# WM8750

# Apricot R4 on NAND, for APC.io WM8750
## Overview
{{ :gnulinux:wm8750:apc-angle.jpg?nolink&250|}}
For memory. Adapted from [[http://thunderace94.wordpress.com/2013/06/12/apc-8750-install-raspbian-on-nand-flash/|this repost]], original source: RoyalPanda from APC.IO forum.

The plot is simple: How to install a _real_ GNU/Linux on the APC.io wm8750 PicoITX board.
__Royal Panda__ made a great job adapting Raspbian for the APC, he called this remix __Apricot__

The last release is Apricot R5, but it still lacks Video support (among others things) and __Royal Panda__ didn't release any NAND installer. So this _"tutorial"_ is made with the previous release: Apricot R4. The process should stay the same if there's an update one day...

Long story short: I needed to reinstall my APC board, but the kernel I had (and though was the one from the installer) lacks the UBI support, so I couldn't follow the original Howto...

## Steps
### What you'll need

* The board itself, the original APC.io board: __[[http://apc.io/products/8750a/|WM8750]]__
* A 1 Gio MicroSD card
* An Ethernet connection
* A Serial adapter
* Screen and Keyboard might help too...

### Files

* The Installer Files with a scriptcmd file (it's easier this way, but don't worry, you'll play with uBoot via Serial)
* mtd-utils deb package (so you don't have to type the URL to download it)
* mod-kernel-RaspBian.tar.gz (the Kernel to be flashed on the NAND)

I've made a bundle with the useful files: {{gnulinux:wm8750:apricotinstaller.tar.gz|Here}}

* Apricot R4 MMC (for its rootfs): [[http://breizhcloud.eu/depot/Apricot-R4/ApricotR4-NoGUI-1G-SDCARD.img.zip|Here]]

### MicroSD preparation

The easy way is to copy the Apricot R4 img on the uSD card, then add the the other files on the first partition.
    dd if=./ApricotR4-NoGUI-1G-SDCARD.img of=/dev/sdh bs=4096
There should be one partition named __XCP-1.6.10 Base Pack__. Copy the files initrd.gz, uzImage.bin, scriptcmd, mtd-utils (DEB package) there, replace the existing files (uzImage.bin and scriptcmd)

Create a folder where you extract the mod-kernel-RaspBian.tar.gz archive. Mine's named __modKern__.

### First boot
Insert the MicroSD card, boot the board.
The debian-installer should start (on the screen, not in serial). Choose your language, you don't need the Network. Stop the installer as soon as you can, and drop to a Shell. From the menu, it's the __Execute a shell__ option.

Make sure your NAND layout is correct:
    cat /proc/mtd

You should see this:
    dev:    size   erasesize  name
    mtd0: 00d00000 00010000 "filesystem-SF"
    mtd1: 00280000 00010000 "kernel-SF"
    mtd2: 00050000 00010000 "u-boot-SF"
    mtd3: 00010000 00010000 "u-boot env. cfg. 1-SF"
    mtd4: 00010000 00010000 "u-boot env. cfg. 2-SF"
    mtd5: 00010000 00010000 "w-load-SF"
    mtd6: 00a00000 00100000 "kernel"
    mtd7: 7f600000 00100000 "rootfs"

<note warning>If your layout is different, stop here unless you know what you're doing...</note>

Mount the first partition of the uSD card somewhere, Flash the kernel on the NAND (mtd6)
    mkdir /mnt
    mount /dev/mmcblk0p1 /mnt
    cd /mnt/modKern
    dd if=uzImage.bin of=/dev/mtdblock6

<note tip>You can try to erase the mtd partition before flashing the kernel, but I'm not sure it'd work, and if that's really necessary since __dd__ does a raw copy...</note>

Shutdown the board. Unplug the uSD card.

### Second Boot
Connect your serial adapter, open with these parameters: __115200 8n1__ without any flow control.

Restart the board.__Interrupt the boot process in uBoot by pressing Enter__. It should drop you to a uBoot shell. Enter theses lines
    setenv nandargs "setenv bootargs mem=460M ubi.mtd=7 root=/dev/mmcblk0p2 console=ttyS0,115200n8 console=tty0 mtdparts=WMT.nand:10m(kernel),-(rootfs)"
    setenv nandboot "nandrw r 0x0 0x1000000 0x400000;  if iminfo 0x1000000; then run nandargs; bootm 0x1000000; fi"
then
    boot
When the Kernel starts booting, insert the uSD card so it can find the rootfs. When the system is ready, you should be able to connect using SSH. Login: __root__, password: __apricot__. Use the physical screen and keyboard to find out the IP address 

From now it's pretty much the same as the original HowTo. Format the mtd7 partition (the __rootfs__)
    mount /dev/mmcblk0p1 /mnt
    dpkg -i /mnt/mtd-utils_1.5.0-1_armhf.deb
    umount /mnt
    ubidetach -d 0
    ubiformat /dev/mtd7
    ubiattach -p /dev/mtd7
    ubimkvol /dev/ubi0 -m -N rootfs
    mount -t ubifs ubi0:rootfs /mnt

Debootstrap Time ! It ccan be quite long, so... once you've seen it's start correctly, go do something else, have a coffe, take a (short) nap, ...
    apt-get install -y debootstrap
    debootstrap --no-check-gpg wheezy /chroot http://mirrordirector.raspbian.org/raspbian/

Once it's done, you can chroot in your new system !
    mount -t proc none /mnt/proc
    mount -t sysfs none /mnt/sys
    mount -o bind /dev /mnt/dev
    chroot /mnt

You should now be using the rootfs on NAND, time to setup the Raspbian distro
    mount /dev/mmcblk0p1 /mnt
    cp -R /mnt/modKern/modules /lib/
    depmod

Install uBoot tools to be able to change the uBoot parameters if/when you need
    apt-get install u-boot-tools
    echo "/dev/mtd3 0x0000 0x10000 0x10000" > /etc/fw_env.config
    echo "/dev/mtd4 0x0000 0x10000 0x10000" >> /etc/fw_env.config
    fw_printenv ## Should print the uBoot env

Make the previous setenv changes permanent:
    fw_setenv nandargs "setenv bootargs mem=460M ubi.mtd=7 root=ubi0:rootfs rootfstype=ubifs console=ttyS0,115200n8 console=tty0 mtdparts=WMT.nand:10m(kernel),-(rootfs)"
    fw_setenv nandboot "nandrw r 0x0 0x1000000 0x400000;  if iminfo 0x1000000; then run nandargs; bootm 0x1000000; fi"

Setup you debian installation
    passwd 
    echo "proc /proc proc defaults 0 0" >> /etc/fstab
    echo "ubi0:rootfs / ubifs defaults 0 0" >> /etc/fstab
    echo "" >> /etc/network/interfaces
    echo "allow-hotplug eth0" >> /etc/network/interfaces
    echo "iface eth0 inet dhcp" >> /etc/network/interfaces

Install the SSH server
    apt-get update
    apt-get install openssh-server tmux

Edit the inittab to enable a serial session, just in case...
    nano /etc/inittab

That should be it, you can safely poweroff the board, unplug the uSD card, then reboot.

### That's all folks !

Well, you now have a working Debian Wheezy system. I haven't tested all the graphic part, since it's running as server under my desk, but it should work fine...

## Troubleshooting

__The board doesn't start ?__ Even with Firmware 1.2, it seems the board sometimes needs a screen attached to complete the boot process and connect to the network...