U-Boot: Add 64-bit Raspberry Pi 3 build

And rename the old ubootRaspberryPi3 to ubootRaspberryPi3_32bit.

nixos/modules/installer/cd-dvd/sd-image-armv7l-multiplatform.nix

@@ -46,7 +46,7 @@ in
           cp ${pkgs.raspberrypifw}/share/raspberrypi/boot/$f boot/
         done
         cp ${pkgs.ubootRaspberryPi2}/u-boot.bin boot/u-boot-rpi2.bin
-        cp ${pkgs.ubootRaspberryPi3}/u-boot.bin boot/u-boot-rpi3.bin
+        cp ${pkgs.ubootRaspberryPi3_32bit}/u-boot.bin boot/u-boot-rpi3.bin
         cp ${configTxt} boot/config.txt
         ${extlinux-conf-builder} -t 3 -c ${config.system.build.toplevel} -d ./boot
       '';

pkgs/misc/uboot/default.nix

@@ -100,12 +100,18 @@ in rec {
     filesToInstall = ["u-boot.bin"];
   };
 
-  ubootRaspberryPi3 = buildUBoot rec {
+  ubootRaspberryPi3_32bit = buildUBoot rec {
     defconfig = "rpi_3_32b_defconfig";
     targetPlatforms = ["armv7l-linux"];
     filesToInstall = ["u-boot.bin"];
   };
 
+  ubootRaspberryPi3_64bit = buildUBoot rec {
+    defconfig = "rpi_3_defconfig";
+    targetPlatforms = ["aarch64-linux"];
+    filesToInstall = ["u-boot.bin"];
+  };
+
   ubootWandboard = buildUBoot rec {
     defconfig = "wandboard_defconfig";
     targetPlatforms = ["armv7l-linux"];

pkgs/top-level/all-packages.nix

@@ -11813,7 +11813,8 @@ with pkgs;
     ubootPcduino3Nano
     ubootRaspberryPi
     ubootRaspberryPi2
-    ubootRaspberryPi3
+    ubootRaspberryPi3_32bit
+    ubootRaspberryPi3_64bit
     ubootWandboard
     ;