Supported Devices

Versatile express

Introduction

Qemu emulation platform for Versatile-express

CPU Information Processor : ARMv7 Processor rev 0 (v7l) processor : 0 BogoMIPS : 756.94 Features : swp half thumb fastmult vfp edsp neon vfpv3 tls CPU implementer : 0x41 CPU architecture: 7 CPU variant : 0x0 CPU part : 0xc09 CPU revision : 0 Hardware : ARM-Versatile Express Revision : 0000 Serial : 0000000000000000 boot.log

Installation

Enviroment preparation

• Get the needed files:
  • zImage-4.9.6
  • modules-4.9.6.tar.xz
  • vexpress-v2p-ca9.dtb
  • crux-arm-rootfs-3.3.tar.xz
• Create a hd image

$ qemu-img create hd.img 1G
$ mkfs.ext2 -F -m 0 -b 1024 hd.img

• Install the rootfs in the new hd

$ sudo mount -o loop -t ext2 hd.img /mnt
$ sudo rm -rf /mnt/lost+found
$ sudo tar -C /mnt -pxvf crux-arm-rootfs-3.3.tar.xz
$ sudo tar -C /mnt -pxvf modules-4.9.6.tar.xz

Setting up the enviroment

• Check before umounting the hd you have made the needed changes (rc.conf, fstab, net, serial...). We shall see later how to

configure certain files.

Booting the system

• Booting up

$ qemu-system-arm -M vexpress-a9 -cpu cortex-a9 -m 1024 -kernel zImage-4.9.6 -sd hd.img 
-dtb vexpress-v2p-ca9.dtb -append "rw console=ttyAMA0 console=tty root=/dev/mmcblk0"

Configuration

Serial console

• To obtain serial access we need to make some modifications to two files:
• Adding in /etc/inittab:

T0:23:respawn:/sbin/agetty -L ttyAMA0 9600 vt100

• and in /etc/securetty:

ttyAMA0

Add a swap file

# dd if=/dev/zero of=/var/swap bs=128K count=1024
1024+0 records in
1024+0 records out
134217728 bytes (134 MB) copied, 22.2331 s, 6.0 MB/s
# mkswap /var/swap
Setting up swapspace version 1, size = 131068 KiB
no label, UUID=882f6a5c-12a8-4cbd-9e45-d0cdaac2c2f7
# swapon /var/swap

Booting from Initrd

• Download initrd.gz
• Running qemu with graphics:

$ qemu-system-arm -M vexpress-a9 -cpu cortex-a9 -kernel zImage-4.9.6 -initrd initrd.gz
-dtb vexpress-v2p-ca9.dtb -append "root=/dev/ramdisk console=tty"

• Running qemu by serial

$ qemu-system-arm -M vexpress-a9 -cpu cortex-a9 -nographic -kernel zImage-4.9.6 -initrd initrd.gz
-dtb vexpress-v2p-ca9.dtb -append "root=/dev/ramdisk console=ttyAMA0"