seL4 Nix expression for Raspberry Pi 3 (may be broken!)

seL4.nix

with rec {
  pkgs = import <nixpkgs> {};
  inherit (pkgs) stdenv gcc-arm-embedded libxml2 ncurses python27Packages;
  inherit (pkgs) which fetchFromGitHub;
};

stdenv.mkDerivation rec {
  name = "seL4";

  src = fetchFromGitHub {
    repo   = "seL4";
    owner  = "seL4";
    rev    = "93f59d4932c5370dfbb5ed38689097813abec08b";
    sha256 = "0hkkkjxmb49v8hnjk83l60s0jvchw27sfi5w9haxl6jwsb3v8fi6";
  };

  patches = [ ./seL4.patch ];

  buildInputs = [
    gcc-arm-embedded
    which
    libxml2
    ncurses.out
    ncurses.dev
    python27Packages.python
    python27Packages.six
    python27Packages.tempita
  ];

  buildPhase = ''
      TOOLPREFIX=arm-none-eabi- ARCH=arm PLAT=bcm2837 ARMV=armv7-a CPU=cortex-a53 make
  '';

  installPhase = ''
      mkdir -p "$out/"
      cp kernel.elf       "$out/"
      cp kernel.elf.strip "$out/"
  '';
}

seL4.patch

diff --git a/Makefile b/Makefile
index 79f5bcb..0e95066 100644
--- a/Makefile
+++ b/Makefile
@@ -343,6 +343,9 @@ ifeq ($(PLAT),allwinnerA20)
 DEFINES += -DALLWINNERA20
 endif
 endif # SEL4_ARCH=aarch32
+ifeq (${CPU},cortex-a53)
+DEFINES += -DARM_CORTEX_A53
+endif
 ifeq (${CPU},cortex-a57)
 DEFINES += -DARM_CORTEX_A57
 endif
diff --git a/include/plat/bcm2837/autoconf.h b/include/plat/bcm2837/autoconf.h
new file mode 100644
index 0000000..e69de29
diff --git a/tools/changed.sh b/tools/changed.sh
index cd3f5f1..e8b9a33 100755
--- a/tools/changed.sh
+++ b/tools/changed.sh
@@ -1,4 +1,4 @@
-#!/bin/bash
+#!/usr/bin/env bash
 #
 # Copyright 2014, NICTA
 #
diff --git a/tools/cpp_gen.sh b/tools/cpp_gen.sh
index cb26b29..60f229f 100755
--- a/tools/cpp_gen.sh
+++ b/tools/cpp_gen.sh
@@ -1,4 +1,4 @@
-#!/bin/bash
+#!/usr/bin/env bash
 #
 # Copyright 2014, NICTA
 #
diff --git a/tools/xmllint.sh b/tools/xmllint.sh
index 32de8b6..f4b3df0 100755
--- a/tools/xmllint.sh
+++ b/tools/xmllint.sh
@@ -1,4 +1,4 @@
-#!/bin/bash
+#!/usr/bin/env bash
 #
 # Copyright 2014, NICTA
 #