I'm new to reverse engineering.
I only want to add an app to my sat receiver.
To start I tried to extract my firmware with
./extract-firmware, it's ok, and I have 1 ecos RTOS, and two cramfs in fmk/
BUT when I rebuild without any change, I have a message
Building new cramfs file system... (this may take several minutes!) Directory data: 464 bytes Everything: 1392 kilobytes Super block: 76 bytes CRC: b79c2a52 Remaining free bytes in firmware image: 856064 Processing 0 header(s) from /home/thehou/firmware-mod-kit/fmk/new-firmware.bin... CRC update failed. Firmware header not supported; firmware checksums may be incorrect. New firmware image has been saved to: /home/thehou/firmware-mod-kit/fmk/new-firmware.bin`
So before I continue to add an app into my sat receiver, I want to know how can I rebuild my extracted firmware.
Perhaps must I extract with binwalk, but I don't know how to rebuild!
Thanks for your help.
Reference : this is the receiver firmware