Cook Symbian Custom Firmware: Firmware Files

In this post i will give an idea about different files we downloaded. What are they and where they will go when we flash it to our devices. We have already downloaded some 8-10 files. We don’t need all the files, some are compressed file system images and rest are configuration files and signatures etc. We need only the file system files which contains the files for modding. In this case i will using nokia 5230 (RM-588) firmware version 21.6.5  product code 0599208.

These are the important files needed

  • MCU Core : RM-588_21.6.005_prd.core.C00
  • PPM rofs2: RM-588_21.6.005_prd.rofs2.V22
  • PPM rof3 : RM-588_21.6.005_C01_prd.rofs3.fpsx
  • Content : RM-588_21.6.005_001_000_U001.uda.fpsx
  • MemCardContent :5230_SW_MC012_India_2G_2.0.fpsx


Some time of you have downloaded from navifirm there is a chance of finding file name little different, like some strange string in beginning of file name or “-” may be replaced by “_”. do the necessary changes so that the file names are shown above.

As i said these files are images of compressed file system. I will briefly explain a little about each file

MCU Core File

This is the core of the OS file system. It will be having the all OS related files of the particular version of firmware. It will be same for all the product product variant. This is the first file system which is flashed on to the device ROM. Usually we wont modify this MCU core file. we will flash as it is to the device.

PPM rofs2

This bundle usually contain the different language files, font files , some modes etc. This will be written to Device rom after MCU file so we can overwrite an file that is inside mcu core by placing a modified copy in RFOS2 archive. We will be using this for most of our mods and tweeks for custom firmware. maximum possible size of rofs2 file is 33 MB

PPM rofs3

This archive will be containing custom themes,apps and other info etc we edit this archive also to bring our custom mods. This will be flashed after rofs3 , so it has the power to overwrite any file on core or rof2 files.

All these core, rofs2,rofs3 will be flashed to the rom drive , also displayed as Z drive in some symbian file managers. once this is flashed to the phones we wont be able to edit other than re-flashing.

UDA content

This is file system which is flashed on to the Phone memory( the c drive). We may change some files if we needed to bring custom modes in phone memory. But when we do a hard rest the entire phone memory is wiped to default.