[Discuss-gnuradio] Re: libusb error on Mac OS X when building uhd driver

[Elvis Dowson]

Hi,

      More specifically, there is a problem with calls to libusb_cpu_to_le16(x) in libusb.h

/** \def libusb_cpu_to_le16

 * \ingroup misc

 * Convert a 16-bit value from host-endian to little-endian format. On

 * little endian systems, this function does nothing. On big endian systems,

 * the bytes are swapped.

 * \param x the host-endian value to convert

 * \returns the value in little-endian byte order

 */

#define libusb_cpu_to_le16(x) ({ \

union { \

uint8_t  b8[2]; \

uint16_t b16; \

} _tmp; \

uint16_t _tmp2 = (uint16_t)(x); \

_tmp.b8[1] = _tmp2 >> 8; \

_tmp.b8[0] = _tmp2 & 0xff; \

_tmp.b16; \

})

This is called 4 times at line number 886,887,888 and 936 in libusb.h. I just commented it in the following code fragments , which allowed me to complete the build:

static inline void libusb_fill_control_setup(unsigned char *buffer,

uint8_t bmRequestType, uint8_t bRequest, uint16_t wValue, uint16_t wIndex,

uint16_t wLength)

{

struct libusb_control_setup *setup = (struct libusb_control_setup *) buffer;

setup->bmRequestType = bmRequestType;

setup->bRequest = bRequest;

// setup->wValue = libusb_cpu_to_le16(wValue);

// setup->wIndex = libusb_cpu_to_le16(wIndex);

// setup->wLength = libusb_cpu_to_le16(wLength);

}

static inline void libusb_fill_control_transfer(

struct libusb_transfer *transfer, libusb_device_handle *dev_handle,

unsigned char *buffer, libusb_transfer_cb_fn callback, void *user_data,

unsigned int timeout)

{

struct libusb_control_setup *setup = (struct libusb_control_setup *) buffer;

transfer->dev_handle = dev_handle;

transfer->endpoint = 0;

transfer->type = LIBUSB_TRANSFER_TYPE_CONTROL;

transfer->timeout = timeout;

transfer->buffer = buffer;

if (setup) {

// transfer->length = LIBUSB_CONTROL_SETUP_SIZE

// + libusb_le16_to_cpu(setup->wLength);

}

transfer->user_data = user_data;

transfer->callback = callback;

}

The gcc compiler version is the default one supplied with the latest version of xcode (3.2.3)

i686-apple-darwin10-gcc-4.2.1:

Best regards,

Elvis