Beagle Board Project Hui Keji

8/2/2019 Beagle Board Project Hui Keji

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BeagleBoard Fast Boot

Hui ChenKeji Ren

Dec 10th, 2009

EE382N-4 Project


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Outline Motivation

Objectives

Hardware of BeagleBoard

Techniques in optimizing boot time

Boot time result

Conclusions

Future work

Live demo

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Motivation:Why Faster Boot Time?

Boot time definition:

Time from turning on power to a shell

Impact the first perception an end

Critical to obtain a positive end us

Save power

elcome prompt (or a GUI).

ser has of the product

r experience

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Objectives

Optimize software in BeagleBoard

1. bootloader

2. Linux Kernel

3. user-space applications

Achieve a 5-second fast boot time

was about 15 seconds.

for speed

in BeagleBoard. Original boot time

EE382N-4 Project


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BeagleBoard Har

OMAP 3530 Processor

600 MHz ARM Cortex-A8 with NEO

256MB on-chip RAM

256MB NAND Flash

Peripheral I/Os

DVI-D, SD/MMC+, S-Video, USB 2.

Stereo In/Out, RS232 Serial

Power

USB or 5V DC

ware

N

0

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Serial Cable SetuWe made a customized Null Modem ca

PC's serial port.

ble to connect BeagleBoard to

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Boot Sequence

EE382N-4 Project


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Strategies Load from NAND Flash

X-loader/u-boot loading speed in SVC3NANDs block size is 128 KB per readin

blocks (instead of 7 blocks originally).

Remove unnecessary initialization, i

We modified u-boot to

1. Embed configuration environments i

2. Turn off Kernel CRC check

3. Remove Kernel relocation in u-boot (

cpu mode: NAND = 1MB, MMC = 500KB/sg. We modified x-loader to only load 2

ntegration check and data movement

to u-boot (instead of reading from NAND)

skip the 64-byte header of Linux image)

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Reduce user response time

1. Set bootdelay to zero in u-boot (so us

2. Turn off serial output by passing 'quiet'

Strategies (cont.

Reduce code size

We used '-Os -mthumb' flag to compile a

user-space applications). Code size win

Remove unnecessary functionalities

We compiled a 1.2MB 2.6.29 Kernel with

for our Pegasus USB Ethernet adapter.

r can't interrupt u-boot)

parameter to Kernel

ll code (x-loader, u-boot, kernel and

hands down.

in Kernel and avoid modules

USB, network, ext3/JFFS2 and a driver

EE382N-4 Project


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User-space optimization

1. Build Linux rootfs from scratch. By ca

reduced total size of rootfs to about 780

2. Minimize init script: disable syslogd a

Strategies (cont

scripts.

Choose faster file system

Ext3 needs journal daemon whose loadi

Instead we use Ext2.

We didn't choose JFFS2 on NAND due

refully tuning uclibc and busybox, we

B without losing desired features.

d klogd, remove unused tty and rc

.)

ng time varies (can be over one second).

o the buggy Linux driver.

EE382N-4 Project


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Boot Time Result[ 0.000005] < 0.000005> Texas Instruments X-Loader 1.4.2 (De

[ 0.003808] < 0.003803> Loading u-boot.bin from nand[ 0.228279] < 0.224471>

[ 0.228349] < 0.000070>

[ 0.232136] < 0.003787> U-Boot 2009.06-rc2-dirty (Dec 08 200

[ 0.232178] < 0.000042>

[ 0.239877] < 0.007699> OMAP3530-GP ES3.0, CPU-OPP2 L3-16

[ 0.239932] < 0.000055> OMAP3 Beagle board + LPDDR/NAND

[ 0.239959] < 0.000027> DRAM: 256 MB

[ 0.251298] < 0.011339> NAND: 256 MiB

0.259473 < 0.008175> In: serial

BoLin

[ 0.259526] < 0.000053> Out: serial[ 0.259545] < 0.000019> Err: serial

[ 0.263444] < 0.003899> Board revision C

[ 0.263485] < 0.000041> Hit any key to stop autoboot: 0

[ 0.267380] < 0.003895>

[ 0.271382] < 0.004002> NAND read: device 0 offset 0x280000,

[ 1.551374] < 1.279992> 1191936 bytes read: OK

[ 1.555640] < 0.004266> ## Booting kernel from Legacy Image[ 1.561426] < 0.005786> Loading Kernel Image ... OK

[ 1.561455] < 0.000029> OK

[ 1.565348] < 0.003893>

[ 1.565392] < 0.000044> Starting kernel ...

[ 1.565410] < 0.000018>

[ 1.895363] < 0.329953> Uncompressing Linux.....................

kernel.[ 2.923280] < 1.027917>

Please press Enter to activate this console.

$ piTotpro

8 2009 - 23:36:42)

- 23:47:30)

MHz

t time was measured by using ptx_ts script from hostx PC:

size 0x123000

t 80007fc0 ...

......................................................... done, booting the

cocom --b 115200 -d 8 /dev/ttyS0 | ptx_ts 'Texas'l boot time from power on to terminal welcome

mpt is 2.92 seconds without network.

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Boot time compo

Loading u-boot from NAND

Loading Kernel from NAND

xecu on x- oa er + u- oo

Uncompressing Kernel

Execution (Kernel)

Mounting Memory Card

User-space applications

Total

ition

Delay (second)

0.22

1.28

.

0.73

0.29

0.27

0.07

2.92

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Conclusions

We achieved shorter boot time than we exp

We established a website with wiki pages,

http://code.google.com/p/swiftbeagle/

We obtained a good understanding on

1. BeagleBoard hardware

2. What are required in writing a boot

detecting machine ID and passingbootloader called S-Boot. However, d

phase and Kernel stalls after uncompre

3. Patching Kernel source

4. Building a Linux rootfs from scratch

5. Compiler optimization techniques (w

Sourcery's latest ARM gcc compiler/libr

ected.

ll modified source code and binaries:

loader (such as disabling MMU/dcache,

TAGS to Kernel). We wrote our ownvelopment of S-Boot is still in debugging

ssing itself.

believe we found a defect in Code

ry)

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Future Work: What Wou

0.5 second boot can be realized by utilizing

NAND driver, uncompressed Kernel and fas

Delay

Loading u-boot from NAND

Loading Kernel from NAND

Execution (x-loader + u-boot)

Uncompressing Kernel

Execution (Kernel)

Mounting Memory Card

User-space applications

Total

d Be Different?

XIP(Execution in Place), faster

er FS(JFFS2 on MTD).

(second) Optimization to use

.22 XIP/driver

1.28 XIP/driver

.06

.73 uncompressed Kernel

.29

.27 faster FS/driver

.07

.42

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Demo Time

EE382N-4 Project

Beagle Board Project Hui Keji

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