We understand that the memory size is hardcoded so we are trying to change that but we are unsure how there does not seem to be solid info on how to do this.
We have edited the uboot include/configs/imx8mp_evk.h setting PHYS_SDRAM_SIZE, PHYS_SDRAM_2 and PHYS_SDRAM_2_SIZE:
#define PHYS_SDRAM 0x40000000
#define PHYS_SDRAM_SIZE 0x80000000 /* 2 GB */
#define PHYS_SDRAM_2 0xC0000000
#define PHYS_SDRAM_2_SIZE 0x40000000 /* 1 GB */
And edited the uboot arch/arm/dts/imx8mp-evk.dts:
memory@40000000 {
device_type = "memory";
reg = <0x0 0x40000000 0 0x80000000>,
<0x1 0x00000000 0 0x40000000>;
};
Although this runs on the EVK board and reports a memory size of 3GBytes at the uboot and Linux levels, it still hangs on our prototype board. We presume that the tee.bin and maybe bl31.bin have hard coded addresses as well, reading some things.
We are happy to disable optee for now, but can't see how. The manual "i.MX Yocto Project Users Guide" states:
5.6.10 OP-TEE enablement
OP-TEE requires three components: OP-TEE OS, OP-TEE client, and OP-TEE test. In addition, the kernel and U-Boot have
configurations. The OP-TEE OS resides in the bootloader while the OP-TEE client and test reside in the rootfs.
OP-TEE is enabled by default in this release. To disable OP-TEE, go to the meta-imx/meta-bsp/conf/layer.conf file and
comment out the DISTRO_FEATURES_append for OP-TEE and uncomment the removed line.
Bit the meta-imx/meta-bsp/conf/layer.conf file has no "DISTRO_FEATURES_append for OP-TEE".
1. Any ideas on how we disable the Yocto optee build for the imx8mp_evk ?
2. Any ideas on what should we change in the imx8mp_evk build for 3 GBytes rather than 6 GBytes of LPDDR4 (same memory type other than size) ?
Terry
