lib.systems.examples: use four component triples for embedded

Thanks to a [change in gnu-config] we no longer have to rely on
gnu-config interpreting `none` as a vendor and nixpkgs as a kernel.
Instead we can specify a four component triple that corresponds to how
nixpkgs interprets the shortened one because gnu-config now accepts
them (the long form at least).

As a result, we also need to make sure that an up to date gnu-config is
used for the affected platforms (everything with kernel none).

Reference #165836.

[change in gnu-config]: https://git.savannah.gnu.org/cgit/config.git/commit/?id=998ba1414387b4ce1a519be234e1609bc7912e0c

lib/systems/examples.nix

@@ -124,22 +124,22 @@ rec {
   riscv32 = riscv "32";
 
   riscv64-embedded = {
-    config = "riscv64-none-elf";
+    config = "riscv64-unknown-none-elf";
     libc = "newlib";
   };
 
   riscv32-embedded = {
-    config = "riscv32-none-elf";
+    config = "riscv32-unknown-none-elf";
     libc = "newlib";
   };
 
   mips64-embedded = {
-    config = "mips64-none-elf";
+    config = "mips64-unknown-none-elf";
     libc = "newlib";
   };
 
   mips-embedded = {
-    config = "mips-none-elf";
+    config = "mips-unknown-none-elf";
     libc = "newlib";
   };
 
@@ -153,7 +153,7 @@ rec {
   };
 
   rx-embedded = {
-    config = "rx-none-elf";
+    config = "rx-unknown-none-elf";
     libc = "newlib";
   };
 
@@ -189,11 +189,11 @@ rec {
   };
 
   arm-embedded = {
-    config = "arm-none-eabi";
+    config = "arm-unknown-none-eabi";
     libc = "newlib";
   };
   armhf-embedded = {
-    config = "arm-none-eabihf";
+    config = "arm-unknown-none-eabihf";
     libc = "newlib";
     # GCC8+ does not build without this
     # (https://www.mail-archive.com/gcc-bugs@gcc.gnu.org/msg552339.html):
@@ -204,22 +204,22 @@ rec {
   };
 
   aarch64-embedded = {
-    config = "aarch64-none-elf";
+    config = "aarch64-unknown-none-elf";
     libc = "newlib";
   };
 
   aarch64be-embedded = {
-    config = "aarch64_be-none-elf";
+    config = "aarch64_be-unknown-none-elf";
     libc = "newlib";
   };
 
   ppc-embedded = {
-    config = "powerpc-none-eabi";
+    config = "powerpc-unknown-none-eabi";
     libc = "newlib";
   };
 
   ppcle-embedded = {
-    config = "powerpcle-none-eabi";
+    config = "powerpcle-unknown-none-eabi";
     libc = "newlib";
   };
 

pkgs/stdenv/cross/default.nix

@@ -80,7 +80,7 @@ in lib.init bootStages ++ [
              (hostPlatform.isLinux && !buildPlatform.isLinux)
              [ buildPackages.patchelf ]
         ++ lib.optional
-             (let f = p: !p.isx86 || builtins.elem p.libc [ "musl" "wasilibc" "relibc" ] || p.isiOS || p.isGenode;
+             (let f = p: !p.isx86 || builtins.elem p.libc [ "musl" "wasilibc" "relibc" ] || p.isiOS || p.isGenode || p.isNone;
                in f hostPlatform && !(f buildPlatform) )
              buildPackages.updateAutotoolsGnuConfigScriptsHook
         ;