Simulate-IOT.md

+This wiki shows how to simulate D-link 850L with Qemu:
+
+**Install qemu**
+
+Download qemu with wget：
+
+`wget https://download.qemu.org/qemu-5.2.0.tar.xz`
+
+`tar xvJf qemu-5.2.0.tar.xz`
+
+`cd qemu-5.2.0`
+
+Install some dependent tools:
+
+`sudo apt-get install build-essential libcairo2-dev libpango1.0-dev libjpeg-dev libgif-dev librsvg2-dev`
+
+Install ninja：
+
+`apt install re2c
+
+`git clone git://github.com/ninja-build/ninja.git && cd ninja`
+
+`sudo ./configure.py --bootstrap`
+
+`cp ninja /usr/bin/`
+
+![image](uploads/a4485d02acdd4aab52cca2e84d4a4df3/image.png)
+
+Install qemu；
+
+`./configure`
+
+`Make`
+
+`Make install`
+
+**Use System emulation to simulate the Router D_Link 850L**
+
+For QEMU in system mode, we need to provide the emulator with a file system image and a kernel to use in the boot process. 
+Using a pre-compiled Debian MIPS kernel with a MIPS QCOW2 file system image, boot the VM, copy the DIR-850L’s extracted squashfs root into the VM, and then create a new chroot.
+
+
+1.Getting squashfs root
+Download the firmware from the internet and extracting the device firewre with binwalk.
+`sudo apt-get -y install unzip`
+`unzip DIR-850L_REVA_FIRMWARE_1.00.B07.ZIP`
+`binwalk -e DIR850LA1_FW114WWb07.bin`
+
+2.Getting a kernal and file system image
+'mkdir linux_mips; cd linux_mips'
+'wget https://people.debian.org/~aurel32/qemu/mips/vmlinux-3.2.0-4-4kc-malta'
+`wget https://people.debian.org/~aurel32/qemu/mips/debian_wheezy_mips_standard.qcow2`
+
+3.Booting the vm
+`qemu-system-mips -M malta -kernel vmlinux-3.2.0-4-4kc-malta -hda debian_wheezy_mips_standard.qcow2 -append "root=/dev/sda1" -nographic -net nic -net user,id=tcp,hostfwd=tcp::5022-:22,hostfwd=tcp:5023:23,hostfwd=tcp:48101:48101`
+
+
+
+4.Copying the squashfs root
+ensure that the sshd is running inside the MIPS VM:
+`root@debian-mips:~# service ssh start; service ssh status
+Starting OpenBSD Secure Shell server: sshd.
+sshd is running.
+root@debian-mips:~#`
+
+back on the host OS, tar up the contents of the squashfs root and copy it into the guest VM:
+
+$ tar zcf squashfs-root.tar.gz squashfs-root/
+$ scp -P 2222 ./squashfs-root.tar.gz root@127.0.0.1:/root
+
+
+extract the tarball on the guest MIPS VM:
+
+root@debian-mips:~# ls
+squashfs-root.tar.gz
+root@debian-mips:~# tar zxf squashfs-root.tar.gz
+root@debian-mips:~#
+Inatll /proc，/dev and /sys and use chroot to enter the firmware file system：
+
+![image](uploads/7550d24729626f680eca7c1e7d764e6e/image.png)
+
+5.Starting the device's service
+Most embedded Linux devices have startup scripts in /etc/init.d/ that will launch services and perform configuration.
+
+# `/etc/init.d/rcS`