[Elftoolchain-developers] Insert (retrieve) a section into (from) an elf

[陳韋任 <ch...@cs...>]

Hi, all:

  I plan to add some data into an elf file, then retrieve those data
back when running the elf file. I would like to use libelf to get the
job done.

  For adding data into an elf file, I found 'objcopy --add-section
sectionname=filename theElf' can do the same thing without using libelf.
Am I right? Will 'objcopy' update all related entries? Or I have to use
libelf to do it?

  Then for retrieving data within a particular section, I tried to use
those API mentioned in the tutorial "libelf by Example" written by Joseph.
I found the procedure was quite different from my original thought.

  At first, I tended to iterate though the section header table. With
the "sh_name" member in the section header table entry and shstrndx,
I could find the section I want by comparing the section name.

  However, what I done now was iterating though all sections, NOT section
header table, then got associated section table entry and compared the
section name. It's pretty much like the program 4 (listing all section names)
in the tutorial "libelf by Example".

  I don't know if it is the only way to get data in a particular
section. Any suggestion will be appreciated.

Regards,
chenwj

-- 
Wei-Jen Chen (陳韋任)
Programming Language and System Laboratory (EC131)
Department of Computer Science, National Chiao Tung University