On Mon, Jul 28, 2003 at 11:36:10PM -0400, Charles Lepple wrote: > I took a look at porting libsensors to work with the new /sys interface > to the sensor readings, and I have a few questions. I think an almost entirely new api and rewrite will be necessary, not merely a port. But that's just my opinion after studying the current code, not as one who is doing any actual work on it :) > First, let me explain the scope of this attempt: I already have the > 2.6.0test2 i2c and sensor kernel drivers working, so I just want to > make the userspace tools (libsensors, basically) work with the new > paths. That means that I'm setting COMPILE_KERNEL to 0 in the > lm_sensors makefile. Compiling the lm_sensors kernel/ directory is > going to be different than in 2.4, I'm afraid-- the out-of-kernel build > process changed for the ThinkPad driver modules, and I think it'll be > different here too. > > So is there any need to include the kernel headers when compiling other > parts of lm_sensors? In particular, I ran into trouble with the 2.6 > version of linux/sysctl.h, and disabling $(LINUX_HEADERS) in the > makefile (by setting it to '.') picked up /usr/include/linux/sysctl.h, > which resulted in a much happier compiler. NEVER use kernel header files from userspace!!! Use the glibc sanitized ones that your glibc is built against. If not, bad things will happen. > Also, I noticed the use of the numerical sysctl interface. Is that > required for some 2.4 kernels? I would imagine that most people who are > running 2.4 also have /proc mounted, so it might make sense to combine > some code and just check for /proc or /sys files. In 2.6, using > sysctl() yields this in the logs at every invocation of the program: > > sensors: numerical sysctl 7 2 1 is obsolete. > > so for short-lived polling programs, it might make sense to check for > /proc or /sys before attempting the system call. sysctl is not needed for sensor stuff in 2.6. Good luck, greg k-h
