Rockie's Android Porting Guide（4）——Add SD card to your system

Rockie's Android Porting Guide（4）——Add SD card to your system

from:
http://hi.baidu.com/aokikyon/blog/item/a806363b3572e8e114cecb14.html
Rockie's Android Porting Guide（4）——Add SD card to your system

Rockie Cheng

Andorid use vold to manage SD card and it is easy to use.

But I meet many troubles and finally find that the real problem is in the Linux Kernel.

Thanks to the Android Mail List.

Part I (kernel)

(1)make sure thus kernel configuration in MMC driver

CONFIG_MMC=y

# CONFIG_MMC_DEBUG is not set

CONFIG_MMC_UNSAFE_RESUME=y

# CONFIG_MMC_EMBEDDED_SDIO is not set

CONFIG_MMC_PARANOID_SD_INIT=y

#

# MMC/SD Card Drivers

#

CONFIG_MMC_BLOCK=y

CONFIG_MMC_BLOCK_BOUNCE=y

# CONFIG_MMC_BLOCK_PARANOID_RESUME is not set

# CONFIG_SDIO_UART is not set

# CONFIG_MMC_TEST is not set

#

# MMC/SD Host Controller Drivers

#

CONFIG_MMC_SDHCI=y

(2)Disable this option

General Setup -> Create deprecated sysfs layout for older userspace tools

Before I did this,vold showed a lot of trouble.

And ,my media_path is not right

media_path /devices/platform/s3c-sdhci.0/mmc_host:mmc0<--my path before turn off that option

media_path /devices/platform/s3c-sdhci.0/mmc_host/mmc0 <--this is the right one

Vold may be unhappy to accept my old path,and it didn't work.

D/vold ( 42): Accepted connection from framework

D/vold ( 42): dispatch_cmd(send_ums_status):

D/vold ( 42): dispatch_cmd(mount_volume:/sdcard):

E/vold ( 42): Cannot start volume '/sdcard' (volume is not bound)

D/MountListener( 59): handleEvent volume_nomedia:/sdcard

D/MountListener( 59): handleEvent ums_disabled

D/MountListener( 59): handleEvent ums_disconnected

(3) rebuild your linux kernel

PART II(android system)

(1) creat a vold.conf in build/target/board/idea6410

## vold configuration file for idea6410

volume_sdcard {

## This is the direct uevent device path to the SD slot on the device

media_path /devices/platform/s3c-sdhci.0/mmc_host/mmc0

media_type mmc

mount_point /sdcard

ums_path /devices/platform/usb_mass_storage/lun0

}

(2)add those below to AndroidBoard.mk

include $(CLEAR_VARS)

LOCAL_MODULE_CLASS := ETC

LOCAL_MODULE := vold.conf

LOCAL_SRC_FILES := $(LOCAL_MODULE)

include $(BUILD_PREBUILT)

(3)rebuild the system and check init.rc

service vold /system/bin/vold

socket vold stream 0660 root mount

(4)enjoy

D/vold ( 42): Accepted connection from framework

D/vold ( 42): dispatch_cmd(send_ums_status):

D/vold ( 42): dispatch_cmd(mount_volume:/sdcard):

I/vold ( 42): Evaluating dev '/devices/platform/s3c-sdhci.0/mmc_host/mmc0/mmc0:e624/block/mmcblk0' for mountable filesystems for '/sdcard'

D/MountListener( 61): handleEvent volume_unmounted:/sdcard

D/MountListener( 61): handleEvent ums_disabled

D/MountListener( 61): handleEvent ums_disconnected

D/MountListener( 61): handleEvent volume_checking:/sdcard

Rockie Cheng

阿虚

I//system/bin/fsck_msdos( 1656): ** /dev/block//vold/179:1

I//system/bin/fsck_msdos( 1656): ** Phase 1 - Read and Compare FATs

I//system/bin/fsck_msdos( 1656): Attempting to allocate 30 KB for FAT

I//system/bin/fsck_msdos( 1656): Attempting to allocate 30 KB for FAT

I//system/bin/fsck_msdos( 1656): ** Phase 2 - Check Cluster Chains

I//system/bin/fsck_msdos( 1656): ** Phase 3 - Checking Directories

I//system/bin/fsck_msdos( 1656): ** Phase 4 - Checking for Lost Files

I//system/bin/fsck_msdos( 1656): 1 files, 122856 free (15357 clusters)

I/logwrapper( 1656): /system/bin/fsck_msdos terminated by exit(0)

D/vold ( 1656): Filesystem check completed OK

E/vold ( 1656): vfat filesystem mount of 179:1 failed (-1)

D/MountListener( 1671): handleEvent volume_damaged:/sdcard

搞定了！

open option:

kernel->file system->DOS/FAT/NT Filesystems ---> MSDOS & VFAT