udpate docs (#4348)

Author: czoido

examples/cross_build/toolchain_packages.rst

@@ -52,7 +52,7 @@ Let's check the recipe and go through the most relevant parts:
 
     import os
     from conan import ConanFile
-    from conan.tools.files import get, copy, download
+    from conan.tools.files import get, copy, save
     from conan.errors import ConanInvalidConfiguration
     from conan.tools.scm import Version
 
@@ -85,22 +85,27 @@ Let's check the recipe and go through the most relevant parts:
             valid_archs = self._archs32() + self._archs64()
             if self.settings_target.os != "Linux" or self.settings_target.arch not in valid_archs:
                 raise ConanInvalidConfiguration(f"This toolchain only supports building for Linux-{valid_archs.join(',')}. "
-                                            f"{self.settings_target.os}-{self.settings_target.arch} is not supported.")
+                                               f"{self.settings_target.os}-{self.settings_target.arch} is not supported.")
 
             if self.settings_target.compiler != "gcc":
                 raise ConanInvalidConfiguration(f"The compiler is set to '{self.settings_target.compiler}', but this "
                                                 "toolchain only supports building with gcc.")
 
             if Version(self.settings_target.compiler.version) >= Version("14") or Version(self.settings_target.compiler.version) < Version("13"):
                 raise ConanInvalidConfiguration(f"Invalid gcc version '{self.settings_target.compiler.version}'. "
-                                                    "Only 13.X versions are supported for the compiler.")
+                                                "Only 13.X versions are supported for the compiler.")
 
         def source(self):
-            download(self, "https://developer.arm.com/GetEula?Id=37988a7c-c40e-4b78-9fd1-62c20b507aa8", "LICENSE", verify=False)
+            # The ARM toolchain is distributed under GPL-3.0-only license
+            # Reference: https://developer.arm.com/downloads/-/arm-gnu-toolchain-downloads
+            save(self, "LICENSE", "ARM GNU Toolchain\n"
+                 "License: GNU General Public License v3.0 (GPL-3.0-only)\n"
+                 "https://www.gnu.org/licenses/gpl-3.0.html\n\n"
+                 "EULA: https://developer.arm.com/GetEula?Id=37988a7c-c40e-4b78-9fd1-62c20b507aa8\n")
 
         def build(self):
             toolchain, sha = self._get_toolchain(self.settings_target.arch)
-            get(self, f"https://developer.arm.com/-/media/Files/downloads/gnu/13.2.rel1/binrel/arm-gnu-toolchain-13.2.rel1-x86_64-{toolchain}.tar.xz",
+            get(self, f"https://armkeil.blob.core.windows.net/developer/Files/downloads/gnu/13.2.rel1/binrel/arm-gnu-toolchain-13.2.rel1-x86_64-{toolchain}.tar.xz",
                 sha256=sha, strip_root=True)            
 
         def package_id(self):
@@ -260,24 +265,30 @@ Downloading the binaries for the toolchain and packaging it
                     "12fcdf13a7430655229b20438a49e8566e26551ba08759922cdaf4695b0d4e23")
 
     def source(self):
-        download(self, "https://developer.arm.com/GetEula?Id=37988a7c-c40e-4b78-9fd1-62c20b507aa8", "LICENSE", verify=False)
+        # The ARM toolchain is distributed under GPL-3.0-only license
+        # Reference: https://developer.arm.com/downloads/-/arm-gnu-toolchain-downloads
+        save(self, "LICENSE", "ARM GNU Toolchain\n"
+             "License: GNU General Public License v3.0 (GPL-3.0-only)\n"
+             "https://www.gnu.org/licenses/gpl-3.0.html\n\n"
+             "EULA: https://developer.arm.com/GetEula?Id=37988a7c-c40e-4b78-9fd1-62c20b507aa8\n")
 
     def build(self):
         toolchain, sha = self._get_toolchain(self.settings_target.arch)
-        get(self, f"https://developer.arm.com/-/media/Files/downloads/gnu/13.2.rel1/binrel/arm-gnu-toolchain-13.2.rel1-x86_64-{toolchain}.tar.xz",
+        get(self, f"https://armkeil.blob.core.windows.net/developer/Files/downloads/gnu/13.2.rel1/binrel/arm-gnu-toolchain-13.2.rel1-x86_64-{toolchain}.tar.xz",
             sha256=sha, strip_root=True)            
 
     def package(self):
         toolchain, _ = self._get_toolchain(self.settings_target.arch)
         dirs_to_copy = [toolchain, "bin", "include", "lib", "libexec"]
         for dir_name in dirs_to_copy:
             copy(self, pattern=f"{dir_name}/*", src=self.build_folder, dst=self.package_folder, keep_path=True)
-        copy(self, "LICENSE", src=self.build_folder, dst=os.path.join(self.package_folder, "licenses"), keep_path=False)
+        copy(self, "LICENSE", src=self.source_folder, dst=os.path.join(self.package_folder, "licenses"), keep_path=False)
 
     ...
 
-The `source()` method is used to download the recipe license, as it's found on the ARM
-toolchains' download page. However, this is the only action performed there. The actual
+The `source()` method is used to download or reference the recipe license. In
+this case, we reference the ARM toolchain's GPL-3.0 license and EULA. However,
+this is the only action performed there. The actual
 toolchain binaries are fetched in the `build()` method. This approach is necessary because
 the toolchain package is designed to support both 32-bit and 64-bit architectures,
 requiring us to download two distinct sets of toolchain binaries. Which binary the package