In our 6th semester we developed miASMa - a 2 pass Macro Assembler for an x86 machine. miASMa generates Relocatable Object Files that conforming to the ELF Format.

1. Hareesh Nagarajan Pramod Kumar Both from 7 th Semester CSE at RV College of Engineering A hands-on introduction to the ELF Object file format

4. The ELF Header

5. Sections in ELF

6. Special Sections Various sections in ELF are predefined and hold program and control Information.

7. The Quick look at the String table This is how most string tables in the ELF look like.

8. The Symbol Table (I'm bored, I thought this was talk made use of a hands-on approach :( )

9. The RelocationTable (We are almost there !)

13. bool AddRelocationEntry(Elf32_Addr roffset, unsigned char rsym, unsigned char rtype, int SectionIndex); obj.AddRelocationEntry(11, obj.ReturnSymbolIndex("myvariable"), R_386_RELATIVE, obj.GetSectionIndexOfType(SHT_REL, ".rel.text")); obj.PrepareFile(); obj.WriteFile("hello.o"); //Yippie! The OBJECT FILE is created Finally… Prototype

14. Memory map of hello.o $ g++ sample.cpp libmiasmaelf.o $./a.out ---> hello.o written!