|
|
|
### Introduction
|
|
|
|
All Android devices use separate partitions for storing different parts of the entire system. The boot partition consists of the linux kernel, recovery partition contains the recovery binary, system partition contains the device's ROM, data partition contains all user data and cache partition contains some cache data including dalvik-cache.
|
|
|
|
Partition layout files are used to determine where each specific partition, used for Android's internal tools and provide the data to tools like Online Nandroid. The linux kernel reveals this layout in different places at times, but not always. In some instances, if this layout is not revealed, Online Nandroid uses it's own manually created partition layout file at `/system/partitionlayout4nandroid`.
|
|
|
|
|
|
|
|
Example (`/proc/partitions` on a Google Nexus 4):
|
|
|
|
```none
|
|
|
|
major minor #blocks name
|
|
|
|
179 0 15388672 mmcblk0
|
|
|
|
179 1 65536 mmcblk0p1
|
|
|
|
179 2 512 mmcblk0p2
|
|
|
|
179 3 512 mmcblk0p3
|
|
|
|
179 4 2048 mmcblk0p4
|
|
|
|
179 5 512 mmcblk0p5
|
|
|
|
179 6 22528 mmcblk0p6
|
|
|
|
179 7 22528 mmcblk0p7
|
|
|
|
179 8 780 mmcblk0p8
|
|
|
|
179 9 780 mmcblk0p9
|
|
|
|
179 10 780 mmcblk0p10
|
|
|
|
179 11 512 mmcblk0p11
|
|
|
|
179 12 512 mmcblk0p12
|
|
|
|
179 13 512 mmcblk0p13
|
|
|
|
179 14 2048 mmcblk0p14
|
|
|
|
179 15 512 mmcblk0p15
|
|
|
|
179 16 512 mmcblk0p16
|
|
|
|
179 17 512 mmcblk0p17
|
|
|
|
179 18 512 mmcblk0p18
|
|
|
|
179 19 16384 mmcblk0p19
|
|
|
|
179 20 16384 mmcblk0p20
|
|
|
|
179 21 860160 mmcblk0p21
|
|
|
|
179 22 573440 mmcblk0p22
|
|
|
|
179 23 13798400 mmcblk0p23
|
|
|
|
179 24 512 mmcblk0p24
|
|
|
|
179 25 495 mmcblk0p25
|
|
|
|
```
|
|
|
|
|
|
|
|
<br /><br />
|
|
|
|
|
|
|
|
### MTD Based Devices
|
|
|
|
MTD (Memory Technology Device) based devices have `/proc/mtd` populated with the partition layout, by the linux kernel. Thus, no specific partition layout file is required by Online Nandroid, on MTD based devices.
|
|
|
|
|
|
|
|
Example (`/proc/mtd` on a Sony Ericsson Xperia Pro):
|
|
|
|
```none
|
|
|
|
dev: size erasesize name
|
|
|
|
mtd0: 19000000 00020000 "system"
|
|
|
|
mtd1: 00600000 00020000 "appslog"
|
|
|
|
mtd2: 06580000 00020000 "cache"
|
|
|
|
mtd3: 1a400000 00020000 "userdata"
|
|
|
|
mtd4: 00c80000 00020000 "boot"
|
|
|
|
```
|
|
|
|
|
|
|
|
Note: Some buggy kernels may not populate `/proc/mtd` properly. In most such cases, the underlying MTD partitions would also not be revealed by the kernel, thus proving a workaround partition layout virtually useless.
|
|
|
|
|
|
|
|
<br /><br />
|
|
|
|
|
|
|
|
### EMMC Based Devices
|
|
|
|
Few EMMC (Embedded MultiMedia Card) based devices have `/proc/emmc` populated with the partition layout, by the linux kernel. In this case, no specific patch file is required by Online Nandroid. However, this practice is not followed in later devices. Thus, these require patch files. A partition layout file is very similar to `/proc/mtd` or `/proc/emmc` generated by linux kernel. It follows the same format and the same header.
|
|
|
|
Gathering information to produce a partition layout file is trivial. It is sometimes revealed somewhere under the `/sys/devices` by linux kernel. But this is not always the case. ROM and kernel developers, would, most of the time, figure this out and share this information in development threads on forums like XDA. Other times, it is easiest to obtain a copy of recovery.fstab used by stock, CWM, TWRP and other recoveries. This file is present in the recovery ramdisk and thus can be obtained from someone who has physical access to the device. Alternatively, this file is available id device repositories on Github and other places. A simple search on Google for `android_device_oem_device`, where oem is the name of device manufacturer such as `samsung`, `sony`, `motorola`, `lge`..., and device is the code name / technical name of the device such as `mako` for `Google Nexus 4` and `m0` for `Samsung Galaxy S III`.
|
|
|
|
In addition a PIT file or a scatter file for the specific device can also be used for deducing the partition layout.
|
|
|
|
|
|
|
|
Example (Partition Layout file on a HTC Sensation XL):
|
|
|
|
```none
|
|
|
|
dev: size erasesize name
|
|
|
|
mmcblk0p1: 0001f4 000000 "unknown"
|
|
|
|
mmcblk0p2: 000040 000000 "unknown"
|
|
|
|
mmcblk0p3: 001194 000000 "unknown"
|
|
|
|
mmcblk0p4: 000001 000000 "unknown"
|
|
|
|
mmcblk0p5: 007530 000000 "unknown"
|
|
|
|
mmcblk0p6: 0030d4 000000 "unknown"
|
|
|
|
mmcblk0p7: 000800 000000 "unknown"
|
|
|
|
mmcblk0p8: 000c00 000000 "unknown"
|
|
|
|
mmcblk0p9: 000800 000000 "unknown"
|
|
|
|
mmcblk0p10: 000400 000000 "unknown"
|
|
|
|
mmcblk0p11: 000400 000000 "unknown"
|
|
|
|
mmcblk0p12: 00222f 000000 "unknown"
|
|
|
|
mmcblk0p13: 000c00 000000 "unknown"
|
|
|
|
mmcblk0p14: 000c00 000000 "unknown"
|
|
|
|
mmcblk0p15: 000400 000000 "unknown"
|
|
|
|
mmcblk0p16: 0022fd 000000 "unknown"
|
|
|
|
mmcblk0p17: 000100 000000 "unknown"
|
|
|
|
mmcblk0p18: 000400 000000 "unknown"
|
|
|
|
mmcblk0p19: 000800 000000 "unknown"
|
|
|
|
mmcblk0p20: 000500 000000 "unknown"
|
|
|
|
mmcblk0p21: 0021fd 000000 "recovery"
|
|
|
|
mmcblk0p22: 001000 000000 "boot"
|
|
|
|
mmcblk0p23: 000100 000000 "unknown"
|
|
|
|
mmcblk0p24: 007bff 000000 "unknown"
|
|
|
|
mmcblk0p25: 0fffff 000000 "unknown"
|
|
|
|
mmcblk0p26: 000c00 000000 "unknown"
|
|
|
|
mmcblk0p27: 000c00 000000 "unknown"
|
|
|
|
mmcblk0p28: 0067fe 000000 "misc"
|
|
|
|
mmcblk0p29: 407fff 000000 "userdata"
|
|
|
|
mmcblk0p30: 08ffff 000000 "cache"
|
|
|
|
mmcblk0p31: 007eff 000000 "unknown"
|
|
|
|
mmcblk0p32: 000103 000000 "unknown"
|
|
|
|
mmcblk0p33: 8e4ffc 000000 "emmc"
|
|
|
|
```
|
|
|
|
|
|
|
|
<br /><br />
|
|
|
|
|
|
|
|
### MTK Based Devices
|
|
|
|
On devices based on MTK (MediaTek) chips, a file at `/proc/dumchar_info` is populated with the partition layout, by the linux kernel. This file, however is not similar to `/proc/mtd`, `/proc/emmc` and partition layout files used by Online Nandroid. Since MTK devices use the uboot mechanism, partitions including boor and recovery, are not revealed as separate partitions, but rather accessed sequencially by size and start parameters. The dumchar_info file has this size and start parameters specified in it. This file has some other major differences in partition naming such as the boot partition is named `bootimg` instead of `boot`, data partition is named `usrdata` instead of `userdata` system partition is named `android` instead of `system` and internal sd card is named `fat` instead `emmc`.
|
|
|
|
Online Nandroid (since v8.0) has built-in support for MTK based devices, thus does not require separate partition layout files on MTK based devices.
|
|
|
|
|
|
|
|
Example (`/proc/dumchar_info` on a Star N9770 Dual Core - MT6577):
|
|
|
|
```none
|
|
|
|
Part_Name Size StartAddr Type MapTo
|
|
|
|
preloader 0x0000000000040000 0x0000000000000000 2 /dev/misc-sd
|
|
|
|
dsp_bl 0x00000000005c0000 0x0000000000040000 2 /dev/misc-sd
|
|
|
|
mbr 0x0000000000004000 0x0000000000000000 2 /dev/block/mmcblk0
|
|
|
|
ebr1 0x0000000000004000 0x0000000000004000 2 /dev/block/mmcblk0p1
|
|
|
|
pmt 0x0000000000400000 0x0000000000008000 2 /dev/block/mmcblk0
|
|
|
|
nvram 0x0000000000500000 0x0000000000408000 2 /dev/block/mmcblk0
|
|
|
|
seccfg 0x0000000000020000 0x0000000000908000 2 /dev/block/mmcblk0
|
|
|
|
uboot 0x0000000000060000 0x0000000000928000 2 /dev/block/mmcblk0
|
|
|
|
bootimg 0x0000000000600000 0x0000000000988000 2 /dev/block/mmcblk0
|
|
|
|
recovery 0x0000000000600000 0x0000000000f88000 2 /dev/block/mmcblk0
|
|
|
|
sec_ro 0x0000000000600000 0x0000000001588000 2 /dev/block/mmcblk0p2
|
|
|
|
misc 0x0000000000060000 0x0000000001b88000 2 /dev/block/mmcblk0
|
|
|
|
logo 0x0000000000300000 0x0000000001be8000 2 /dev/block/mmcblk0
|
|
|
|
expdb 0x0000000000200000 0x0000000001ee8000 2 /dev/block/mmcblk0
|
|
|
|
android 0x0000000020100000 0x00000000020e8000 2 /dev/block/mmcblk0p3
|
|
|
|
cache 0x0000000020100000 0x00000000221e8000 2 /dev/block/mmcblk0p4
|
|
|
|
usrdata 0x0000000020100000 0x00000000422e8000 2 /dev/block/mmcblk0p5
|
|
|
|
fat 0x00000000854f8000 0x00000000623e8000 2 /dev/block/mmcblk0p6
|
|
|
|
bmtpool 0x0000000001500000 0x00000000ff9f00a8 2 /dev/block/mmcblk0
|
|
|
|
Part_Name:Partition name you should open;
|
|
|
|
Size:size of partition
|
|
|
|
StartAddr:Start Address of partition;
|
|
|
|
Type:Type of partition(MTD=1,EMMC=2)
|
|
|
|
MapTo:actual device you operate
|
|
|
|
```
|
|
|
|
|
|
|
|
<br /><br />
|
|
|
|
|
|
|
|
### Allwinner Based Devices |
