From 5ea6bb839e7bd773f6c995ca6018b68cb8ace7aa Mon Sep 17 00:00:00 2001
From: John Ericson <John.Ericson@Obsidian.Systems>
Date: Wed, 29 Sep 2021 21:18:21 -0400
Subject: [PATCH 1/2] newlib: Add parameter for "nano" variant

---
 pkgs/development/misc/newlib/default.nix | 22 +++++++++++++++++++---
 1 file changed, 19 insertions(+), 3 deletions(-)

diff --git a/pkgs/development/misc/newlib/default.nix b/pkgs/development/misc/newlib/default.nix
index 870aa068afe8..60ad50a8e4f7 100644
--- a/pkgs/development/misc/newlib/default.nix
+++ b/pkgs/development/misc/newlib/default.nix
@@ -1,4 +1,9 @@
-{ stdenv, fetchurl, buildPackages }:
+{ stdenv, fetchurl, buildPackages
+, # "newlib-nano" is what the official ARM embedded toolchain calls this build
+  # configuration that prioritizes low space usage. We include it as a preset
+  # for embedded projects striving for a similar configuration.
+  nanoizeNewlib ? false
+}:
 
 stdenv.mkDerivation rec {
   pname = "newlib";
@@ -22,10 +27,21 @@ stdenv.mkDerivation rec {
 
     "--disable-newlib-supplied-syscalls"
     "--disable-nls"
+    "--enable-newlib-retargetable-locking"
+  ] ++ (if !nanoizeNewlib then [
     "--enable-newlib-io-long-long"
     "--enable-newlib-register-fini"
-    "--enable-newlib-retargetable-locking"
-  ];
+  ] else [
+    "--enable-newlib-reent-small"
+    "--disable-newlib-fvwrite-in-streamio"
+    "--disable-newlib-fseek-optimization"
+    "--disable-newlib-wide-orient"
+    "--enable-newlib-nano-malloc"
+    "--disable-newlib-unbuf-stream-opt"
+    "--enable-lite-exit"
+    "--enable-newlib-global-atexit"
+    "--enable-newlib-nano-formatted-io"
+  ]);
 
   dontDisableStatic = true;
 

From e3ff6189f6aa641e108876de32ad83a542259b60 Mon Sep 17 00:00:00 2001
From: John Ericson <John.Ericson@Obsidian.Systems>
Date: Thu, 30 Sep 2021 20:49:31 -0400
Subject: [PATCH 2/2] newlib-nano: Init

This ensures CI tests the nano variant. It also makes it easier to use
with `libc = "newlib-nano";` in a platform description.
---
 pkgs/top-level/all-packages.nix | 11 ++++++++++-
 1 file changed, 10 insertions(+), 1 deletion(-)

diff --git a/pkgs/top-level/all-packages.nix b/pkgs/top-level/all-packages.nix
index e95132f3699e..9bbffa3d2930 100644
--- a/pkgs/top-level/all-packages.nix
+++ b/pkgs/top-level/all-packages.nix
@@ -15985,6 +15985,7 @@ with pkgs;
     else if name == "newlib" && stdenv.targetPlatform.isVc4 then targetPackages.vc4-newlib or vc4-newlib
     else if name == "newlib" && stdenv.targetPlatform.isOr1k then targetPackages.or1k-newlib or or1k-newlib
     else if name == "newlib" then targetPackages.newlibCross or newlibCross
+    else if name == "newlib-nano" then targetPackages.newlib-nanoCross or newlib-nanoCross
     else if name == "musl" then targetPackages.muslCross or muslCross
     else if name == "msvcrt" then targetPackages.windows.mingw_w64 or windows.mingw_w64
     else if name == "libSystem" then
@@ -32840,7 +32841,15 @@ with pkgs;
   newlib = callPackage ../development/misc/newlib { };
   newlibCross = callPackage ../development/misc/newlib {
     stdenv = crossLibcStdenv;
-    };
+  };
+
+  newlib-nano = callPackage ../development/misc/newlib {
+    nanoizeNewlib = true;
+  };
+  newlib-nanoCross = callPackage ../development/misc/newlib {
+    nanoizeNewlib = true;
+    stdenv = crossLibcStdenv;
+  };
 
   omnisharp-roslyn = callPackage ../development/tools/omnisharp-roslyn { dotnet-sdk = dotnet-sdk_5; };