Copy Cisco IOS from router to tftp Mac OSX

Install tftp server for Mac or enable tftp server using 

sudo launchctl load -w /System/Library/LaunchDaemons/tftp.plist 

Create file name  on server l

sudo touch /private/tftpboot/"filename.bin"

Change permission for the file 

sudo chmod a+w /private/tftpboot/"filename.bin"

On router type this command 

R1#copy flash: tftp:

Source filename [filename.bin]? 

Address or name of remote host []? 192.168.2.10      

Destination filename ["filename.bin"]? /private/tftpboot/"filename.bin"