2008-07-29 10:15:35 blackfin uclinux and memory protection
murti iki (GERMANY)
I am wondering if a user space application can access the hardware registers directly. So far
I thought that since a user space application runs in user_mode, accessing a hardware
register would cause an exception to occur. However I have recently came across the
"makig the blackfin perform" article in wiki and there CYCLES register is accessed directly
from a user space program.
Is it the case that some hardware registers like CYCLES can be accessed while peripheral
thank you for your help
2008-07-29 11:08:44 Re: blackfin uclinux and memory protection
Mike Frysinger (UNITED STATES)
CYCLES is a core register, it is not a system or core register (MMR). unfortunately, it is R/W for user and higher.
review the Blackfin PRM/HRM if you really want to know access permission modes (user vs supervisor vs emulation).