Hi, Who wrote the program in file $/libplatsupport/plat_include/omap4/platsupport/plat/gpt_constants.h , GPT4_DEFICE_PADDR is wrong spelled, it should be GPT1_DEVICE_PADDR. static void *paddrs[] = {(void *) GPT1_DEVICE_PADDR, (void *) GPT2_DEFICE_PADDR, (void *) GPT3_DEFICE_PADDR, (void *) GPT4_DEFICE_PADDR, (void *) GPT5_DEFICE_PADDR, (void *) GPT6_DEFICE_PADDR, (void *) GPT7_DEFICE_PADDR, (void *) GPT8_DEFICE_PADDR, (void *) GPT9_DEFICE_PADDR, (void *) GPT10_DEFICE_PADDR, (void *) GPT11_DEFICE_PADDR}; Xilong Pei Tongji University 2014/11/19