my @rpi_v2_gpio_p1;
for ( @Device::BCM2835::EXPORT_OK ) {
   next if !/^RPI_V2_GPIO_P1_(\d+)\z/;
   my $pin = 0 + $1;
   my $val = ( \&{"Device::BCM2835::$_"} )->();
   $rpi_v2_gpio_p1[ $pin ] = $val;
}