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Similar a Rloader, alternative tech to achieve fast boot time for ARM Linux
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Rloader, alternative tech to achieve fast boot time for ARM Linux
- 1. Connect your device to application
- 2. Rloader, Alternative technology to achieve fast boot time for ARM Linux Matt Hsu <matt@0xlab.org>
- 3. Agenda Motivation Boot Time Measurement Reduction Approach Hibernation Based Technologies Rloader Demo Summary Q&A
- 4. Movitation
- 5. Why Boot Time? Define boot time, please Power saving User experiences Android's boot time is especially painful Devices Tablet In-vechile system TV Smart Phone Camera
- 6. We Are Not Alone Quick boot Ubiqutous Improving meego boot-up time Hiroshi DOYU, Nokia Sotware Architect Boosting up embedded Linux device: experience on Linux-based smarphone Samsung Electronics Co. Ltd. Swap-before-hibernate: A fast-on algorithm at OS level Shi-wu Lo, OS Lab, CCU
- 9. Kernel space Kernel parameter printk.time =1 linux-2.6/scripts/show_delta Ftrace ftrace=initcall Initcall Enable BOOT_TRACER config ./scripts/bootgraph.pl boot_time >out.svg initcall_debug
- 10. User Space Bootchart http://www.bootchart.org/ cat /proc/uptime 2012.39 512.64 grabserial http://elinux.org/Grabserial
- 11. Hardware Approach External instrument Scope Logic Analyzer Hardware timer count Resolution is dependent on your clock source ETM (Embedded Trace Microcell) Need assisted software such as TRACE32/OpenOCD New feature in ARM Cortex seies
- 14. Bootloader Minimal bootloader Qi bootloader zboot, linux boot directly Enable I-cache Copy kernel into base + 0x2000000 offset DMA-capable copy Multi-block read (MMC)
- 15. Kernel Kernel parameter quiet Preset LPJ Loop per jiffy Deferred initcall include/linux/init.h arch/arm/kernel/vmlinux.lds Compressed kernel UCL XZ
- 16. Userland Optimize linker and loader time Specific linker option Parallelize rc script Application specific optimization Hibernation based technologies
- 17. Hibernate-Based Technologies Swsusp, aka software suspend Swsusp2 (TuxOnICE)
- 18. Swsusp Natviely support in x86 Based on work by TI, Teerth Reddy https://patchwork.kernel.org/patc h/96442/ Nokia, Hiroshi DOYU https://lists.linux- foundation.org/pipermail/linux- pm/2010-June/027422.html Start hibernation echo disk >/sys/power/state
- 19. Swsusp2/TuxOnICE Not support in main line kernel Provides many features Compression of images Readhead multiple thread I/O drop pagecache Hbernation trigger eho 1 >/sys/power/tuxonice/do_hib ernation
- 21. Rloader Is Nothing New Do we really need follow normal booting process? The implementation of Rloader could be Bootloader snapshot boot www.elinux.org/images/3/37/Snapshot-boot-final.pdf Custom kernel Kernel with software resume support Different hibernation images make difference user scenario
- 22. Booting Process Normal booting Boottloader Kernel Init init.rc, platform-specific rc init Kernel as Rloader Bootloader Minimal device Restore init Init process Bootloader as Rloader Bootloader Restore init process
- 23. Make ARM Hibernated Merge patches swsusp patch from TI/Nokia TOI patches according to your kernel version 'swap out' page as much as possible ARM does not support ACPI Currently, there are patches for ARM Cortex A8/A9 provided
- 24. Hardware/Software Descripton ARM OMAP3 Beagleboard Kernel 2.6.32 with corresponding TOI patch Bootloader Qi 256MB RAM 0xdroid Eclair
- 25. Something before hibernating echo 100 > /proc/sys/vm/swappiness echo -2 > /sys/power/tuxonice/image_size_limit echo 3 >/proc/sys/vm/drop_caches busybox swapon -p 1 /dev/block/mtdX
- 26. Normal Booting Time Diagram 25 seconds GPIO signal of Key-guard event GPIO signal of Power On Reset stepping into kernel
- 27. Hibernation Boot Time Diagram 6 seconds Power On Reset GPIO signal of GPIO signal of stepping into kernel Key-gurad event
- 28. Rloader as Kernel or Bootloader? It's a trade-off between your boot time and management cost Maintainence Once kernel/TOI changes, you need to re-implement Complexicity How to restore pages? Resume point? PC value? Improved room might be limited
- 29. Further Optimization Re-construct initcall stages Try different algorithm out on compressing images http://code.google.com/p/snappy/ Lazy loading Put driver state into hibernation image
- 30. Summary It's still far away from being a product File system inconstency Power failure as hibernation Hardware solution is the sliver bullet? The time of stepping into hibernation is also needed to concern
- 31. Demo
- 34. Sponsored by http://0xlab.org 27 May 2011