diff --git a/.gitmodules b/.gitmodules
index 9191108..63c4d60 100644
--- a/.gitmodules
+++ b/.gitmodules
@@ -1,6 +1,6 @@
 [submodule "hal/stm32l4"]
 	path = hal/stm32l4
-	url = https://github.com/OsirisRTOS/stm32l4-hal.git
+	url = git@github.com:OsirisRTOS/stm32l4-hal.git
 [submodule "kernel"]
 	path = kernel
-	url = https://github.com/OsirisRTOS/kernel.git
+	url = git@github.com:OsirisRTOS/kernel.git
diff --git a/shell.nix b/shell.nix
index 7039450..a3ecfd9 100644
--- a/shell.nix
+++ b/shell.nix
@@ -2,6 +2,7 @@ with import <nixpkgs> { };
 
 mkShell {
   nativeBuildInputs = [
+    rustup
     direnv
     gcc-arm-embedded
     cmake
@@ -54,5 +55,6 @@ mkShell {
     cd ..
   fi
   export PATH=$(pwd)/qemu/build:$PATH
+  rustup target add thumbv7em-none-eabi
   '';
 }