diff --git a/overlay.nix b/overlay.nix
index 176d4c3..41d2fc3 100644
--- a/overlay.nix
+++ b/overlay.nix
@@ -12,6 +12,11 @@ in
     externalFirst = true;
   };
 
+  # Image to be written to SD to install to SPI.
+  pinebookpro-firmware-installer = callPackage ./u-boot/spi-installer.nix {
+    uboot = final.uBootPinebookPro;
+  };           
+
   # The unqualified kernel attr is deprecated.
   linux_pinebookpro = throw "The linux_pinebookpro attribute has been replaced by linux_pinebookpro_latest.";
   linuxPackages_pinebookpro = throw "The linuxPackages_pinebookpro attribute has been replaced by linuxPackages_pinebookpro_latest.";
diff --git a/u-boot/spi-installer.nix b/u-boot/spi-installer.nix
new file mode 100644
index 0000000..a21e330
--- /dev/null
+++ b/u-boot/spi-installer.nix
@@ -0,0 +1,107 @@
+{ pkgs
+, e2fsprogs
+, runCommandNoCC
+, uboot
+, utillinux
+, ubootTools
+}:
+
+let
+  board = "pinebook-pro-rk3399";
+
+  flashscript = pkgs.writeText "${board}-flash.cmd" ''
+    echo
+    echo
+    echo ${board} firmware installer
+    echo
+    echo
+
+    if load ''${devtype} ''${devnum}:''${bootpart} ''${kernel_addr_r} ''${board_name}.spiflash.bin; then
+      sf probe
+      sf erase 0 +$filesize
+      sf write $kernel_addr_r 0 $filesize
+      echo "Flashing seems to have been successful! Resetting in 5 seconds"
+      sleep 5
+      reset
+    fi
+
+  '';
+
+  bootcmd = pkgs.writeText "${board}-boot.cmd" ''
+    setenv bootmenu_0 'Flash firmware to SPI=setenv script flash.scr; run boot_a_script'
+    setenv bootmenu_1 'Completely erase SPI=sf probe; echo "Currently erasing..."; sf erase 0 +1000000; echo "Done!"; sleep 5; bootmenu -1'
+    setenv bootmenu_2 'Reboot=reset'
+    setenv bootmenu_3
+    bootmenu -1
+  '';
+
+  mkScript = file: runCommandNoCC "${board}-boot.scr" {
+    nativeBuildInputs = [
+      ubootTools
+    ];
+  } ''
+    mkimage -C none -A arm64 -T script -d ${file} $out
+  '';
+
+  rootfsImage = runCommandNoCC "u-boot-installer-fs.img" {
+    inherit board;
+    size = "8"; # in MiB
+    nativeBuildInputs = [
+      e2fsprogs.bin
+      utillinux
+    ];
+    volumeLabel = "FIRMWARE_INSTALL";
+    uuid = "666efd84-5c25-48ec-af06-e9dadbaa830f";
+  } ''
+    img="$out"
+    (PS4=" $ "; set -x
+
+    fallocate -l "$size"M $img
+
+    mkdir -p files
+    (cd ./files
+    cp -v ${mkScript bootcmd} ./boot.scr
+    cp -v ${mkScript flashscript} ./flash.scr
+    cp -v ${uboot}/u-boot.spiflash.bin ./"$board".spiflash.bin
+    )
+
+    mkfs.ext4 -L $volumeLabel -U $uuid -d ./files $img
+    )
+  '';
+in
+
+runCommandNoCC "u-boot-installer" {
+  nativeBuildInputs = [
+    utillinux
+  ];
+  # -r--r--r-- 1 root root 1012K Dec 31  1969 u-boot.itb
+  # Flashed at exactly 8MiB in
+  gapSize = "10"; # in MiB
+} ''
+(PS4=" $ "; set -x
+mkdir -p $out
+
+img=$out/firmware-installer-image.img
+
+# Create the image file sized to fit the gap and /, plus slack.
+rootSizeBlocks=$(du -B 512 --apparent-size ${rootfsImage} | awk '{ print $1 }')
+gapSizeBlocks=$(($gapSize * 1024 * 1024 / 512))
+imageSize=$((rootSizeBlocks * 512 + gapSizeBlocks * 512))
+truncate -s $imageSize $img
+
+# type=b is 'W95 FAT32', type=83 is 'Linux'.
+# The "bootable" partition is where u-boot will look file for the bootloader
+# information (dtbs, extlinux.conf file).
+sfdisk $img <<EOF
+    label: dos
+
+    start=$((gapSize))M, type=83, bootable
+EOF
+
+eval $(partx $img -o START,SECTORS --nr 1 --pairs)
+dd conv=notrunc if=${rootfsImage} of=$img seek=$START count=$SECTORS
+
+dd if=${uboot}/idbloader.img of=$img bs=512 seek=64 conv=notrunc
+dd if=${uboot}/u-boot.itb of=$img bs=512 seek=16384 conv=notrunc
+)
+''