D-Link DNS-320 & DNS-325 NAS: Replacing Firmware

↑Running u-boot via Serial

This isn't strictly necessary, but it's definitely worth checking you can boot via. serial first, so you know you can unbrick the NAS. There is mainline DNS-325 support, but DNS-320 isn't accepted just yet. As a result you need to use my branch.

1. Compile u-boot.kwb

   host:~$ git clone -b dns320_support https://github.com/lentinj/u-boot.git
   host:~$ cd u-boot
   host:u-boot$ export CROSS_COMPILE=arm-linux-gnueabi-
   # Obviously, use dns325_config for a DNS-325
   host:u-boot$ make distclean && make dns320_config && make u-boot.kwb

2. Turn NAS off
3. Close any open terminal window to the NAS
4. Get your PC ready to boot

   # Replace /dev/ttyUSB1 with your serial port
   host:u-boot$ ./tools/kwboot -p -b u-boot.kwb -B115200 -t /dev/ttyUSB1

5. Turn NAS on. Be patient, it can take some time to recognise the boot message and sometimes halt with xmodem: Bad message. Lowering baud rate does not help.
6. Be ready to interrupt u-boot from booting.

The DNS-325 is a lot better at doing this than the DNS-320. You may have more luck with kwuartboot. kwuartboot cannot patch an image to boot from UART (the -p option). Instead you have to recompile with "BOOT_FROM uart" set in board/d-link/dnskw/kwbimage.dns320.cfg

At this point, you should have a u-boot prompt but the default environment. You might want to play around a bit to see what you can do, there are notes at the bottom of the page.

↑Writing a new u-boot image

NB: Newer stock versions of u-boot cannot boot the original D-link kernels. I'm not sure why this is but if this is likely to be an issue for you then don't do this, or at very least keep a backup.

You can either compile the image with the following...

1. Ensure you have "BOOT_FROM nand" set in board/d-link/dnskw/kwbimage.dns320.cfg
2. Compile u-boot.kwb

   host:u-boot$ export CROSS_COMPILE=arm-linux-gnueabi-
   # Obviously, use dns325_config for a DNS-325
   host:u-boot$ make distclean && make dns320_config && make u-boot.kwb

...or download it. Here are 2 kwb images for the DNS-320 and DNS-325 (unlike the kernel, there isn't a dramatic advantage in having the latest and greatest, so thought I'd upload these here).

1. Copy the u-boot.kwb onto a ext2 USB stick, or somwhere TFTP-able.
2. Using u-boot, load it into memory and write it to the NAND.

   Marvell>> usb reset ; ext2load usb 0:1 0x1000000 /u-boot.kwb
   Marvell>> nand erase 0x000000 0xe0000
   Marvell>> nand write 0x1000000 0x000000 0xe0000
   Marvell>> reset

3. Cross fingers! Note that the new u-boot will still countdown so be ready to interrupt the process.
4. At this point your u-boot environment should be very minimal. You will want to set at least the following.

   => setenv ethaddr 00:50:43:xx:xx:xx [Any MAC address]
   => setenv ipaddr [Our IP address, e.g. 10.150.1.3]
   => setenv serverip [Where TFTP server is, e.g. 10.150.1.10]
   => setenv cmdlinepart.mtdparts 'mtdparts=orion_nand:896k(u-boot),128k(u-boot-env),-(root)'
   Marvell>> saveenv
   Saving Environment to NAND...
   Erasing Nand...Writing to Nand... done

NB: Previously this page suggested setenv mtdparts, which longer works as of Debian Buster. Old installations will need the environment updated.

↑Building a root filesystem image

Follow the the instructions on the keeping original frimware.

I have no name!@host:/# cat <<EOF > etc/fstab
/dev/root   /       ubifs   sync,noatime    0 0
EOF

If you have replaced u-boot, then you no longer have to append the devicetree file to the kernel image:

I have no name!@host:/# cat <<'EOF' > etc/kernel/postinst.d/zz-local-build-image
#!/bin/sh -e
# passing the kernel version is required
version="$1"
[ -z "${version}" ] && exit 0

cp /usr/lib/linux-image-${version}/kirkwood-dns*.dtb /boot/

/usr/bin/mkimage -A arm -O linux -T kernel -C none -n uImage \
                 -a 0x00008000 -e 0x00008000 \
                 -d /boot/vmlinuz-${version} /boot/uImage-${version}
ln -sf /boot/uImage-${version} /boot/uImage

/usr/bin/mkimage -A arm -O linux -T ramdisk -C gzip -n uInitrd \
                 -a 0x00e00000 -e 0x00e00000 \
                 -d /boot/initrd.img-${version} /boot/uInitrd-${version}
ln -sf /boot/uInitrd-${version} /boot/uInitrd
EOF
I have no name!@host:/# chmod a+x /etc/kernel/postinst.d/zz-local-build-image
# Recreate the kernel package to create the images to boot from
I have no name!@host:/# dpkg-reconfigure $(dpkg --get-selections | grep linux-image-3 | cut -f1)

host:# mkdir cruft ; mv \
        rootfs/usr/share/man \
        rootfs/usr/share/doc \
        rootfs/lib/modules \
        cruft/
host:# cat <<EOF > rootfs/etc/dpkg/dpkg.cfg.d/excludes
path-exclude=/usr/share/man/*
path-exclude=/usr/share/doc/*
EOF

host:~$ /usr/sbin/mkfs.ubifs -v -r rootfs -m 2048 -e 129024 -c 1016 -x zlib -o ubifs.img

↑Formatting NAND with UBIFS

Like HDDs, NAND chips can be divided into partitions. However, the table itself isn't stored on the device, it's a configuration option. By default D-Link by default divide it into 6, which is what the mainline kernel does also.

We only want 2 partitions, one for u-boot, the other for the UBIFS filesystem. We set this in mtdparts, and tell both u-boot and the Linux kernel:

=> setenv mtdparts 'mtdparts=orion_nand:896k(u-boot),128k(u-boot-env),-(root)'
=> setenv bootargs 'console=ttyS0,115200 ${mtdparts}'
=> saveenv
Saving Environment to NAND...
Erasing Nand...Writing to Nand... done

We can now format the rest of the NAND with UBI, make a volume within this, and write our UBIFS image into it:

# NB: If you already have UBI installed on your NAND, this isn't the way
# to reinstall it, as the erase counters will not be preserved.
=> nand erase.part root
=> ubi part root
 . . .
UBI: empty MTD device detected
UBI: create volume table (copy #1)
UBI: create volume table (copy #2)
 . . .
=> ubi create rootfs
No size specified -> Using max size (129153024)
Creating dynamic volume rootfs of size 129153024
=> usb reset ; ext2load usb 0:1 0x1000000 /ubifs.img
 . . .
Loading file "/ubifs.img" from usb device 0:1
60512256 bytes read
=> ubi write 0x1000000 rootfs 0x[60512256 in hex]
60512256 bytes written to volume rootfs
=> ubifsmount rootfs # or ubifsmount ubi:rootfs with newer u-boot versions
UBIFS: mounted UBI device 0, volume 0, name "rootfs"

Alternatively, if the NAS is already booted, you can use ubinize and ubiformat to re-flash the filesystem image.

Finally, reboot and modify U-Boot environment so that loads the kernel from our new FS:

=> setenv root_flash 'ubi.mtd=root root=ubi0:rootfs rootfstype=ubifs'
=> setenv load_net 'tftp 0x0900000 kirkwood-dns320.dtb ; tftp 0x1000000 dlink-nas.img'
=> setenv load_ubifs 'ubi part root ; ubifsmount rootfs ; ubifsload 0x0900000 /boot/kirkwood-dns320.dtb ; ubifsload 0x1000000 /boot/uImage ; ubifsload 0x1260000 /boot/uInitrd'
# Or, with newer u-boot revisions... "ubifsmount ubi:rootfs"
=> setenv console 'ttyS0,115200'
=> setenv optargs ''
=> setenv bootcmd 'setenv bootargs console=${console} ${optargs} ${mtdparts} ${root_flash} ; run load_ubifs ; bootm 0x1000000 0x1260000 0x0900000'
=> saveenv
Saving Environment to NAND...
Erasing Nand...Writing to Nand... done

Now you should be booting Linux, with no remains of D-Link (well, beyond the massive letters on the side).

↑Saving space

You've probably noticed that the flash chip is 128MB, and the above squeezes a full-fat Linux distribution onto it. This works, but be wary of what you install. The following also help

• Move /var/lib/apt, /var/lib/dpkg, /var/cache/apt, /var/cache/debconf onto a partition on the HDD. They are only needed when running apt-get, and can get pretty big.
• Stop syslogd, log over the network to a different host, or use busybox-syslogd's ring buffer.
• You may want some swap space on the HDDs for when running memory intensive processes, e.g. fsck.

*.emerg                         *
*.*                             @[log server IP / hostname]

↑Next Steps

• Userland configuration

↑Appendix: Using a mainline u-boot

A few tips on how to do things in u-boot.

=> usb start
(Re)start USB...
USB:   Register 10011 NbrPorts 1
USB EHCI 1.00
scanning bus for devices... 2 USB Device(s) found
       scanning bus for storage devices... 1 Storage Device(s) found
=> usb storage
  Device 0: Vendor: pqi      Rev: 1100 Prod: IntelligentStick
            Type: Removable Hard Disk
            Capacity: 7725.0 MB = 7.5 GB (15820800 x 512)

=> ext2ls usb 0:1
<DIR>       4096 .
<DIR>       4096 ..
<DIR>      16384 lost+found
         3029296 dlink-nas.img
=> ext2load usb 0:1 0x1000000 dlink-nas.img

=> ubi part root
Creating 1 MTD partitions on "nand0":
0x000000300000-0x000008000000 : "mtd=3"
. . .
=> ubifsmount rootfs
UBIFS: mounted UBI device 0, volume 0, name "rootfs"
=> ubifsls
<DIR>        5648  Sat Mar 24 14:43:26 2012  bin

=> set ncip ${serverip} ; set stdin nc; set stdout nc; set stderr nc

host:u-boot$ ./tools/netconsole 10.150.1.2

↑Appendix: Compiling a kernel

You don't need to compile a kernel any more, but just in case you want to anyway here are some notes. Any Linux 3.6+ kernel will have support for the NASes built in. You will need an ARM cross compiling toolchain, see instructions here:

host:~$ cd ${kernel_source}
# Set up cross-compiler
host:linux-2.6$ alias cross-make='make ARCH=arm CROSS_COMPILE=arm-linux-gnueabi- LOADADDR=0x00008000'
# Configure kernel
host:linux-2.6$ cat arch/arm/configs/mvebu_v5_defconfig - <<EOF > .config
### Extra options atop kirkwood_defconfig
CONFIG_MACH_DLINK_KIRKWOOD_DT=y
CONFIG_SERIAL_OF_PLATFORM=y
CONFIG_HWMON=y
CONFIG_SENSORS_GPIO_FAN=y
CONFIG_MTD_UBI=y
CONFIG_UBIFS_FS=y
EOF
host:linux-2.6$ cross-make menuconfig # If you need to
# Compile
host:linux-2.6$ cross-make -j5 uImage modules kirkwood-dns320.dtb kirkwood-dns325.dtb

Copy a kernel into the filesystem for the NAS:

host:linux-2.6$ cp arch/arm/boot/uImage rootfs/boot/uImage-${version}
host:linux-2.6$ cp arch/arm/boot/kirkwood-dns320.dtb rootfs/boot/kirkwood-dns320-${version}.dtb
host:linux-2.6$ cp arch/arm/boot/kirkwood-dns325.dtb rootfs/boot/kirkwood-dns325-${version}.dtb
host:linux-2.6$ cross-make -j5 modules
host:linux-2.6$ cross-make INSTALL_MOD_PATH=rootfs modules_install

And use symlinks to specify which kernel we want to boot by default:

host:linux-2.6$ cd rootfs/boot
host:boot$ ln -s uImage-${version} uImage
host:boot$ ln -s kirkwood-dns320-${version}.dtb kirkwood-dns320.dtb
host:boot$ ln -s kirkwood-dns325-${version}.dtb kirkwood-dns325.dtb