Xen ARM with Virtualization Extensions/Arndale
The Arndale board is now supported in Xen upstream.
Preparing the board
The bootloader provided with the Arndale does not let Xen boot in hypervisor mode, so we will use the u-boot provided by Linaro.
Follow the step on the Linaro wiki, to build and install u-boot.
Building Xen and Linux Dom0
First, we will build Linux for dom0 to have a device tree to provide to Xen.
You can get a tree from xenbits which is built on top of the linaro tree 13.07, ie linux 3.10.1, (last tag is arndale-130927).
Use this config file and add anything you need.
git clone -b arndale git://xenbits.xen.org/people/julieng/linux-arm.git linux cd linux make arndale_ubuntu_defconfig make zImage make dtbs
The device tree used by the Arndale board is located in arch/arm/boot/dts/exynos5250-arndale.dtb
Then, Build Xen on ARM.
For the moment, xen doesn't build uImage for U-Boot. You can create the image with:
mkimage -A arm -T kernel -a 0x80200000 -e 0x80200000 -C none -d "$xen_src/xen/xen" xen-uImage
where $xen_src is the root directory of your xen git. Note that before commit 47d1a51 (xen: arm: make zImage the default target which we install) it was necessary to use $xen_src/xen/xen.bin instead.
Building linux DomU
To build linux for Domu, get the source tree from the repo, which contains arndale-domU-3.9 branch (last tag is arndale-domU-3.9-130405).
git clone -b arndale-domU-3.9 http://xenbits.xen.org/gitweb/?p=people/julieng/linux-arm.git linux-domU cd linux-domU make xen_domU_arndale_defconfig make zImage make dtbs
Booting Xen and Dom0
To boot Xen and Dom0, you can use:
- PXE: it's easier for development but you need a computer which act as a server;
- copy binary on the SD card: when you don't have network on your board.
Once you have chosen the boot method, you can start to follow steps in the next sections. When you have finished to configure your board, you can:
- Save the U-Boot configuration with saveenv command. The next time you want to reboot your board, you won't have to reconfigure U-Boot.
- Boot with boot command.
Booting via PXE
The following script allow U-boot to download everything via tftp and boot xen.
- Setup the PXE Server
- Copy xen-uImage, the zImage (rename in linux-zImage), exynos5250-arndale.dtb in /tftpboot/
- Copy the script in /tftpboot
wget http://xenbits.xen.org/people/julieng/load-xen-tftp.scr.txt mkimage -T script -C none -d load-xen-tftp.scr.txt /tftpboot/load-xen-tftp.img
- At U-Boot prompt, on your board, you need to set the following variable:
setenv ipaddr 10.y.y.y setenv serverip 10.x.x.x setenv tftp_path '10.x.x.x:' setenv usbethaddr 00:zz:zz:zz:zz:zz setenv ethaddr 00:zz:zz:zz:zz:zz setenv xen_addr_r 0x50000000 setenv kernel_addr_r 0x60000000 setenv dtb_addr_r 0x42000000 setenv script_addr_r 0x40080000 setenv xen_path /xen-uImage setenv kernel_path /linux-zImage setenv dtb_path /exynos5250-arndale.dtb setenv bootcmd 'tftpboot $script_addr_r /load-xen-tftp.img; source $script_addr_r'
with:
- 10.y.y.y the ip addr of the board
- 10.x.x.x the ip of a tftp server (or PXE server).
- 00:zz:zz:zz:zz:zz the MAC address of the board. You can generate it with the following
- shell command:
bash -c 'printf "00:16:3e:%02x:%02x:%02x\n" $(( $RANDOM % 256 )) $(( $RANDOM % 256 )) $(( $RANDOM % 256 ))'
Booting directly on the SD card
- Copy xen-uImage and the zImage the root directory of you SD card.
- At U-Boot prompt, on your board, you need to set the following variable:
setenv kernel_addr_r 0x60000000 setenv xen_addr_r 0x50000000 setenv bootcmd_load_linux_mmc 'ext2load mmc 1:0 $kernel_addr_r /zImage' setenv boot_xen_mmc 'run bootcmd_load_linux_mmc; ext2load mmc 1:0 $xen_addr_r /xen-uImage; bootm $xen_addr_r -' setenv bootcmd 'run boot_xen_mmc'
We assume the SD card has only 1 partition with ext2 filesystem.
- execute the boot command with the following command:
boot
Resources
- Information about the Arndale board development: www.arndaleboard.org/wiki/index.php/WiKi.
- Linaro page about the Arndale board: wiki.linaro.org/Boards/Arndale/Setup/PXEBoot