diff --git a/default.nix b/default.nix
index faf227ba..af343cd3 100644
--- a/default.nix
+++ b/default.nix
@@ -2,6 +2,7 @@ let
   zynq-rs = (import ./zynq-rs.nix);
   pkgs = import <nixpkgs> { overlays = [ (import "${zynq-rs}/nix/mozilla-overlay.nix") ]; };
   rustPlatform = (import "${zynq-rs}/nix/rust-platform.nix" { inherit pkgs; });
+  cargo-xbuild = (import zynq-rs).cargo-xbuild;
   zc706-szl = (import zynq-rs).zc706-szl;
   zc706-fsbl = import "${zynq-rs}/nix/fsbl.nix" { inherit pkgs; };
   mkbootimage = import "${zynq-rs}/nix/mkbootimage.nix" { inherit pkgs; };
@@ -13,12 +14,12 @@ let
       version = "0.1.0";
 
       src = ./src;
-      cargoSha256 = "152k0jvx02a66dafyc25pz60wlg7i3kln9hh7nwl2wcanmqzzkbw";
+      cargoSha256 = "1kkh2fscdy2dz5bfbk36hrk6xd4dizbkfvqfihf15jfr5i94gi4x";
 
       nativeBuildInputs = [
         pkgs.gnumake
         (pkgs.python3.withPackages(ps: (with artiqpkgs; [ migen migen-axi misoc artiq ])))
-        pkgs.cargo-xbuild
+        cargo-xbuild
         pkgs.llvmPackages_9.llvm
         pkgs.llvmPackages_9.clang-unwrapped
       ];
diff --git a/shell.nix b/shell.nix
index 233f6eec..a9d0080b 100644
--- a/shell.nix
+++ b/shell.nix
@@ -17,7 +17,7 @@ in
       pkgs.llvmPackages_9.llvm
       pkgs.llvmPackages_9.clang-unwrapped
       pkgs.cacert
-      (cargo-xbuild.overrideAttrs(oa: { patches = oa.patches ++ [ ./xbuild_override_compiler_builtins.patch ]; } ))
+      cargo-xbuild
 
       pkgs.openocd
       pkgs.openssh pkgs.rsync
diff --git a/src/Cargo.lock b/src/Cargo.lock
index 64f03adb..57ddfcd9 100644
--- a/src/Cargo.lock
+++ b/src/Cargo.lock
@@ -13,15 +13,15 @@ dependencies = [
 
 [[package]]
 name = "autocfg"
-version = "1.0.0"
+version = "1.0.1"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "f8aac770f1885fd7e387acedd76065302551364496e46b3dd00860b2f8359b9d"
+checksum = "cdb031dd78e28731d87d56cc8ffef4a8f36ca26c38fe2de700543e627f8a464a"
 
 [[package]]
 name = "bit_field"
-version = "0.10.0"
+version = "0.10.1"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "a165d606cf084741d4ac3a28fb6e9b1eb0bd31f6cd999098cfddb0b2ab381dc0"
+checksum = "dcb6dd1c2376d2e096796e234a70e17e94cc2d5d54ff8ce42b28cef1d0d359a4"
 
 [[package]]
 name = "bitflags"
@@ -37,9 +37,9 @@ checksum = "08c48aae112d48ed9f069b33538ea9e3e90aa263cfa3d1c24309612b1f7472de"
 
 [[package]]
 name = "cc"
-version = "1.0.58"
+version = "1.0.61"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "f9a06fb2e53271d7c279ec1efea6ab691c35a2ae67ec0d91d7acec0caf13b518"
+checksum = "ed67cbde08356238e75fc4656be4749481eeffb09e19f320a25237d5221c985d"
 
 [[package]]
 name = "cfg-if"
@@ -49,11 +49,9 @@ checksum = "4785bdd1c96b2a846b2bd7cc02e86b6b3dbf14e7e53446c4f54c92a361040822"
 
 [[package]]
 name = "compiler_builtins"
-version = "0.1.33"
-source = "git+https://git.m-labs.hk/M-Labs/compiler-builtins-zynq.git#62a622ba62c671aaadce7c108854551086df41f8"
-dependencies = [
- "cc",
-]
+version = "0.1.35"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "e3fcd8aba10d17504c87ef12d4f62ef404c6a4703d16682a9eb5543e6cf24455"
 
 [[package]]
 name = "core_io"
@@ -111,9 +109,9 @@ dependencies = [
 
 [[package]]
 name = "futures"
-version = "0.3.5"
+version = "0.3.6"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "1e05b85ec287aac0dc34db7d4a569323df697f9c55b99b15d6b4ef8cde49f613"
+checksum = "5d8e3078b7b2a8a671cb7a3d17b4760e4181ea243227776ba83fd043b4ca034e"
 dependencies = [
  "futures-channel",
  "futures-core",
@@ -125,9 +123,9 @@ dependencies = [
 
 [[package]]
 name = "futures-channel"
-version = "0.3.5"
+version = "0.3.6"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "f366ad74c28cca6ba456d95e6422883cfb4b252a83bed929c83abfdbbf2967d5"
+checksum = "a7a4d35f7401e948629c9c3d6638fb9bf94e0b2121e96c3b428cc4e631f3eb74"
 dependencies = [
  "futures-core",
  "futures-sink",
@@ -135,21 +133,21 @@ dependencies = [
 
 [[package]]
 name = "futures-core"
-version = "0.3.5"
+version = "0.3.6"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "59f5fff90fd5d971f936ad674802482ba441b6f09ba5e15fd8b39145582ca399"
+checksum = "d674eaa0056896d5ada519900dbf97ead2e46a7b6621e8160d79e2f2e1e2784b"
 
 [[package]]
 name = "futures-io"
-version = "0.3.5"
+version = "0.3.6"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "de27142b013a8e869c14957e6d2edeef89e97c289e69d042ee3a49acd8b51789"
+checksum = "5fc94b64bb39543b4e432f1790b6bf18e3ee3b74653c5449f63310e9a74b123c"
 
 [[package]]
 name = "futures-macro"
-version = "0.3.5"
+version = "0.3.6"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "d0b5a30a4328ab5473878237c447333c093297bded83a4983d10f4deea240d39"
+checksum = "f57ed14da4603b2554682e9f2ff3c65d7567b53188db96cb71538217fc64581b"
 dependencies = [
  "proc-macro-hack",
  "proc-macro2",
@@ -159,21 +157,21 @@ dependencies = [
 
 [[package]]
 name = "futures-sink"
-version = "0.3.5"
+version = "0.3.6"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "3f2032893cb734c7a05d85ce0cc8b8c4075278e93b24b66f9de99d6eb0fa8acc"
+checksum = "0d8764258ed64ebc5d9ed185cf86a95db5cac810269c5d20ececb32e0088abbd"
 
 [[package]]
 name = "futures-task"
-version = "0.3.5"
+version = "0.3.6"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "bdb66b5f09e22019b1ab0830f7785bcea8e7a42148683f99214f73f8ec21a626"
+checksum = "4dd26820a9f3637f1302da8bceba3ff33adbe53464b54ca24d4e2d4f1db30f94"
 
 [[package]]
 name = "futures-util"
-version = "0.3.5"
+version = "0.3.6"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "8764574ff08b701a084482c3c7031349104b07ac897393010494beaa18ce32c6"
+checksum = "8a894a0acddba51a2d49a6f4263b1e64b8c579ece8af50fa86503d52cd1eea34"
 dependencies = [
  "futures-core",
  "futures-macro",
@@ -321,9 +319,9 @@ checksum = "546c37ac5d9e56f55e73b677106873d9d9f5190605e41a856503623648488cae"
 
 [[package]]
 name = "num-derive"
-version = "0.3.1"
+version = "0.3.2"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "e0396233fb2d5b0ae3f05ff6aba9a09185f7f6e70f87fb01147d545f85364665"
+checksum = "6f09b9841adb6b5e1f89ef7087ea636e0fd94b2851f887c1e3eb5d5f8228fab3"
 dependencies = [
  "proc-macro2",
  "quote",
@@ -341,18 +339,18 @@ dependencies = [
 
 [[package]]
 name = "pin-project"
-version = "0.4.23"
+version = "0.4.27"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "ca4433fff2ae79342e497d9f8ee990d174071408f28f726d6d83af93e58e48aa"
+checksum = "2ffbc8e94b38ea3d2d8ba92aea2983b503cd75d0888d75b86bb37970b5698e15"
 dependencies = [
  "pin-project-internal",
 ]
 
 [[package]]
 name = "pin-project-internal"
-version = "0.4.23"
+version = "0.4.27"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "2c0e815c3ee9a031fdf5af21c10aa17c573c9c6a566328d99e3936c34e36461f"
+checksum = "65ad2ae56b6abe3a1ee25f15ee605bacadb9a764edaba9c2bf4103800d4a1895"
 dependencies = [
  "proc-macro2",
  "quote",
@@ -379,9 +377,9 @@ checksum = "eba180dafb9038b050a4c280019bbedf9f2467b61e5d892dcad585bb57aadc5a"
 
 [[package]]
 name = "proc-macro2"
-version = "1.0.19"
+version = "1.0.24"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "04f5f085b5d71e2188cb8271e5da0161ad52c3f227a661a3c135fdf28e258b12"
+checksum = "1e0704ee1a7e00d7bb417d0770ea303c1bccbabf0ef1667dae92b5967f5f8a71"
 dependencies = [
  "unicode-xid",
 ]
@@ -444,9 +442,9 @@ dependencies = [
 
 [[package]]
 name = "syn"
-version = "1.0.38"
+version = "1.0.44"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "e69abc24912995b3038597a7a593be5053eb0fb44f3cc5beec0deb421790c1f4"
+checksum = "e03e57e4fcbfe7749842d53e24ccb9aa12b7252dbe5e91d2acad31834c8b8fdd"
 dependencies = [
  "proc-macro2",
  "quote",
diff --git a/src/Cargo.toml b/src/Cargo.toml
index 4bd1b9d3..18045186 100644
--- a/src/Cargo.toml
+++ b/src/Cargo.toml
@@ -16,4 +16,3 @@ lto = true
 
 [patch.crates-io]
 core_io = { git = "https://git.m-labs.hk/M-Labs/zynq-rs.git" }
-compiler_builtins = { git = "https://git.m-labs.hk/M-Labs/compiler-builtins-zynq.git"}
diff --git a/xbuild_override_compiler_builtins.patch b/xbuild_override_compiler_builtins.patch
deleted file mode 100644
index 02aba14a..00000000
--- a/xbuild_override_compiler_builtins.patch
+++ /dev/null
@@ -1,13 +0,0 @@
-diff --git a/src/sysroot.rs b/src/sysroot.rs
-index 1f3c8d1..e5615ee 100644
---- a/src/sysroot.rs
-+++ b/src/sysroot.rs
-@@ -163,7 +163,7 @@ version = "0.0.0"
- edition = "2018"
- 
- [dependencies.compiler_builtins]
--version = "0.1.0"
-+git = "https://git.m-labs.hk/M-Labs/compiler-builtins-zynq.git"
- "#;
- 
-     let mut stoml = TOML.to_owned();