From 574d1e47ea9fa29f6a6ad3f2222d982aa48af940 Mon Sep 17 00:00:00 2001
From: pennae <github@quasiparticle.net>
Date: Fri, 10 Mar 2023 07:10:23 +0100
Subject: [PATCH 1/2] avrlibc: enable parallel builds

this cuts about 80% off the build time with no apparent negative effects.
---
 pkgs/development/misc/avr/libc/default.nix | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/pkgs/development/misc/avr/libc/default.nix b/pkgs/development/misc/avr/libc/default.nix
index ac9da31fcc0f8..9b3ac75d11046 100644
--- a/pkgs/development/misc/avr/libc/default.nix
+++ b/pkgs/development/misc/avr/libc/default.nix
@@ -15,6 +15,8 @@ stdenv.mkDerivation rec {
   stripDebugList = [ "bin" ];
   dontPatchELF = true;
 
+  enableParallelBuilding = true;
+
   passthru = {
     incdir = "/avr/include";
   };

From b2844f89d10d4a2665aed231144950c354f275a6 Mon Sep 17 00:00:00 2001
From: pennae <github@quasiparticle.net>
Date: Fri, 10 Mar 2023 07:26:28 +0100
Subject: [PATCH 2/2] avrlibc: hook up libdir for cc-wrapper

-B must be set to the root directory of avrlibc, otherwise gcc cannot
locate crt objects for some attiny devices. -L trains as set by
bintools-wrapper are not necessary with -B set correctly because gcc
takes care of that, and likewise we can drop the -B train from
cc-wrapper because the one spec is enough.
---
 pkgs/build-support/bintools-wrapper/default.nix | 6 ------
 pkgs/build-support/cc-wrapper/default.nix       | 6 ------
 pkgs/development/misc/avr/libc/default.nix      | 1 +
 3 files changed, 1 insertion(+), 12 deletions(-)

diff --git a/pkgs/build-support/bintools-wrapper/default.nix b/pkgs/build-support/bintools-wrapper/default.nix
index ccd342eaa0d19..dd6032fc52cfa 100644
--- a/pkgs/build-support/bintools-wrapper/default.nix
+++ b/pkgs/build-support/bintools-wrapper/default.nix
@@ -301,12 +301,6 @@ stdenv.mkDerivation {
       hardening_unsupported_flags+=" relro bindnow"
     ''
 
-    + optionalString (libc != null && targetPlatform.isAvr) ''
-      for isa in avr5 avr3 avr4 avr6 avr25 avr31 avr35 avr51 avrxmega2 avrxmega4 avrxmega5 avrxmega6 avrxmega7 tiny-stack; do
-        echo "-L${getLib libc}/avr/lib/$isa" >> $out/nix-support/libc-cflags
-      done
-    ''
-
     + optionalString stdenv.targetPlatform.isDarwin ''
       echo "-arch ${targetPlatform.darwinArch}" >> $out/nix-support/libc-ldflags
     ''
diff --git a/pkgs/build-support/cc-wrapper/default.nix b/pkgs/build-support/cc-wrapper/default.nix
index 8ac11436c5f7b..539c29a0a7743 100644
--- a/pkgs/build-support/cc-wrapper/default.nix
+++ b/pkgs/build-support/cc-wrapper/default.nix
@@ -649,12 +649,6 @@ stdenv.mkDerivation {
       hardening_unsupported_flags+=" stackprotector"
     ''
 
-    + optionalString (libc != null && targetPlatform.isAvr) ''
-      for isa in avr5 avr3 avr4 avr6 avr25 avr31 avr35 avr51 avrxmega2 avrxmega4 avrxmega5 avrxmega6 avrxmega7 tiny-stack; do
-        echo "-B${getLib libc}/avr/lib/$isa" >> $out/nix-support/libc-crt1-cflags
-      done
-    ''
-
     + optionalString stdenv.targetPlatform.isDarwin ''
         echo "-arch ${targetPlatform.darwinArch}" >> $out/nix-support/cc-cflags
     ''
diff --git a/pkgs/development/misc/avr/libc/default.nix b/pkgs/development/misc/avr/libc/default.nix
index 9b3ac75d11046..d7e9f0efe9992 100644
--- a/pkgs/development/misc/avr/libc/default.nix
+++ b/pkgs/development/misc/avr/libc/default.nix
@@ -19,6 +19,7 @@ stdenv.mkDerivation rec {
 
   passthru = {
     incdir = "/avr/include";
+    libdir = "/avr/lib";
   };
 
   meta = with lib; {