I'm using Android 2.3.3 and I want to copy the iwconfig file to /system/xbin. First I tried doing it with adb push using this:
adb push iwconfig /system/xbin
But in return I had: failed to copy 'iwconfig' to '/system/xbin/iwconfig': Permission denied
So I made my research and finally found this mount command that actually worked (most of them returned the usage: mount ... line)
mount -o remount,rw /dev/block/mtdblock4 /system
But even with that I'm still having the "Permission denied" line.
I also tried
mount -o remount,rw /dev/block/mtdblock4 /system/xbin
Buth it returned "Invalid Argument"