presentation at Kernel/KVM tankentai

1. jslinux
Linux emulator by Javascript
Hiro Yoshioka
YLUG – Yokohama Linux Users Group
@hyoshiok
hyoshiok at gmail.com
http://d.hatena.ne.jp/hyoshiok

2.  http://bellard.org/jslinux/
 What is it?
 Linux Emulator
 It is written in Javascript
 Developed by Fabrice Bellard
 QEMU
 2700 billion decimal digits of Pi
 FFMPEG
 TCC, QEmacs, and more

3. Javascript PC Emulator
 This PC emulator is written in Javascript.
 32 bit x86 compatible CPU
 8259 Programmble Interrupt Controller
 8254 Programmble Interrupt Timeer
 16450 UART
 Real Time Clock

4. CPU Emulation
 QEMU (developed by Fabrice Bellard)
 Some restrictions
 No FPU/MMX/SSE
 No segment limit and right checks when accessing
memory.
 No CS/DS/ES/SS segment overrides.
 missing instruction (BCD operations, BOUND, …)
 No single stepping
 No real mode
 No 16 bit protected mode

5. Device
 No synchronization between PIT and the real
time
 Clipboard device /dev/clipboard – exchange of
data between the emulator andf out side world.

6. Linux Distribution
 2.6.20 linux kernel
 Buildroot
 Busybox
 Tinycc
 qemacs

7. Javascript
 V8 is slower than Jaeger Monkey

8. What's the use?
 Benchmarking
 Learning to use command line Unix