from stock to cyanogenmod: the sony ericsson case

FROM STOCK TO CYANOGENMOD:

THE SONY ERICSSON CASEDROIDCON INDIA | NOVEMBER 19, 2011

DIOGO FERREIRA | [email protected] | @DEFER

Saturday, November 19, 11

mailto:[email protected]

mailto:[email protected]

INTRODUCTION


INTRODUCTION

OEM DEVICES RUN SLIGHTLY MODIFIED VERSIONS OF ANDROID

SPORTING FANCY FEATURES AND PERIPHERALS

ADDING UI CUSTOMIZATIONS


INTRODUCTION




CYANOGENMOD SUPPORTS MANY DEVICES ACROSS DIFFERENT HARDWARE PLATFORMS


INTRODUCTION




CYANOGENMOD SUPPORTS MANY DEVICES ACROSS DIFFERENT HARDWARE PLATFORMS

GET CM!

REPO INIT -U GIT://GITHUB.COM/CYANOGENMOD/ANDROID.GIT -B GINGERBREAD

REPO SYNC -J4


THE RECOVERYPART ONE


PRELIMINARIES


PRELIMINARIES

KEEP A COPY OF THE STOCK SYSTEM FILES

ADB PULL /SYSTEM IS ENOUGH

THESE WILL BE NEEDED LATER ON!


PRELIMINARIES

KEEP A COPY OF THE STOCK SYSTEM FILES

ADB PULL /SYSTEM IS ENOUGH

THESE WILL BE NEEDED LATER ON!

BE FEARLESS, IT IS USUALLY VERY HARD TO BRICK A DEVICE


WE NEED A RECOVERY!


WE NEED A RECOVERY!

BACKUP THE ORIGINAL ROM


WE NEED A RECOVERY!


GO BACK TO IT ANYTIME


WE NEED A RECOVERY!



ENABLES YOU TO ACTUALLY FLASH

CM


WE NEED A RECOVERY!



ENABLES YOU TO ACTUALLY FLASH

CM

BUT YOU NEED A DEVICE REPOSITORY TO COMPILE IT


GETTING THINGS GOING



WE HAVE YOU COVERED!




BUILD/TOOLS/DEVICE/MKVENDOR.SH <MANUFACTURER> <DEVICE> /PATH/TO/YOUR/BOOT.IMG





BUILD/TOOLS/DEVICE/MKVENDOR.SH SEMC ANZU BOOT.IMG






WHERE DO I GET THE BOOT IMAGE?







DUMP_IMAGE BOOT /SDCARD/BOOT.IMG







DUMP_IMAGE BOOT /SDCARD/BOOT.IMG

YOU NOW HAVE YOUR BAREBONES DEVICE REPOSITORY OVER AT MANUFACTURER/DEVICE


BUILDING A RECOVERY IMAGE

. BUILD/ENVSETUP.SH

LUNCH FULL_<DEVICE>-ENG

LUNCH FULL_ANZU-ENG

MAKE -J4 RECOVERYIMAGE

YOU WILL HAVE A RECOVERY IMAGE IN OUT/TARGET/PRODUCT/<DEVICE>/RECOVERY.IMG


HOW DO I RUN IT?


HOW DO I RUN IT?USUALLY:

FLASH_IMAGE RECOVERY RECOVERY.IMG




RARELY:

FASTBOOT FLASH RECOVERY RECOVERY.IMG




RARELY:

FASTBOOT FLASH RECOVERY RECOVERY.IMG

IN MY CASE:

FASTBOOT BOOT RECOVERY RECOVERY.IMG

FOR SONY ERICSSON, THERE IS NO DEDICATED RECOVERY PARTITION!


AND THEN THERE WAS A RECOVERY



OR WAS THERE?



OR WAS THERE?

SONY ERICSSON WAS THE FIRST TO

USE 32-BIT FRAMEBUFFERS

RECOVERY CODE NEEDED TO BE ADAPTED

CHANGES GATHERED FROM

CODEAURORA FORUM


THE FIRST BOOTPART TWO


WHERE TO START?


WHERE TO START?YOUR PREVIOUSLY CREATED DEVICE REPOSITORY!



BOARDCONFIG.MK

FILL IN THE BLANKS! THE BUILD SYSTEM NEEDS TO KNOW YOUR DEVICE

THERE IS PROBABLY A SIMILAR DEVICE IN THE TREE, USE IT!



BOARDCONFIG.MK

FILL IN THE BLANKS! THE BUILD SYSTEM NEEDS TO KNOW YOUR DEVICE

THERE IS PROBABLY A SIMILAR DEVICE IN THE TREE, USE IT!

FOR THE SONY ERICSSON ANZU:

TARGET_BOARD_PLATFORM := MSM7X30

TARGET_CPU_ABI := ARMEABI-V7A

...


WHERE TO START?


WHERE TO START?DEVICE_<DEVICE>.MK



TELL THE SYSTEM WHAT TO COMPILE!




DIFFERENT DEVICES HAVE DIFFERENT REQUIREMENTS





FOR A PRELIMINARY BOOT YOU SHOULD BE OK USING THE DEFAULTS






BUT NOTHING WILL WORK







BUILD IT!







BUILD IT!

LUNCH FULL_<DEVICE>.MK







BUILD IT!

LUNCH FULL_<DEVICE>.MK

MAKE -J4 OTAPACKAGE


THE FUN STARTS!


PLATFORM SUPPORTPART THREE


WHAT ABOUT IT?ANDROID NEEDS TO KNOW HOW TO TALK TO YOUR HARDWARE

ANDROID FRAMEWORK / USERSPACE

SENSORS AUDIO DISPLAY ...

KERNEL

HARDWARE


ADDING PLATFORM SUPPORT



USUALLY YOU DON’T NEED TO, CM ALREADY SUPPORTS:

OMAP3/4, TEGRA 2, QUALCOMM 7X30/8X60/8K



USUALLY YOU DON’T NEED TO, CM ALREADY SUPPORTS:

OMAP3/4, TEGRA 2, QUALCOMM 7X30/8X60/8K

IF YOU DO, GET THEM FROM REFERENCE BOARD REPOS:

QUALCOMM: HTTP://WWW.CODEAURORA.ORG

TI: HTTP://WWW.OMAPZOOM.ORG

NVIDIA: HTTP://NV-TEGRA.NVIDIA.COM

LINARO: HTTP://WWW.LINARO.ORG


http://www.linaro.org

http://www.linaro.org

ADDING PLATFORM SUPPORT: CAVEATS


ADDING PLATFORM SUPPORT: CAVEATS BEWARE: IT SHOULD BE CONTAINED



YOU MUST ENSURE IT WILL NOT BREAK OTHER DEVICES




IF YOU REALLY MUST CHANGE THINGS OUTSIDE THE INTERFACE LAYERS:





BOARD CONFIG OPTION + #IFDEF





BOARD CONFIG OPTION + #IFDEF

SYSTEM PROPERTY + ALTERNATING BRANCHES IN THE JAVA SIDE


HARDWARE ABSTRACTION LAYERS



THEY LIVE BETWEEN THE FRAMEWORK AND THE KERNEL




LIGHTS, GPS, GRALLOC + OVERLAY, AUDIO, CAMERA, SENSORS





A SET OF WELL-DEFINED APIS






IF VENDORS FOLLOW THEM, WE CAN JUST USE PROPRIETARY HALS







IF THEY DO NOT, IT WILL BE A MIX OF:








REFERENCE DESIGNS








REFERENCE DESIGNS

INTUITION








REFERENCE DESIGNS

INTUITION

REVERSE ENGINEERING


OUR HEADER VENDOR’S HEADER

CLASS CAMERAHARDWAREINTERFACE {VOID STARTCAMERA();VOID STOPCAMERA();

}

CLASS CAMERAHARDWAREINTERFACE {VOID STOPCAMERA();VOID STARTCAMERA();

}

SOLVING HAL API BREAKS




}


}


0X040X08




}


}


0X040X08

0X040X08




}


}


0X040X08

0X040X08

CAMERAHARDWAREINTERFACE *HW = GETHARDWARE(); HW = 0X38HW->STARTCAMERA(); (*(0X38+0X04))();


#@#”!#$!”””!!!!!


SOLVING HAL BREAKS


SOLVING HAL BREAKS

COMPARE A KNOWN SOURCE WITH THE BINARY BLOB

NOTE DOWN THE OFFSETS FOR METHOD CALLS

ORDER THE HEADER APPROPRIATELY


SOLVING HAL BREAKS

COMPARE A KNOWN SOURCE WITH THE BINARY BLOB

NOTE DOWN THE OFFSETS FOR METHOD CALLS

ORDER THE HEADER APPROPRIATELY

VENDORS COULD EASILY AVOID BREAKING HALS:

ADD METHODS TO THE END OF HEADERS

STOP REORDERING THEM!


FOR SONY ERICSSON


FOR SONY ERICSSON

MOST OF THE HALS WERE GREAT

BUT THEY BROKE THE CAMERA API

REORDERING THE METHODS AFTER REVERSE ENGINEERING FIXED IT


FOR SONY ERICSSON

MOST OF THE HALS WERE GREAT

BUT THEY BROKE THE CAMERA API

REORDERING THE METHODS AFTER REVERSE ENGINEERING FIXED IT

ONCE THE HEADER IS REVERSED, WE ADD IT TO THE DEVICE REPOSITORY

HEADERS ARE COMMON FOR ALL DEVICES

IF YOU CHANGE THE GLOBAL ONE, THINGS WILL BREAK.


FOR SONY ERICSSON

8255 SOC FROM QUALCOMM

7X30 FAMILY, ALREADY SUPPORTED IN CYANOGENMOD

CUSTOM LIGHTS HAL

REMEMBER THE 32-BIT DISPLAY? GRALLOC DID TOO

PRECOMPILED BLOBS FOR GPS, SENSORS AND CAMERA

SOMETIMES YOU JUST DON’T HAVE A CHOICE


CONCLUSIONS


CONCLUSIONS

PORTING A DEVICE IS NOT IMPOSSIBLE


CONCLUSIONS


YOU CAN’T BREAK OTHER DEVICES

THIS IS REALLY HARD!


CONCLUSIONS




IF THERE IS PLATFORM SUPPORT FOR YOUR DEVICE, SUPPORT CAN BE ADDED IN A FEW HOURS

SOMETIMES AS FEW AS 15 MINUTES


CONCLUSIONS




IF THERE IS PLATFORM SUPPORT FOR YOUR DEVICE, SUPPORT CAN BE ADDED IN A FEW HOURS

SOMETIMES AS FEW AS 15 MINUTES

ALWAYS CHECK OUT SIMILAR DEVICES

THE SAME SOC MEANS IT WILL BE SIMILAR


YOUR QUESTIONSPART FOUR


from stock to cyanogenmod: the sony ericsson case

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