You can edit the system and boot partitions in Windows with RKCooking Utility
I already added these instructions to the topic.Modify a ROM with RKCooking utility
1.- Copy Update.img or img file to c:\rkcooking\Rombase
2.- Run RKCooking utility and Press: 1 to create a ROM from a modified ROM.
The utility shows all images in folder.
Write the name of image file without .img filename extension
3.- Press in the submenu: 1) Unpack the image previously assigned.
* Unpacking Image...
Check file... OK
------- UNPACK ------
HWDEF 0x00000800 0x0000032D
package-file 0x00001000 0x00000216
RK28xxLoader(L).bin 0x00001800 0x00020314
parameter 0x00022000 0x00000209
Image/misc.img 0x00022800 0x0000C000
Image/kernel.img 0x0002E800 0x0054759D
Image/boot.img 0x00576000 0x0002B004
Image/recovery.img 0x005A1800 0x0024F004
Image/system.img 0x007F1000 0x07667004
SELF 0x00000000 0x07E59804
Skip SELF file.
update-script 0x07E58800 0x000004B5
recover-script 0x07E59000 0x0000010A
* Press ENTER to continue.
4.- Now you have the following files in c:\rkcooking\temp:
In folder c:\rkcooking\temp\image you have the partitions:
- boot.img Boot: parttion with scripts and files to boot
- kernel.img: The linux kernel
- misc.img: miscellaneous partition
- recovery.img: Recovery partition with scripts to recover and flash update.img etc.
- system.img: The main Android partition, where aplics are...
5.- Press 2 to Change(s) image(s) with NewTuxFlash.exe
Invoke NewTuxFlash and open c:\rkcooking\temp\image\system.img or c:\rkcooking\temp\image\boot.img
The 2 partitions NewTuxFlash can open are system.img or boot.img.
You can remove applicationss in /system/app folder or paste new apps too.
If you press right button on file you can edit file permissions.
To copy standard apps to /system/app, just select in windows explorer and copy it, and paste it (or them) in /system/app.
The filename permissions for standard apps are very important and should be the same it have in /data/app. In My tablet I put:
User: 1000, Group:1000 (it will be trunked to 8 bits and will be 232), User:RW, Group R, Other:R
You can edit script OR text files as buid.prop and save it modified.
6.- When you save a modified partition add "_new" to the end of name, example: system.img save it as system_new.img and boot.img save it as boot_new.img.
7 When you have modified a system or boot partition, YOU MUST SIGN THE IMAGE FILE.
Press 3 to Sign image(s) that have been saved with NewTuxFlash.exe
8.- When you have signed the modified partitions, you can repack the rom file:
Press 4 Pack images in \temp\ folder, and write the filename you want but do not use spaces. don't put .img filename extension.
The rom image file you have cooked is in c:\RkCooking\Cookedrom
9.- Press 5 to Flash the ROM. You can Upload any rom to the tablet with this menu option.
Invokes RK2818BatchUpgrade 1.23. You must select one image file, don't use Boot and don't tick Demo, and press Upgrade.
I ever make a simple test to be sure the rom is OK before to flashing, I move the new packed rom image file from cookedrom to rombase folder,
and rename the c:\rkcooking\temp folder to other name esxample:temp1, and select 7 to go to main menu and then select 1 to unpack rom...
If the rom is unpacked OK, it can be flashed. If you have any error... review the steps...
10.- To root the tablet you must copy the following files in system partition:
SuperUser.apk to system/app and put the following file permissions: User: 0, Group:0, User:RWX, Group R, Other:R
su to /bin and put the following file permissions: User: 0, Group:0, User:RWX, Group:RWX, Other:RWX
busybox and put the following file permissions: User: 1000, Group:1000, User:RWX, Group:RWX, Other:RWX
The other files in /bin folder should have the following file permissions: User: 1000(System), Group:1000(System), User:RWX, Group:RWX, Other:RWX