Add RISC-V embedded crossSystems

lib/systems/doubles.nix

@@ -26,7 +26,7 @@ let
 
     "riscv32-linux" "riscv64-linux"
 
-    "aarch64-none" "avr-none" "arm-none" "i686-none" "x86_64-none" "powerpc-none" "msp430-none"
+    "aarch64-none" "avr-none" "arm-none" "i686-none" "x86_64-none" "powerpc-none" "msp430-none" "riscv64-none" "riscv32-none"
   ];
 
   allParsed = map parse.mkSystemFromString all;

lib/systems/examples.nix

@@ -97,6 +97,18 @@ rec {
   riscv64 = riscv "64";
   riscv32 = riscv "32";
 
+  riscv64-embedded = {
+    config = "riscv64-none-elf";
+    libc = "newlib";
+    platform = platforms.riscv-multiplatform "64";
+  };
+
+  riscv32-embedded = {
+    config = "riscv32-none-elf";
+    libc = "newlib";
+    platform = platforms.riscv-multiplatform "32";
+  };
+
   msp430 = {
     config = "msp430-elf";
     libc = "newlib";