Analysis of Nokia 5320 XpressMusic Firmware Image: Deconstructing the RPKG-based ROM Structure
| Phone Model | Nokia 5320 XpressMusic | |------------------|------------------------| | Platform | BB5 (Baseband 5) | | OS | Symbian OS 9.3 (S60v3) | | Product Code | RM-409 | | Firmware files | .rpk , .rofs , .uda | | Typical size | ~64–128 MB (core + rofs) | nokia 5320 image -rom rpkg-
Given the fragment image -rom rpkg- , we hypothesize that rpkg is a concatenation of: The findings aid in understanding custom firmware creation,
The Nokia 5320 XpressMusic (RM-409) represents a generation of Symbian OS v9.3-based smartphones where firmware was distributed as monolithic image files. This paper examines the internal layout of the 5320_rm409_*.rpk image (assumed variant of Nokia’s .rpk or packaged core ROM). We propose a structural model for the image’s partition table, file system containers (ROFS), and certificate metadata. The findings aid in understanding custom firmware creation, dead USB recovery, and security bypass analysis. 1. Introduction The Nokia 5320 featured ARM11-based hardware with NAND flash divided into multiple partitions: OS kernel (in Core), ROFS (read-only file system), and user data (UDA). Official firmware came as .exe packages containing .rpk or .co files. The term “RPKG” is interpreted here as a package akin to RAPIDO PKG — a container for compressed image segments. Official firmware came as