Start of self-made OS 1. Environment construction

Yes, let's make an OS!

So, I would like to make an OS. This time, let's get to the point of getting a GCC cross-compiler.

What to prepare

• Ubuntu 20.04

1. Dependency installation

First, install the dependencies.

What you need is:

• curl
• build-essential, m4
• libgmp3-dev, libmpc-dev, libmpfr-dev
• qemu, qemu-kvm

You can use curl as you like, such as wget.

$ sudo apt update
$ sudo apt -y install curl build-essential m4 libgmp3-dev libmpc-dev libmpfr-dev qemu qemu-kvm

2. Build gmp, mpfr, mpc, binutils

First, make gmp. It is set to --prefix = / usr / local / cc, but you can use it as you like. However, I think it is better to make the value specified by this --prefix common to gmp, mpfr, mpc, and binutils.

First from gmp.

gmp

$ curl --output gmp-6.2.0.tar.bz2 https://ftp.gnu.org/gnu/gmp/gmp-6.2.0.tar.bz2
$ tar -xvf gmp-6.2.0.tar.bz2
$ cd gmp-6.2.0
$ ./configure --prefix=/usr/local/cc
$ make check && sudo make install
$ cd ..

Next, make in the order of mpfr, mpc, binutils.

mpfr

$ curl --output mpfr-4.1.0.tar.bz2 https://ftp.gnu.org/gnu/mpfr/mpfr-4.1.0.tar.bz2
$ tar -xvf mpfr-4.1.0.tar.bz2
$ cd mpfr-4.1.0
$ ./configure --prefix=/usr/local/cc
$ make check && sudo make install
$ cd ..

mpc

$ curl --output mpc-1.2.0.tar.gz https://ftp.gnu.org/gnu/mpc/mpc-1.2.0.tar.gz
$ tar -xvf mpc-1.2.0.tar.gz
$ cd mpc-1.2.0
$ ./configure --prefix=/usr/local/cc
$ make check && sudo make install
$ cd ..

binutils

$ curl --output binutils-2.35.tar.xz https://ftp.gnu.org/gnu/binutils/binutils-2.35.tar.xz
$ tar -xvf binutils-2.35.tar.xz
$ cd binutils-2.35
$ ./configure --target=x86_64-elf --prefix=/usr/local/cc --disable-nls
$ make
$ make install
$ cd ..

3. Build gcc

Well, finally GCC make. Here are some caveats. The first is that you should go into the gcc source code directory and do not ** ./configure **. If you do that, you can do it with make all-target-libgcc. The second is the configure argument --with-xxx. For this, specify the directory specified by --prefix of gmp, mpfr, mpc in the previous step. The third is the --with-as argument. This, unlike others, requires you to specify the ** execution binary path ** directly.

gcc make

$ curl --output gcc-10.2.0.tar.xz https://ftp.gnu.org/gnu/gcc/gcc-10.2.0/gcc-10.2.0.tar.xz
$ tar -xvf gcc-10.2.0.tar.xz
$ mkdir gcc-make-tmp
$ cd gcc-make-tmp
$ ../gcc-10.2.0/configure\
    --target=x86_64-elf\
    --prefix=/usr/local/cc\
    --disable-nls\
    --enable-languages=c\
    --without-headers\
    --with-gmp=/usr/local/cc\
    --with-mpfr=/usr/local/cc\
    --with-mpc=/usr/local/cc\
    --with-as=/usr/local/cc/bin/x86_64-elf-as #Specify the binary path of the as command
    #You may get sick without this(stdio.h: no such file or directory.)
    #Add if you can
    # --with-headers=/usr/include\
    # --with-headers=/usr/include/x86_64-linux-gnu
$ #It takes a long time, so let's take a tea break while executing this command.
$ make all-gcc && make install-gcc
$ make all-target-libgcc && make install-target-libgcc

4. Test

$ export PATH=/usr/local/cc/bin:$PATH
$ x86_64-elf-gcc -v
Using built-in specs.
COLLECT_GCC=x86_64-elf-gcc
COLLECT_LTO_WRAPPER=/mnt/d/usr/local/cc/libexec/gcc/x86_64-elf/10.2.0/lto-wrapper
Target: x86_64-elf
Configured with: (abridgement)
Thread model: single
Supported LTO compression algorithms: zlib
gcc version 10.2.0 (GCC)

If such an output is made, it is successful. Thank you for your hard work.

5. Impressions

I had a hard time because there was little information. Especially the last gcc make was tough.

** Build binutils from source. ** **