> Are you sure the math.h included is the math.h from eCos? Well, I'm pretty sure. We simply include "#include <math.h>".
Running the following on our ecos tree shows that there is only one instance: $ find . -name math.h ./packages/language/c/libm/current/include/math.h > Could you provide all includes you have in this driver and the C code > that uses the log function ? Sure, #include <pkgconf/system.h> #include <cyg/kernel/kapi.h> #include <pkgconf/io_eth_drivers.h> #include <pkgconf/devs_eth_mxc_ktsradio.h> #include <pkgconf/devs_eth_mxc_fec.h> #include <cyg/infra/cyg_type.h> #include <cyg/infra/cyg_ass.h> #include <cyg/hal/hal_arch.h> #include <cyg/hal/hal_cache.h> #include <cyg/hal/hal_intr.h> #include <cyg/hal/hal_endian.h> #include <cyg/infra/diag.h> #include <cyg/hal/drv_api.h> #include <cyg/hal/hal_soc.h> #include <cyg/hal/hal_mm.h> #include <cyg/hal/hal_if.h> #include <cyg/io/eth/eth_drv.h> #include <cyg/io/eth/netdev.h> #include <cyg/io/ktsradio.h> #include <cyg/io/ktsradio_timers.h> #include <cyg/io/ktsradio_rfcomm.h> // spooled debug printing #include <cyg/debugprint/debugprint.h> // Ethernet packet definitions #include <net/ethernet.h> // crc #include <cyg/crc/crc.h> // queues #include <cyg/queue/queue.h> #include <stdlib.h> #include <math.h> The specific line is in a function that calculates an rssi value: cyg_int16 ktsradio_calcRSSI(rssiRegs_t rssiRegs) { cyg_uint32 nbAgc = rssiRegs.rxBurstAgc & 0xfffff; cyg_uint32 wbAgc = rssiRegs.rxBurstAgc >> 24; cyg_uint16 rssi = 0; double wbGain = (wbAgc/256.0 * 50.0); cyg_uint32 exponent = (nbAgc >> 16); double mantissa = 0.5 + ((double) (nbAgc & 0xffff)/131072.0); ... #define NBK0 (-13000.0) #define NBK1 (870.0) #define NBK2 (-79.0) static double rfRssi; cyg_uint16 rfAuxReading = rssiRegs.rfAgc; ... rfRssi = NBK0/((double)rfAuxReading - NBK1) + NBK2; rssi = (cyg_uint16) round(rfRssi - 6.02*(double)exponent - 20.0*log10(mantissa) - wbGain); ... } Also, I forgot to mention that this is an eCos v2 tree. We are working on updating to v3, but that will take some time. Mike -- Before posting, please read the FAQ: http://ecos.sourceware.org/fom/ecos and search the list archive: http://ecos.sourceware.org/ml/ecos-discuss