Andy, > Your driver runs in kernel space. The kernel has the SPE bit off. > The MSR state is process-specific. If the code executes, the > MSR bit > is set. Why do you want to see if the bit is set?
OK, this is a bad idea to use a driver to check the msr register. I don't especially want to see if the bit is set, I just want to improve the board performance for a Linux application :-). To check the performance, I used the Dhrystone 2.1 benchmark with the standard glibc (strcpy, strcmp, ...) on one part, and with the freescale SPE library on the other part (vstrcpy, vstrcmp, ...). I already verified in the binary elf file that the right functions are called. When I run the benchmark, I get the same MIPS with and without SPE code. I ran the same benchmark on the same board without OS, with a personal pseudo glibc, I have the same MIPS as under Linux, with the freescale library, I gain 40% of perf. That's I want to retreive with the Linux OS. Regards G?rard
