This page explains how to build up environment to develop QEMU SH4 System Emulation. These works are done 2009 April, on Ubuntu 8.10 ja.

QEMU

Get qemu-sh source code and build it.

First, get qemu git tree.

    % git clone git://git.savannah.nongnu.org/qemu.git qemu
    % ls qemu

Second, get qemu-sh patches. % git clone git://github.com/kawasaki/qemu-sh.git % ls qemu-sh

Following operations are explained in qemu-sh/README.

    % cd qemu
    % QUILT_PATCHES=../qemu-sh quilt push -a

Build qemu.

    % ./configure --target-list=sh4-softmmu
    % make
    % ./sh4-softmmu/qemu-system-sh4

I recommend to specify --target-list option to reduce build time.

Linux Kernel and Userland

For quick start, you can get built kernel and userland.

Build Linux Kernel for SH according to LinuxSH Wiki.

First of all, obtain the tool chain for SH4.

    % mkdir /opt/gnush4
    % cd /opt/gnush4
    % wget http://userweb.kernel.org/~lethal/toolchains/gnush4_linux_v0702_rc-1-1.i386.tar.gz
    % tar zxvf gnush4_linux_v0702_rc-1-1.i386.tar.gz

Then obtain kernel source. I followed git-howto. Git-clone takes a long time.

    % git-clone git://git.kernel.org/pub/scm/linux/kernel/git/lethal/sh-2.6.git sh-2.6
    % cd sh-2.6
    % git pull git://git.kernel.org/pub/scm/linux/kernel/git/lethal/sh-2.6.git

Configure kernel. R2D+ is the appropriate target hardware emulated by QEMU.

    % make ARCH=sh rts7751r2dplus_defconfig
    % make ARCH=sh CROSS_COMPILE=/opt/gnush4/usr/share/gnush4_linux_v0702_rc-1/bin/sh4-linux- menuconfig

Inhibit iotrap which is necessary for R2D+ real hadware, because it causes bit performance down.

Boot options
  Default bootloader kernel arguments
    [edit it to add 'noiotrap' option at the end of command line.]

To utilize network interface, we need to change network driver settings. Enable the following option.

Device Drivers
  Network Device Support
     Ethernet (10 or 100 Mbit)
         <*> RealTek RTL-8139 C+ PCI Fast Ethernet Adapter support.

Build it.

    % make ARCH=sh CROSS_COMPILE=/opt/gnush4/usr/share/gnush4_linux_v0702_rc-1/bin/sh4-linux- zImage

Userland disk image is available from here.

Get and unpack it.

   % tar jxvf sh-test-0.1.tar.bz2

How to invoke QEMU

The command I use is like this.

     % ./qemu/sh4-softmmu/qemu-system-sh4 -M r2d -serial vc -serial stdio -m 1024M -kernel ./sh-2.6/arch/sh/boot/zImage -usb -usbdevice keyboard -hda sh-linux-mini.img

The vc serial console shows QEMU monitor, which is easy to quit QEMU cleanly with 'q' command. The '-m' option seems necessary to avoid memory shortage for initramfs. The '-usb' and '-usbdevice keyboard' options provides key input feature.

Then the kernel starts booting and graphics console will appear. Have fun!

The system is not so stable. Sometimes segmentation fault occurs.

If you notices any mistakes, please tell it via mail to kawasaki (at mark) juno (dot) dti (dot) ne (dot) jp.