• Journal of Korea Multimedia Society
• /
• v.13 no.2
• /
• pp.161-170
• /
• 2010

ELF, an abbreviation for Executable and Linkable Format, is the basic file format for shared libraries and executable files used in the Linux system, whereas 'Linker' copies the symbol information of static shared libraries into the symbol table in the target file generated by way of static linking. At this time, the symbol table keeps various pieces of debugging-related information including function names provided by the shared libraries, and it can be deleted to avoid debugging for security reasons by utilizing the fact that it does not directly affect the program execution. This paper proposes a method for restoring the symbol information of static shared libraries from the ELF object file in which the symbol table is deleted, and confirms that the symbol information is restored by conducting practical experiments.

• Journal of KIISE:Computing Practices and Letters
• /
• v.11 no.1
• /
• pp.15-25
• /
• 2005

Embedded systems have a set of tasks to execute. These tasks can be implemented either on application specific hardware or as software running on a specific processor. The design of an embedded system involves the selection of hardware software resources, Partition of tasks into hardware and software, and performance evaluation. An accurate estimation of execution time for extreme cases (best and worst case) is important for hardware/software codesign. A tighter estimation of the execution time bound nay allow the use of a slower processor to execute the code and may help lower the system cost. In this paper, we consider an ARM-based embedded system and developed a tool to estimate the tight boundary of execution time of a task with loop bounds and any additional program path information. The tool we developed is based on an exiting timing analysis tool named 'Cinderella' which currently supports i960 and m68k architectures. We add a module to handle ARM ELF object file, which extracts control flow and debugging information, and a module to handle ARM instruction set so that the new tool can support ARM processor. We validate the tool by comparing the estimated bound of execution time with the run-time execution time measured by ARMulator for a selected bechmark programs.