# Relocation processing (ivss)

**Relocation processing** turns symbol-based references into concrete runtime values. ivss's linker adjusts records while merging objects; the emulator's loader applies their patches. It computes the referenced value as follows:

```c
Elf_Addr value = symb->st_value;
value += rela->r_addend;
if (symb->st_shndx != SHN_ABS) {
    Elf_PushSection(elf);
    Elf_Shdr *sym_shdr = Elf_SetSection(elf, symb->st_shndx);
    value += sym_shdr->sh_addr;
    Elf_PopSection(elf);
}
```

A section-defined symbol needs its section's base address added. An absolute symbol already has its final value, so that addition is skipped. The relocation addend applies in both cases.

For `R_SS_32`, the loader writes the result as a word at the relocation's target offset. Expanded-load relocations instead distribute it through the bytes of an instruction sequence.

This explains why linked serialized bytes can still contain placeholders. The effective memory image differs after loading. A successful check should examine the program's loaded behavior or memory, rather than assume that every reference has already been patched in the linker's output file.

Source: [emulator.c](https://github.com/yanevskiv/ivss/blob/main/src/emulator.c).