hello kimjishu,
OC ALARM it means over-current events, which are handled in hardware.
when OC throttling is happening, there is an interrupt from bpmp to cpu, the tegra_oc_event driver detects the interrupt and then increments the interrupt count and prints those kernel logs.
you may also access TRM, please check SOC_THERM for more details.
this mean the thermal trip is enabled, and system will then be shutdown directly by PMIC instead of causing a shutdown through Boot ROM.