thanks for Scott's following > You need to pass your physical address (0xd0000000) to ioremap() to > obtain a virtual address that you can dereference.
actually, i have done that like you said. pass my phy addr to a virtual addr, but i suppose it is a kernel virtual addr. i wanna get data from phy in my application of user space. i try it by copy_to_user transfer a kernel virtual addr to a use virtual addr for using by user. but copy_to_user failed... i do it like this ssize_t read(....,char *buf,....,....) { .... kernel_buf = (void *)ioremap(0xD0000000, 4096); copy_to_user(buf, kernel_buf, 4096); .... } -- View this message in context: http://www.nabble.com/PPC8247-booting-error-tp23381214p23438722.html Sent from the linuxppc-dev mailing list archive at Nabble.com. _______________________________________________ Linuxppc-dev mailing list Linuxppc-dev@ozlabs.org https://ozlabs.org/mailman/listinfo/linuxppc-dev