• FPU를 쓰거나 쓰지 않는, 빠른 실수 연산(floating point) 성능
• soft 와 hardfloat 코드의 혼용 가능
• 이전에 사용되어지던 것과 같이 구조체 팩킹(packing)이 고통스럽지 않습니다.
• 다른 툴들과의 더 나은 호환성(compatibility)
• 더 효율적인 syscall 관례(convention). (http://www.arm.linux.org.uk/developer/patches/viewpatch.php?id=3105/4)
  
  

long ftruncate64(unsigned int fd, loff_t length); 의 예:

기존 ABI:
- put fd into r0 (fd를 r0로 넣음)
- put length into r1-r2 (길이를 r1-r2로 넣음)
- 커널 호출을 위해서 "swi #(0x900000 + 194)" 사용.

새로운 ARM EABI:
- put fd into r0 (fd를 r0로 넣음)
- put length into r2-r3 (skipping over r1) (길이를 r2-r3로 넣음. r1은 무시)
- put 194 into r7 (194를 r7로 넣음)
- use "swi 0" to call the kernel (커널을 호출하기 위해서 "swi 0" 사용)

• 기존 ABI

$ arm-softfloat-linux-gnu-objdump -x t7-demo | grep private
private flags = 202: [APCS-32] [FPA float format] [software FP] [has entry point]

$ file t7-demo
t7-demo: ELF 32-bit LSB executable, ARM, version 1 (ARM), 
for GNU/Linux 2.4.3, dynamically linked (uses shared libs), 
for GNU/Linux 2.4.3, stripped

• ARM EABI

$ arm-softfloat-linux-gnueabi-objdump -x t7-demo  | grep private
private flags = 4000002: [Version4 EABI] [has entry point]

$ file t7-demo
t7-demo: ELF 32-bit LSB executable, ARM, version 1 (SYSV), 
for GNU/Linux 2.6.14, dynamically linked (uses shared libs), 
for GNU/Linux 2.6.14, stripped

• Dianne Hackborn worked for the BeOS explains briefly at osnews.com.
  http://osnews.com/story/13674/Introduction-to-OpenBinder-and-Interview-with-Dianne-Hackborn/
  
  
• Documentation
  http://www.angryredplanet.com/~hackbod/openbinder/docs/html/index.html
  
  
• Source code
  http://www.angryredplanet.com/~hackbod/openbinder/openbinder-12-28-2005.tar.gz
  
  

• 프레임 버퍼 정보 초기화

struct fb_info *fbinfo;
...
fbinfo->fix.ypanstep	= 1;
fbinfo->var.yres_virtual    = gm->lcd.yres * 2;
fbinfo->fix.smem_len        =	(gm->lcd.xres *
                                gm->lcd.yres *
                                gm->lcd.bpp / 8) * 2;

• 프레임 버퍼 메모리 할당

struct mvfb_info *fbi;
...
fbi->map_size = PAGE_ALIGN(fbi->fb->fix.smem_len + PAGE_SIZE);
fbi->map_cpu  = dma_alloc_writecombine(fbi->dev, fbi->map_size,
                                       &fbi->map_dma, GFP_KERNEL);

• fb_pan_display 함수 후킹 구현

static int mvfb_pan_display(struct fb_var_screeninfo *var, struct fb_info *fb)
{
...
}

static struct fb_ops mvfb_ops = {
        .owner		= THIS_MODULE,

        .fb_check_var	= mvfb_check_var,
        .fb_set_par	= mvfb_set_par,	
        .fb_setcolreg	= mvfb_setcolreg,
        .fb_blank	= mvfb_blank,
        .fb_pan_display = mvfb_pan_display,

        .fb_fillrect	= cfb_fillrect,
        .fb_copyarea	= cfb_copyarea,
        .fb_imageblit	= cfb_imageblit,

        .fb_mmap	= mvfb_mmap,	
};

$ adb shell

# cat /proc/bus/input/devices
I: Bus=0000 Vendor=0000 Product=0000 Version=0000
N: Name="goldfish-events-keyboard"
P: Phys=
S: Sysfs=/class/inut/input0
U: Uniq=
H: Handlers=kbd mouse0 event0
...
#
# cat /proc/bus/input/handlers
N: Number=0 Name=kbd
N: Number=1 Name=mousedev Minor=32
N: Number=2 Name=evdev Minor=64
#

• 키패드

struct input_event {
        struct timeval time;
        unsigned short type;
        unsigned short code;
        unsigned int value;
};

/*
 *  Key Layout       Scancode Table
 *
 *   1  2  3        0x1  0x10  0x100
 *   4  5  6        0x2  0x20  0x200
 *   7  8  9        0x4  0x40  0x400
 *   *  0  #        0x8  0x80  0x800
 */

static unsigned short android_keycode[] = {
        /*
         *  0x66 0x67 0x9e	Home  Up   Back
         *  0x69 0xe8 0x6a	Left  Ok   Right
         *  0xe7 0x6c 0x6b	Send  Down Hangup
         *  0xe5		Menu       just_distinction_for_private
         */
        KEY_HOME,         KEY_UP,       KEY_BACK,
        KEY_LEFT,         KEY_REPLY,    KEY_RIGHT,
        KEY_SEND,         KEY_DOWN,     KEY_END,
        KEY_KBDILLUMDOWN, KEY_RESERVED, KEY_PLAY
};

...
keycode = translate_keycode(scancode);
...
input_event(keydev->input, EV_KEY, keycode, KEY_PRESSED);
or
input_event(keydev->input, EV_KEY, keycode, KEY_RELEASED);
...

• 터치 스크린
  
  

# cat /proc/bus/input/devices
I: Bus=0000 Vendor=0000 Product=0000 Version=0000
N: Name="MVT7 KEYPAD"
P: Phys=
S: Sysfs=/class/input/input0
U: Uniq=
H: Handlers=kbd event0 evbug
B: EV=f
...

I: Bus=0000 Vendor=0000 Product=0000 Version=0000
N: Name="TSC2007 Touchscreen"
P: Phys=0-0090/input0
S: Sysfs=/class/input/input1
U: Uniq=
H: Handlers=event1 evbug
B: EV=b
B: KEY=400 0 0 0 0 0 0 0 0 0 0
B: ABS=1000003

# cat /proc/bus/input/handlers
N: Number=0 Name=kbd
N: Number=1 Name=evdev Minor=64
N: Number=2 Name=evbug

• ramdisk.img
• system.img
• userdata.img
  
  

$./arm-softfloat-eabi.sh

• 필수적인 부분

...
CONFIG_PANIC_TIMEOUT=0
CONFIG_AEABI=y
CONFIG_OABI_COMPAT=y
CONFIG_BINDER=y
CONFIG_LOW_MEMORY_KILLER=y
...

• 필요에 따른 부분

...
# CONFIG_ANDROID_GADGET is not set
# CONFIG_ANDROID_RAM_CONSOLE is not set
# CONFIG_ANDROID_POWER is not set
# CONFIG_ANDROID_LOGGER is not set
...

$ gzip -cd ramdisk.img > ramdisk
$ cpio -iv -F ramdisk

# adb push busybox .

# adb shell

# chmod +x /busybox
# busybox tar -c /data.tar /data
# busybox tar -c /system.tar /system
# exit

# adb pull /data.tar .
# adb pull /system.tar .

...
startup {
        ...
#       qemu-init {
#           exec /etc/qemu-init.sh
#       }
}
...

#!/bin/sh
mount -t yaffs /dev/block/mtdblock5 /mnt
mount --bind /mnt/data   /data
mount --bind /mnt/system /system

# data folder is owned by system user on emulator. Fix 777 to other.
chmod 777 /data
#chmod 777 /system

export PATH=/system/sbin:/system/bin:/sbin/usr/local/bin
export LD_LIBRARY_PATH=/system/lib

export ANDROID_BOOTLOGO=1
export ANDROID_ROOT=/system
export ANDROID_ASSETS=/system/app
export EXTERNAL_STORAGE=/sdcard
export ANDROID_DATA=/data
export DRM_CONTENT=/data/drm/content

/init &

...
export TSLIB_CONSOLEDEVICE=none
export TSLIB_FBDEVICE=/dev/fb0
export TSLIB_TSDEVICE=/dev/input/event1
export TSLIB_CALIBFILE=/etc/pointercal
export TSLIB_CONFFILE=/etc/ts.conf
export TSLIB_PLUGINDIR=/lib/ts

export LD_PRELOAD=/lib/libts.so:/lib/ts/pthres.so
...

# cd /
# . /android/run.sh
yaffs: dev is 32505861 name is "mtdblock5"
yaffs: passed flags ""
yaffs: Attempting MTD mount on 31.5, "mtdblock5"
yaffs: auto selecting yaffs2
# init: HOW ARE YOU GENTLEMEN
init: reading config file
init: device init
init: mtd partition -1,
init: mtd partition 0, "l1boot"
init: mtd partition 1, "u-boot"
init: mtd partition 2, "params"
init: mtd partition 3, "kernel"
init: mtd partition 4, "ramdisk"
init: mtd partition 5, "rootfs"
sh: can't access tty; job control turned off
# binder_open(c394bcc8 c3c731a0) (pid 1577) got c3e48000
binder_open(c394bcc8 c3cd8dc0) (pid 1616) got c319f000
binder_open(c394bcc8 c3cd8ac0) (pid 1673) got c3d10000
binder_open(c394bcc8 c3cd8940) (pid 1680) got c0e19000
binder_open(c394bcc8 c3cd88c0) (pid 1691) got c2fa0000
binder_open(c394bcc8 c3d174a0) (pid 1592) got c25b8000
binder_release(c394bcc8 c3cd88c0) (pid 1691) pd c2fa0000
#

• /dev 상에 eac 디바이스 파일을 만들지 마세요. 그 것은 qemu상의 오디오를 위한 것입니다. 만약 있다면 시작 절차(start up sequence)는 사운드 디바이스에 어떤 데이터를 쓰는 것을 끝마치기 위해서 영원히 기다릴 것입니다.
• 수동 시작(manual startup) 대신에 안드로이드 init 바이너리를 사용하세요. 수동 시작은 안드로이드 패치가 필요합니다. 그 경우 시작 절차는 /sys/android_power/acquire_partial_wake_lock에 접근하고 기다릴 것입니다.
  
  

• AndroidManifest.xml
• classes.dex
• resources.arsc
• res 디렉토리
  
  

• 노키아의 N810 제품(arm1136jf-s) 상의 안드로이드 플랫폼
  
  
  
• Android Platform on arm1136jf-S for another CE Product.
  Upload new Attachment "fi.armadillo500.android1.0.jpg"
  
  

• 안드로이드 메인 페이지 : http://code.google.com/android/
• 데비안(Debian) ARM EABI 위키 : http://wiki.debian.org/ArmEabiPort
• 시스템 콜 규약 : http://www.arm.linux.org.uk/developer/patches/viewpatch.php?id=3105/4
• Codesourcery의 FAQ : https://support.codesourcery.com/GNUToolchain/kbentry32
• OpenBinder를 위한 Dianne Hackborn 인터뷰 : http://osnews.com/story/13674/Introduction-to-OpenBinder-and-Interview-with-Dianne-Hackborn/
• OpenBinder 문서 : http://www.angryredplanet.com/~hackbod/openbinder/docs/html/index.html
• OpenBinder 소스 코드 : http://www.angryredplanet.com/~hackbod/openbinder/openbinder-12-28-2005.tar.gz
• Crosstool : http://www.kegel.com/crosstol/
• Crosstool EABI 패치 : http://sources.redhat.com/ml/crossgcc/2006-12/msg00076.html
• Codesourcery : http://www.codesourcery.com
• Benno의 블로그 : http://benno.id.au
• Android 패치 : http://benno.id.au/blog/2007/11/21/android-neo1973
• Static Busybox : http://benno.id.au/blog/2007/11/14/android-busybox
• Static Strace : http://benno.id.au/blog/2007/11/18/android-runtime-strace
• Dex 파일 형식 : http://www.retrodev.com/android/dexformat.html
• Android SDK 설치 : http://code.google.com/android/intro/installing.html
• Eclipse IDE : http://www.eclipse.org/downloads/
• JDK SE : http://java.sun.com/javase/downloads/index.jsp
• 2008 Korea Android Summit의 발표