diff --git a/docs/files/software/boot_spi_en.cmd b/docs/files/software/boot_spi_en.cmd
new file mode 100644
index 0000000..8d2c5ed
--- /dev/null
+++ b/docs/files/software/boot_spi_en.cmd
@@ -0,0 +1,47 @@
+# DO NOT EDIT THIS FILE
+#
+# Please edit /boot/armbianEnv.txt to set supported parameters
+#
+
+# default values
+setenv rootdev "/dev/mmcblk0p1"
+setenv rootfstype "ext4"
+setenv verbosity "1"
+setenv prefix "/boot/"
+setenv boot_interface "mmc"
+setenv ethaddr "00:50:43:84:fb:2f"
+setenv eth1addr "00:50:43:25:fb:84"
+
+# fdtfile should come from compile-time u-boot patches
+if test -z "${fdtfile}"; then
+	setenv fdtfile "armada-388-helios4.dtb"
+fi
+
+echo "Boot script loaded from ${boot_interface}"
+
+if load ${boot_interface} 0:1 ${loadaddr} ${prefix}armbianEnv.txt; then
+	env import -t ${loadaddr} ${filesize}
+fi
+
+setenv bootargs "console=ttyS0,115200 root=${rootdev} rootwait rootfstype=${rootfstype} ubootdev=${boot_interface} scandelay loglevel=${verbosity} usb-storage.quirks=${usbstoragequirks} ${extraargs}"
+
+ext4load  ${boot_interface} 0:1 ${fdt_addr} ${prefix}dtb/${fdtfile}
+ext4load  ${boot_interface} 0:1 ${ramdisk_addr_r} ${prefix}uInitrd
+ext4load  ${boot_interface} 0:1 ${kernel_addr_r} ${prefix}zImage
+
+setenv fdt_high 0xffffffff
+setenv initrd_high 0xffffffff
+
+fdt addr ${fdt_addr}
+fdt resize
+
+# Update device tree node
+fdt set /soc/internal-regs/sata@e0000 status "disabled"
+fdt set /soc/internal-regs/sata@a8000 status "disabled"
+fdt set /soc/spi@10680 status "okay"
+fdt set /soc/spi@10680/spi-flash@0 status "okay"
+
+bootz ${kernel_addr_r} ${ramdisk_addr_r} ${fdt_addr}
+
+# Recompile with:
+# mkimage -C none -A arm -T script -d boot_spi_en.cmd /boot_spi_en.scr
diff --git a/docs/files/software/boot_spi_en.scr b/docs/files/software/boot_spi_en.scr
new file mode 100644
index 0000000..bcf853f
Binary files /dev/null and b/docs/files/software/boot_spi_en.scr differ
diff --git a/docs/files/software/u-boot-2013.01-spi.bin b/docs/files/software/u-boot-2013.01-spi.bin
new file mode 100644
index 0000000..4b9a8bd
Binary files /dev/null and b/docs/files/software/u-boot-2013.01-spi.bin differ
diff --git a/docs/img/hardware/dipswitch_boot_spinor.png b/docs/img/hardware/dipswitch_boot_spinor.png
new file mode 100644
index 0000000..3d610f1
Binary files /dev/null and b/docs/img/hardware/dipswitch_boot_spinor.png differ
diff --git a/docs/spi.md b/docs/spi.md
index 82f990c..8cfc082 100644
--- a/docs/spi.md
+++ b/docs/spi.md
@@ -1,2 +1,85 @@
+## Hardware
+
+System-On-Module used by Helios4 provide an SPI NOR flash [Winbond W25Q32](https://www.winbond.com/hq/product/code-storage-flash-memory/serial-nor-flash/?__locale=en&selected=32Mb#Density) connected to SPI bus 1 Chip Select 0.
+
+By default, Helios4 configured to boot from microSD card. To boot from SPI NOR flash (after [writing U-Boot into SPI NOR flash](#write-u-boot-to-spi-nor-flash)), please change Boot Mode DIP switch SW1 to:
+
+![Boot from SPI](/img/hardware/dipswitch_boot_spinor.png)
+
+
+## Build U-Boot for SPI NOR flash
+
+Refer to [U-Boot](/uboot) page to build the image.
+
 !!! info
-    Coming soon.
+    Prebuilt SPI image of U-Boot 2013.01 can be downloaded from [here](/files/software/u-boot-2013.01-spi.bin).
+
+## Write U-Boot to SPI NOR flash
+
+### Prerequisites
+
+1. Access to Helios4 Serial Console. Please refer to [Install](/install/#step-4-connect-to-helios4-serial-console) page for instructions.
+
+2. Bootable U-Boot on microSD card.
+
+### Using Linux
+
+!!! info
+    Concurrent access on SPI NOR and SATA drive can lead to unstable SATA. The following instructions has taken this issue into consideration and workaround it by disabling the SATA temporary.
+
+Put u-boot binaries on home folder and rename it as **u-boot-spi.bin**.
+Download boot_spi_en.scr from [here](/files/software/boot_spi_en.scr) and put it to / and then reboot the system
+```
+sudo wget https://wiki.kobol.io/files/software/boot_spi_en.scr -O /boot_spi_en.scr
+sudo reboot
+```
+
+Switch to Helios4 serial console. Press any key to cancel the autoboot and execute these commands
+```
+setenv script_name "boot_spi_en.scr"
+stage_boot mmc_scr
+```
+It will boot to Linux with modified device tree.
+
+- - -
+
+Log in to Helios4, verify whether mtdblock0 is exist using **lsblk**, and write the u-boot to SPI flash using this command
+
+```
+sudo dd if=~/u-boot-spi.bin of=/dev/mtdblock0
+```
+
+Set DIP switches SW1 to SPI Boot
+
+![Boot from SPI](/img/hardware/dipswitch_boot_spinor.png)
+
+and reboot the system.
+Observe the boot message on serial console, it should display
+
+```
+BootROM - 1.73
+Booting from SPI flash
+```
+
+## Set Up U-Boot
+
+Add U-Boot ENV variable.
+
+```
+setenv fdt_high 0xffffffff
+setenv initrd_high 0xffffffff
+setenv fdtfile armada-388-helios4.dtb
+saveenv
+```
+
+To automatically boot Linux on microSD card
+
+```
+setenv bootargs '${console} root=/dev/mmcblk0p1 rootwait'
+setenv bootcmd 'ext2load mmc 0:1 ${kernel_addr_r} /boot/zImage; ext2load mmc 0:1 ${ramdisk_addr_r} /boot/uInitrd; ext2load mmc 0:1 ${fdt_addr} /boot/dtb/${fdtfile}; bootz ${kernel_addr_r}  ${ramdisk_addr_r} ${fdt_addr}'
+saveenv
+```
+
+!!! info
+    The prebuilt SPI image has been configured to automatically run /boot/boot.scr and /boot.scr on microSD. There is no need to configure u-boot to boot Armbian on microSD.
+