Error "Unable to locate package gcc-arm-none-eabi debian"

I want to compile C code on my BeagleBone Black board which has an ARM Cortex-A8. My operating system is Debian. When I run the makefile, I've get:

no such file or directory: 'arm-none-eabi'

So I tried to install this package, but I've got:

unable to locate package gcc-arm-none-eabi

I searched over the web and found different solutions, but none of them worked for me. For example, I've already edited the source.list and added the emdebian FTP address as a source address. However, I couldn't install this package at all.