From 93e43a82b638a5757ead6296295973c61e024825 Mon Sep 17 00:00:00 2001
From: Eugen Wissner <belka@caraus.de>
Date: Mon, 10 Feb 2025 08:34:08 +0100
Subject: [PATCH] Add cross_toolchain.rb

---
 bin/cross_toolchain.rb | 314 +++++++++++++++++++++++++++++++++++++++++
 1 file changed, 314 insertions(+)
 create mode 100755 bin/cross_toolchain.rb

diff --git a/bin/cross_toolchain.rb b/bin/cross_toolchain.rb
new file mode 100755
index 0000000..b54ee97
--- /dev/null
+++ b/bin/cross_toolchain.rb
@@ -0,0 +1,314 @@
+#!/usr/bin/env ruby
+# This Source Code Form is subject to the terms of the Mozilla Public License,
+# v. 2.0. If a copy of the MPL was not distributed with this file, You can
+# obtain one at https://mozilla.org/MPL/2.0/. -}
+
+# frozen_string_literal: true
+
+require 'uri'
+require 'net/http'
+require 'open3'
+require 'etc'
+require 'fileutils'
+require 'pathname'
+
+BINUTILS_VERSION = '2.43.1'
+GLIBC_VERSION = '2.40'
+KERNEL_VERSION = '5.15.166'
+GCC_VERSION = "14.2.0"
+
+TMP = Pathname.new('./build')
+
+class BuildTarget
+  attr_accessor(:build, :gcc, :target, :tmp)
+
+  def gxx
+    @gcc.gsub 'c', '+'
+  end
+
+  def sysroot
+    tmp + 'sysroot'
+  end
+
+  def rootfs
+    tmp + 'rootfs'
+  end
+
+  def tools
+    tmp + 'tools'
+  end
+
+  def configuration
+    case target
+    when /^riscv[[:digit:]]+-/
+      [
+        '--with-arch=rv32imafdc',
+        '--with-abi=ilp32d',
+        '--with-tune=rocket',
+        '--with-isa-spec=20191213'
+      ]
+    else
+      []
+    end
+  end
+end
+
+def gcc_verbose(gcc_binary)
+  read, write = IO.pipe
+  system({'LANG' => 'C'}, gcc_binary, '--verbose', err: write)
+  write.close
+  output = read.read
+  read.close
+  output
+end
+
+def find_build_target(gcc_version, target)
+  gcc_binary = 'gcc'
+  output = gcc_verbose gcc_binary
+
+  if output.start_with? 'Apple clang'
+    gcc_binary = "gcc-#{gcc_version.split('.').first}"
+    output = gcc_verbose gcc_binary
+  end
+  result = output
+    .lines
+    .each_with_object(BuildTarget.new) do |line, accumulator|
+      if line.start_with? 'Target: '
+        accumulator.build = line.split(' ').last.strip
+      elsif line.start_with? 'COLLECT_GCC'
+        accumulator.gcc = line.split('=').last.strip
+      end
+    end
+  result.tmp = TMP
+  result.target = target
+  result
+end
+
+def download_and_unarchive(url, target)
+  case File.extname url.path
+  when '.bz2'
+    archive_type = '-j'
+    root_directory = File.basename url.path, '.tar.bz2'
+  when '.xz'
+    archive_type = '-J'
+    root_directory = File.basename url.path, '.tar.xz'
+  else
+    raise "Unsupported archive type #{url.path}."
+  end
+
+  Net::HTTP.start(url.host, url.port, use_ssl: url.scheme == 'https') do |http|
+    request = Net::HTTP::Get.new url.request_uri
+
+    http.request request do |response|
+      case response
+      when Net::HTTPRedirection
+        download_and_unarchive URI.parse(response['location'])
+      when Net::HTTPSuccess
+        Open3.popen2 'tar', '-C', target.to_path, archive_type, '-xv' do |stdin, stdout, wait_thread|
+          Thread.new do
+            stdout.each { |line| puts line }
+          end
+
+          response.read_body do |chunk|
+            stdin.write chunk
+          end
+          stdin.close
+
+          wait_thread.value
+        end
+      else
+        response.error!
+      end
+    end
+  end
+  target + root_directory
+end
+
+def configure_make_install(source_directory, configure_options, env, cwd)
+  configure = source_directory.relative_path_from(cwd) + 'configure'
+  system env, configure.to_path, *configure_options, chdir: cwd.to_path, exception: true
+  system 'make', '-j', Etc.nprocessors.to_s, chdir: cwd.to_path, exception: true
+  system env, 'make', 'install', chdir: cwd.to_path, exception: true
+end
+
+# Build cross binutils.
+def binutils(options)
+  source_directory = download_and_unarchive(
+    URI.parse("https://ftp.gnu.org/gnu/binutils/binutils-#{BINUTILS_VERSION}.tar.xz"),
+    options.tools)
+
+  cwd = source_directory.dirname + 'build-binutils'
+  cwd.mkpath
+  options.rootfs.mkpath
+
+  env = {
+   'CC' => options.gcc,
+   'CXX' => options.gxx
+  }
+  configure_options = [
+    "--prefix=#{options.rootfs.realpath}",
+    "--target=#{options.target}",
+    '--disable-nls',
+    '--enable-gprofng=no',
+    '--disable-werror',
+    '--enable-default-hash-style=gnu',
+    '--disable-libquadmath'
+  ]
+  configure_make_install source_directory, configure_options, env, cwd
+end
+
+# Build stage 1 GCC.
+def gcc1(options)
+  source_directory = download_and_unarchive(
+    URI.parse("https://gcc.gnu.org/pub/gcc/releases/gcc-#{GCC_VERSION}/gcc-#{GCC_VERSION}.tar.xz"),
+    options.tools)
+
+  cwd = source_directory.dirname + 'build-gcc'
+  cwd.mkpath
+  options.rootfs.mkpath
+  options.sysroot.mkpath
+
+  system 'contrib/download_prerequisites', chdir: source_directory.to_path, exception: true
+  configure_options = options.configuration + [
+    "--prefix=#{options.rootfs.realpath}",
+    "--with-sysroot=#{options.sysroot.realpath}",
+    '--enable-languages=c,c++',
+    '--disable-shared',
+    '--disable-bootstrap',
+    '--disable-multilib',
+    '--disable-libmudflap',
+    '--disable-libssp',
+    '--disable-libquadmath',
+    '--disable-libsanitizer',
+    '--disable-threads',
+    '--disable-libatomic',
+    '--disable-libgomp',
+    '--disable-libvtv',
+    '--disable-libstdcxx',
+    '--disable-nls',
+    '--with-newlib',
+    '--without-headers',
+    "--target=#{options.target}",
+    "--build=#{options.build}",
+    "--host=#{options.build}"
+  ]
+  flags = '-O2 -fPIC'
+  env = {
+    'CC' => options.gcc,
+    'CXX' => options.gxx,
+    'CFLAGS' => flags,
+    'CXXFLAGS' => flags,
+    'PATH' => "#{options.rootfs.realpath + 'bin'}:#{ENV['PATH']}"
+  }
+  configure_make_install source_directory, configure_options, env, cwd
+end
+
+# Copy glibc headers.
+def headers(options)
+  source_directory = download_and_unarchive(
+    URI.parse("https://ftp.gnu.org/gnu/glibc/glibc-#{GLIBC_VERSION}.tar.xz"),
+    options.tools)
+  include_directory = options.tools + 'include'
+
+  include_directory.mkpath
+  FileUtils.cp (source_directory + 'elf/elf.h'), (include_directory + 'elf.h')
+end
+
+# Build linux kernel.
+def kernel(options)
+  cwd = download_and_unarchive(
+    URI.parse("https://cdn.kernel.org/pub/linux/kernel/v5.x/linux-#{KERNEL_VERSION}.tar.xz"),
+    options.tools)
+
+  env = {
+    'CROSS_COMPILE' => "#{options.target}-",
+    'ARCH' => 'riscv',
+    'PATH' => "#{options.rootfs.realpath + 'bin'}:#{ENV['PATH']}",
+    'HOSTCFLAGS' => "-D_UUID_T -D__GETHOSTUUID_H -I#{options.tools.realpath + 'include'}"
+  }
+  system env, 'make', 'rv32_defconfig', chdir: cwd.to_path, exception: true
+  system env, 'make', '-j', Etc.nprocessors.to_s, chdir: cwd.to_path, exception: true
+  system env, 'make', 'headers', chdir: cwd.to_path, exception: true
+
+  user_directory = options.sysroot + 'usr'
+
+  user_directory.mkpath
+  FileUtils.cp_r (cwd + 'usr/include'), (user_directory + 'include')
+end
+
+# Build glibc.
+def glibc(options)
+  source_directory = options.tools + "glibc-#{GLIBC_VERSION}"
+  configure_options = [
+    '--prefix=/usr',
+    "--host=#{options.target}",
+    "--target=#{options.target}",
+    "--build=#{options.build}",
+    "--enable-kernel=#{KERNEL_VERSION}",
+    "--with-headers=#{options.sysroot.realpath + 'usr/include'}",
+    '--disable-nscd',
+    '--disable-libquadmath',
+    '--disable-libitm',
+    '--disable-werror',
+    'libc_cv_forced_unwind=yes'
+  ]
+  bin = options.rootfs.realpath + 'bin'
+  env = {
+    'PATH' => "#{bin}:#{ENV['PATH']}",
+    'MAKE' => 'make' # Otherwise it uses gnumake which can be different and too old.
+  }
+  cwd = source_directory.dirname + 'build-glibc'
+  cwd.mkpath
+
+  configure = source_directory.relative_path_from(cwd) +'./configure'
+  system env, configure.to_path, *configure_options, chdir: cwd.to_path, exception: true
+  system env, 'make', '-j', Etc.nprocessors.to_s, chdir: cwd.to_path, exception: true
+  system env, 'make', "install_root=#{options.sysroot.realpath}", 'install', chdir: cwd.to_path, exception: true
+end
+
+# Build stage 2 GCC.
+def gcc2(options)
+  source_directory = options.tools + "gcc-#{GCC_VERSION}"
+  cwd = options.tools + 'build-gcc'
+
+  FileUtils.rm_rf cwd
+  cwd.mkpath
+
+  configure_options = options.configuration + [
+    "--prefix=#{options.rootfs.realpath}",
+    "--with-sysroot=#{options.sysroot.realpath}",
+    '--enable-languages=c,c++,lto',
+    '--enable-lto',
+    '--enable-shared',
+    '--disable-bootstrap',
+    '--disable-multilib',
+    '--enable-checking=release',
+    '--disable-libssp',
+    '--disable-libquadmath',
+    '--enable-threads=posix',
+    '--with-default-libstdcxx-abi=new',
+    '--disable-nls',
+    "--target=#{options.target}",
+    "--build=#{options.build}",
+    "--host=#{options.build}"
+
+  ]
+  flags = '-O2 -fPIC'
+  env = {
+    'CFLAGS' => flags,
+    'CXXFLAGS' => flags,
+    'PATH' => "#{options.rootfs.realpath + 'bin'}:#{ENV['PATH']}"
+  }
+  configure_make_install source_directory, configure_options, env, cwd
+end
+
+target = ARGV.fetch 0, 'riscv32-unknown-linux-gnu'
+options = find_build_target GCC_VERSION, target
+
+options.tools.mkpath
+binutils options
+gcc1 options
+headers options
+kernel options
+glibc options
+gcc2 options