I am very new to linux I have an ARM based board /platform based on Kirkwood processor and I am trying to build a working system from scratch. My primary boot loader is U-boot which works fine I have built Kernel 3.5.2 which loads and appears to run fine with Busybox v 1.19.4. I am booting straight from the SD card formatted with ext3 and a very basic rootfs. Everthing appears to operate correctly I have developed a set of initialisations which give me a working platform. However I appear to have an issue with file saving if I edit a file using for instance nano everything appears to be fine it saves ok or says it does if I do a cat on the file the changes are there. If i then reboot (switch on and off) when I go back and look at the file the changes are not there. I would appear that the changes are residing in RAM but are not getting updated to the SD card, this is also an issue with commands such as cp. I am not loading or booting using initrd or initramfs but working straight from the sd card. Any ideas or suggestions greatfully received.