NAND Customization

Astra supports using NAND for the main internal storage with SL2610. The machine types sl2611nand, sl2615nand, and sl2619nand are configured to use a default 256MB SPI NAND (2K page size). However, other NAND configurations can be used. This guide details how to modify the SDK to use different NAND configurations.

Changing the NAND Configuration

The NAND configuration is included in the synasdk-config-native` package. Use the devtool utility to modify the config file:

devtool modify synasdk-config-native

The devtool utility will create the build-sl2619nand/workspace/sources/synasdk-config-native/configs/product directory which will contain the source for the config package. In the product directory is a subdirectory containing a config file for each of the platforms. Modify the files based on the sections below.

Changing the NAND Size

The NAND configuration is defined in the Image Generation Configuration of the profile defconfig file.

Image Generation Configuration section of the defconfig

Update the sizes for your specific NAND. For example, switching to a 512MB (4K) NAND wou

Patch updating sizes in sl2619_nand_poky_aarch64_rdk_defconfig.

Changing Partition Sizes

The NAND partition layout is set in the nand.pt file.

Updating the NAND Flash Type Configuration

Changing the Flash Type Configuration

The Flash Type configuration is stored in flash_type.cfg file.

Updating the NAND Flash Type Configuration

Changing the NAND Width

Updating the NAND Width in U-Boot

The NAND width is configured in the Linux and U-Boot devicetree . The default width is 2 for a Dual SPI Configuration. Update the dts file widths to 4 for Quad SPI Configuration.

The NAND U-Boot devicetree is included in the syna-u-boot package. Use the devtool utility to modify the config file:

devtool modify syna-u-boot

The devtool utility will create the build-sl2619nand/workspace/sources/syna-u-boot/boot/u-boot directory which will contain the source for

Modify the spi-tx-bus-width and spi-rx-bus-width in arch/arm/dts/klamath-rdk-nand.dts.

Updating the NAND Width in Device Tree

Updating the NAND Width in Linux

The NAND Linux devicetree is included in the linux-syna package. Use the devtool utility to modify the config file:

devtool modify linux-syna

The devtool utility will create the build-sl2619nand/workspace/sources/linux-syna directory which will contain the source for

Modify the spi-tx-bus-width and spi-rx-bus-width in arch/arm64/boot/dts/synaptics/sl2619-nand-rescue-rdk.dts.

Updating the NAND Width in Device Tree

Building the Updated Image

Finally, build an image with the modified NAND configuration:

bitbake -f synasdk-config-native
bitbake -f syna-u-boot -c compile
bitbake -f linux-syna -c compile
bitbake -f astra-media -c compile
bitbake -f astra-media

The custom NAND image will be output to /path/to/workspace/sdk/build-sl2619nand/tmp/sl2619nand/deploy/images/sl2619nand/SYNAIMG/uNAND_full.img or something similar based on the name of the machine type.

USB Boot with NAND support

You will also need to build a USB boot image with support for your NAND device in order to flash your custom NAND image over USB.

Building a custom USB boot image with NAND support

Please follow the instructions in Building Custom USB Boot Images and apply the appropriate NAND configuration.

The custom USB NAND image will be output to /path/to/workspace/sdk/build-sl2619usb/tmp/sl2619usb/deploy/images/sl2619usb/SYNAIMG or something similar based on the name of the machine type.

Flashing the NAND image

Flashing the NAND image over USB uses the astra-boot tool which is part of the usb-tool / astra-update package. Information on downloading the tool can be found in the user guide at Updating Software Images using USB.

Flashing the NAND image also requires a serial console to input commands at the U-Boot prompt. The user guide also has instructions for setting up the serial console at Setting up the Serial Console.

Unlike flashing eMMC or SPI images, flashing the NAND image requires booting over USB using the astra-boot tool.

First copy the USB boot image generated in the previous section to the usb-tool directory.

Second copy the uNAND_full.img to the USB boot SYNAIMG directory. astra-boot will load the image from this directory.

Finally, boot the device using astra-boot.

./bin/linux/astra-boot -k SYNAIMG

.\bin\win\astra-boot.exe -k SYNAIMG

The device will boot to the U-Boot prompt (=>). At the U-Boot prompt enter the following commands.

usbload uNAND_full.img 0x10000000
m2nand 0x10000000

This will load the uNAND_full.img image to address 0x10000000 and then program it to the NAND. U-Boot will return to the prompt when the operation is complete. Then you may reboot the device.