Hi, David, Sangmoon and all: Thanks for all the input. Now i understand why m8xx_pcmcia.c needs to use io_block_mapping. If we can use ioremap in the driver, then we don't need to map the io mem in kernel init. Maybe we can do some improvement later on this driver. regards ** Sent via the linuxppc-embedded mail list. See http://lists.linuxppc.org/