I am trying to reduce power consumption of the PicoCoreMX8MP while the Linux kernel is in suspend mode and the Cortex-M7 core is in RUN mode.
Therefore, I'm trying to follow the suggestions in AN13400, which require changes to the ATF.
If I understand correctly: to integrate these changes, I must rebuild Nboot with the adjusted ATF. My question is then what is the recommended way of doing this?
Do I simply compile bl31-imx8mp.bin from the adjusted ATF along with the other files mentioned in u-boot-fus/board/F+S/fsimx8mp/nboot/Makefile (shown below) and then run the nboot make target from the root of u-boot-fus? Is there a yocto recipe or other reference for this?
Code
- NXP_DDR3L = ddr3_imem_1d.bin ddr3_dmem_1d.bin
- NXP_LPDDR4 = lpddr4_pmu_train_1d_imem$(DDR_FW_VERSION).bin lpddr4_pmu_train_1d_dmem$(DDR_FW_VERSION).bin \
- lpddr4_pmu_train_2d_imem$(DDR_FW_VERSION).bin lpddr4_pmu_train_2d_dmem$(DDR_FW_VERSION).bin
- NXP_DDR4 = ddr4_imem_1d$(NANO).bin ddr4_dmem_1d$(NANO).bin \
- ddr4_imem_2d$(NANO).bin ddr4_dmem_2d$(NANO).bin
- NXP_ATF = bl31-imx8mp.bin
- NXP_TEE = tee-fsimx8mp.bin