====== How to install ArchLinux on AC100 with GPT ======

You need:

  * A computer with ArchLinux (64bit)
  * A mini-usb cable
  * A Toshiba AC100
  * An USB stick (at least 256MB)
  * About 4-5 hours of time

===== Download a kernel =====

You can download a prebuilt one here: [[http://kilbeggan.fourecks.de/~falk/linux-3.15.6_archlinux_ac100.tar.gz]]

===== Build a kernel =====

Create a working directory: ''mkdir ~/ac100''

Get precompiled Crosstools from [[http://archlinuxarm.org/developers/distcc-cross-compiling]], use the ARMv7i hardfloat version. 

Unpack the tools in to ''~/ac100'', this will result in ''~/ac100/x-tools7h''

Add the binaries to your path: ''export PATH=$PATH:~/ac100/x-tools7h/arm-unknown-linux-gnueabi/bin'' 

Checkout a working kernel sourcetree. I recommend current vanilla kernel (3.15.6), it should work out of the box. 

Create a directory for (kernel) installation: ''mkdir ~/ac100/kernel_install'' 

 
==== Building the kernel ====

  $ cd ~/ac100/linux-3.15.6
  $ make tegra_defconfig ARCH=arm
  $ make menuconfig ARCH=arm
  
Be sure to have a look under "Boot Options" and enable:

  * Use appended device tree blot to zImage 
  * Supplement the appended DTB with traditional ATAG information
  * Kernel command line type (Use bootloader kernel arguments if available)

Or use [[http://sprunge.us/RiBc]] as a base .config and do a 

  $ cd ~/ac100/linux-3.15.6
  $ curl http://sprunge.us/RiBc > .config 
  $ make oldconfig ARCH=arm

Build your kernel: 

  $ make -j8  zImage modules INSTALL_MOD_PATH=/home/user/ac100/kernel_install \
    INSTALL_MOD_STRIP=1 ARCH=arm CROSS_COMPILE=arm-unknown-linux-gnueabi-
  ... lots of output ... 
  $ make modules_install INSTALL_MOD_PATH=/home/user/ac100/kernel_install \
    INSTALL_MOD_STRIP=1 ARCH=arm CROSS_COMPILE=arm-unknown-linux-gnueabi-
  ...
  $ make dtbs INSTALL_MOD_PATH=/home/user/ac100/kernel_install \
    INSTALL_MOD_STRIP=1 ARCH=arm CROSS_COMPILE=arm-unknown-linux-gnueabi-
  ... 
  $ mkdir -p ~/ac100/kernel_install/boot/
  $ cat ~/ac100/marvin24s-kernel/arch/arm/boot/zImage \
        ~/ac100/marvin24s-kernel/arch/arm/boot/dts/tegra20-paz00.dtb >
        ~/ac100/kernel_install/boot/vmlinuz-for-next-thierry
  $ cd ~/ac100/kernel_install/
  $ mkdir usr ; mv lib usr # breaks arch otherwise
  $ tar cf kern.tar boot usr 

Congratulations, you should have a working kernel. 
===== Installing on your AC100 =====

Copy ''kern.tar'' and [[http://archlinuxarm.org/os/ArchLinuxARM-trimslice-latest.tar.gz|ArchLinuxARM-trimslice-latest.tar.gz]] on a USB Stick

Get [[nvflash]] and [[https://dl.dropboxusercontent.com/u/40761340/sos-uboot-r5-alpha.bin|SOS-Boot-r5]]

[[backupandrestore|Backup]] your AC100.

Boot your AC100 in recovery mode (Ctrl+Esc+Power), attach the mini-USB cable to your Host PC. 

Send sos-uboot-r5-alpha.bin to your AC100:

  nvflash --bl sos-uboot-r5-alpha.bin --sync 
  
Insert your prepared USB stick into your AC100. On your AC100 do the following: 

  # ./switch-to-uboot
  (you did backup your device, did you?)
  
  # parted /dev/mmcblk0
  
  (delete everything, create one big partition starting at 1576k, ending at 8000M)
  
  # mkfs.ext4 /dev/mmcblk0p1
  # mount /dev/sda1 /mnt 
  # mount /dev/mmcblk0p1 /media 
  # cd /media 
  # gzip -dc /mnt/ArchLinuxARM-trimslice-latest.tar.gz | tar xp 
  # tar xf /mnt/kern.tar 
  # cd /media/boot
  # vi boot.cmd
  
Fill boot.cmd with the following: 

  echo === AC100 Arch Linux ===
  setenv bootargs 'root=/dev/mmcblk0p1 init=/usr/lib/systemd/systemd rw quiet cma=64M'
  ext2load mmc 0:1 0x1000000 /boot/vmlinuz-for-next-thierry
  bootz 0x1000000
  
Create a boot script for uboot:

  # mkimage -A arm -O linux -T script -C none -a 0 -e 0 -n "ubootscript" -d boot.cmd boot.scr

Unmount disks

  # cd / ; umount /mnt ; umount /media

Remove your USB stick and reboot your AC100 with long press on the powerbutton. 

You should have a (very) basic ArchLinuxArm system now. Log in with "root"/"root" and hack away. 

For increased X11 performance build the opentegra driver according to [[http://ac100.wikispaces.com/opentegra]], you need to install libpthread-stubs from AUR [[https://aur.archlinux.org/packages/libpthread-stubs]] and ''xorg-server-devel'' from pacman. 

First, build the modified libdrm:

  git clone git://people.freedesktop.org/~tagr/drm
  cd drm
  ./autogen.sh --prefix=/usr --disable-intel --disable-nouveau --disable-radeon --disable-vmwgfx --enable-tegra-experimental-api
  make
  make install
  
Then, build the opentegra driver: 

  git clone git://people.freedesktop.org/~tagr/xf86-video-opentegra
  cd xf86-video-opentegra
  ./autogen.sh --prefix=/usr
  make
  make install