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Altera_Forum's avatar
Altera_Forum
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14 years ago

Using FPU with uCLinux

Hello folks, i'am just trying to use the floating-point-unit within my uCLinux dist. I have added the corresponding custom instruction to the cpu within my sopc-builder system. After that i co...
Altera_Forum's avatar
Altera_Forum
Icon for Honored Contributor rankHonored Contributor
14 years ago

I found out, that the printout of cat /proc/cpuinfo is alway "none" for the FPU entry! See nios2-linux/linux-2.6/arch/nios2/kernel/cpuinfo.c: 

 
count = seq_printf(m,
   "CPU:\t\tNios II/%s\n"
   "MMU:\t\t%s\n"
   "FPU:\t\tnone\n"
   "Clocking:\t%u.%02u MHz\n"
   "BogoMips:\t%lu.%02lu\n"
   "Calibration:\t%lu loops\n",
   cpuinfo.cpu_impl,
   cpuinfo.mmu ? "present" : "none",
   clockfreq / 1000000, (clockfreq / 100000) % 10,
   (loops_per_jiffy * HZ) / 500000, ((loops_per_jiffy * HZ) / 5000) % 100,
   (loops_per_jiffy * HZ));

Does this mean, that FPU isn't supported on the nios2-processor when using uCLinux?