How to compile ARM EABI toolchain?

Question

i'm going to compile kernel for my aarch64 based device

kernel sources are ready.

and kernel docs are saying that i should use arm-eabi-4.9 toolchain for ARM EABI for compilation kernel.

but what is it? different type of GCC compiler or what?

is it same as GCC 4.9 ?

why i want to know this because i want to make some modifications into compiler so how can i build arm-eabi-4.9 toolchain for ARM EABI from source ?

i have made some research on the net but i found building process of gcc 4.9 and some info about arm-none-eabi..

i have made modifications originally on top of GCC 4.9 this

can i use this sources and then building GCC 4.9 toolchain for arm,aarch64 ---> and then building kernel with using this toolchain ?

Answer 1

When compiling gcc, some configuration flags build it as a cross compiler... You can only build gcc binaries for one pair of host/target architectures. When host and target are the same, you get a normal gcc compiler. If not, you get a cross compiler.

To set the target you need to add the --target option when running ./configure

A toolchain is a gcc crosscompilier for an architecture + some basic libraries (like glibc). You'll need to build those too...

toolchain names go by arch [-vendor] [-os] - eabi

arm-none-eabi , is a crosscompiler for baremetal ARM (no OS).

arm-linux-gnueabi is a crosscompiler for ARM binaries that'll run under a and ARM linux OS using eabi ( Use this for building kernels too).

Also those are arm toolchains, you're looking for aarch64-linux-gnu

Consider looking for a prebuilt toolchain (linaro, embedian), there is some fine tuning required, so it's better to start with a working binary, and running gcc -v to show how it was built.