Lenovo Tab 2 Partition Layout

Question

I own a Lenovo Tab 2 A7-20f.

When I try cat /proc/emmc:

partno:
 start_sect
nr_sects  partition_name

emmc_p1: 00000400 00000002 "ebr1"

emmc_p2: 00004800 00005000 "protect_f"

emmc_p3: 00009800 00005000 "protect_s"

emmc_p4: 0001ec00 00003000 "sec_ro"

emmc_p5: 0002e800 00300000 "android"

emmc_p6: 0032e800 0003f000 "cache"

emmc_p7: 0036d800 00b18000 "usrdata"

And when I use cat /proc/partitions:

major minor  #blocks  name




7

  0

 9570 loop0

 253

  0
  524288 zram0

 179

  0
 7613440 mmcblk0

 179

  1

 1 mmcblk0p1

 179

  2

10240 mmcblk0p2

 179

  3

10240 mmcblk0p3

 179

  4

 6144 mmcblk0p4

 179

  5
 1572864 mmcblk0p5

 179

  6
  129024 mmcblk0p6

 179

  7
 5816320 mmcblk0p7

 179

 64

 4096 mmcblk0boot1

 179

 32

 4096 mmcblk0boot0

I don't think this is the typical Android Partition Layout. Any Idea which one is the Recovery and the Boot partition?
Or how to find it out?

Update:

When I lookup /proc/dumchar_info I get

Part_Name  Size
 StartAddr
Type
 MapTo
Region

preloader
 0x0000000000040000
0x0000000000000000
2
/dev/misc-sd
  BOOT_1

mbr

 0x0000000000080000
0x0000000000000000
2
/dev/block/mmcblk0
  USER

ebr1

0x0000000000080000
0x0000000000080000
2
/dev/block/mmcblk0p1
USER

pro_info
  0x0000000000300000
0x0000000000100000
2
/dev/block/mmcblk0
  USER

nvram

  0x0000000000500000
0x0000000000400000
2
/dev/block/mmcblk0
  USER

protect_f
 0x0000000000a00000
0x0000000000900000
2
/dev/block/mmcblk0p2
USER

protect_s
 0x0000000000a00000
0x0000000001300000
2
/dev/block/mmcblk0p3
USER

seccfg

 0x0000000000020000
0x0000000001d00000
2
/dev/block/mmcblk0
  USER

uboot

  0x0000000000060000
0x0000000001d20000
2
/dev/block/mmcblk0
  USER

bootimg

0x0000000001000000
0x0000000001d80000
2
/dev/block/mmcblk0
  USER

recovery
  0x0000000001000000
0x0000000002d80000
2
/dev/block/mmcblk0
  USER

sec_ro

 0x0000000000600000
0x0000000003d80000
2
/dev/block/mmcblk0p4
USER

misc

0x0000000000080000
0x0000000004380000
2
/dev/block/mmcblk0
  USER

logo

0x0000000000300000
0x0000000004400000
2
/dev/block/mmcblk0
  USER

expdb

  0x0000000000a00000
0x0000000004700000
2
/dev/block/mmcblk0
  USER

tee1

0x0000000000500000
0x0000000005100000
2
/dev/block/mmcblk0
  USER

tee2

0x0000000000500000
0x0000000005600000
2
/dev/block/mmcblk0
  USER

kb

  0x0000000000100000
0x0000000005b00000
2
/dev/block/mmcblk0
  USER

dkb

 0x0000000000100000
0x0000000005c00000
2
/dev/block/mmcblk0
  USER

android

0x0000000060000000
0x0000000005d00000
2
/dev/block/mmcblk0p5
USER

cache

  0x0000000007e00000
0x0000000065d00000
2
/dev/block/mmcblk0p6
USER

usrdata

0x0000000163000000
0x000000006db00000
2
/dev/block/mmcblk0p7
USER

bmtpool

0x0000000001500000
0x00000000ffff00a8
2
/dev/block/mmcblk0
  USER

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

Now how can I found out which one is the system partition and why are Boot and Recovery one partition?

— Finn KrauÃŸ | Sources

Answer

Why are Boot and Recovery one partition?

This you can find answered in a Wiki entry at Github. Quoting the relevant part:

Since MTK devices use the uboot mechanism, partitions including boot and recovery, are not revealed as separate partitions, but rather accessed sequencially by size and start parameters.

You can see that reflected in your output of /proc/dumchar_info: size is the second column, start sector the third. Think of it like "disk images stored on a raw medium" (not an exact description, but easier to visualize).

Which one is the system partition?

My first guess (by the name) was sec_ro (as system is "ro", read only). But that's not exact enough. To find out, you'd need the sector size and the size of your /system partition, then you can do the maths: /proc/emmc gives you the "number of sectors" each partition occupies, in HEX. sec_ro accordingly occupies 0x3000 sectors, that would be 12288 in decimal. At a sector size of 512 bytes¹ that would be 6 MB â€“ too small :) A better guess probably is p5 named "android", which sums up to 1.5 GB â€“ that seems to be the correct size. cache is /cache and usrdata will be the /data partition.

^{1: according to Understanding MTKâ€™s MBR/EBR File Format}

— Izzy | Sources

Why are Boot and Recovery one partition?

Which one is the system partition?

Topics