Replace libfdt's CMakeLists.txt with nix build

deps/libfdt/clang-no-suggest-attr-format.patch

@@ -0,0 +1,16 @@
+diff --git a/Makefile b/Makefile
+index f1f0ab3..edbcb4a 100644
+--- a/Makefile
++++ b/Makefile
+@@ -20,7 +20,10 @@ ASSUME_MASK ?= 0
+ CPPFLAGS = -I libfdt -I . -DFDT_ASSUME_MASK=$(ASSUME_MASK)
+ WARNINGS = -Wall -Wpointer-arith -Wcast-qual -Wnested-externs -Wsign-compare \
+ 	-Wstrict-prototypes -Wmissing-prototypes -Wredundant-decls -Wshadow \
+-	-Wsuggest-attribute=format -Wwrite-strings
++	-Wwrite-strings
++ifeq ($(findstring gcc,$(notdir $(CC))),gcc)
++WARNINGS += -Wsuggest-attribute=format
++endif
+ CFLAGS = -g -Os $(SHAREDLIB_CFLAGS) -Werror $(WARNINGS) $(EXTRA_CFLAGS)
+
+ BISON = bison

deps/libfdt/default.nix

@@ -0,0 +1,48 @@
+{
+  pkgs,
+  stdenv
+}:
+
+let
+  self = stdenv.mkDerivation rec {
+    pname = "libfdt";
+    version = "1.7.2";
+    src = pkgs.fetchzip {
+      url = "https://mirrors.edge.kernel.org/pub/software/utils/dtc/dtc-${version}.tar.xz";
+      hash = "sha256-KZCzrvdWd6zfQHppjyp4XzqNCfH2UnuRneu+BNIRVAY=";
+    };
+    meta.license = pkgs.lib.licenses.bsd2;
+
+    nativeBuildInputs = with pkgs.buildPackages; [
+      pkg-config flex bison
+    ];
+    outputs = [ "out" "dev" ];
+
+    patches = [
+      ./clang-no-suggest-attr-format.patch  # TODO: upstream
+    ];
+
+    buildPhase = ''
+      runHook preBuild
+      make -j"$NIX_BUILD_CORES" libfdt/libfdt.a
+      runHook postBuild
+    '';
+
+    installPhase = ''
+      runHook preInstall
+      install -D -m644 -t "$out/lib/" libfdt/libfdt.a
+      install -D -m644 -t "$dev/include/fdt" libfdt/*.h
+      runHook postInstall
+    '';
+  };
+
+  dev = pkgs.lib.getDev self;
+in
+  self.overrideAttrs (prev: {
+    passthru = {
+      include_root = "${dev}/include";
+      include      = "${dev}/include/fdt";
+      lib          = "${self}/lib";
+    };
+  })
+

overlay.nix

@@ -92,6 +92,7 @@ final: prev: {
     http-parser = self.callPackage ./deps/http-parser/default.nix { };
     s2n-tls = self.callPackage ./deps/s2n/default.nix { };
     uzlib = self.callPackage ./deps/uzlib/default.nix { };
+    libfdt = self.callPackage ./deps/libfdt/default.nix { };
 
     vmbuild = self.callPackage ./vmbuild.nix { };
 
@@ -165,6 +166,7 @@ final: prev: {
         prev.pkgsStatic.openssl
         prev.pkgsStatic.rapidjson
         #self.s2n-tls          👈 This is postponed until we can fix the s2n build.
+        self.libfdt
         self.uzlib
         self.vmbuild
       ];
@@ -209,6 +211,7 @@ final: prev: {
         inherit (self) http-parser;
         inherit (self) botan2;
         inherit (self) libfmt;
+        inherit (self) libfdt;
         #inherit (self) s2n-tls;
         inherit (self) cmake;
         inherit (self) vmbuild;