Function from_elf

icicle-cortexm/src/genconfig.rs:102–295

Attempts to generate a Fuzzware compatible config file from an ELF binary. Note: Unlike the original Fuzzware implementation, we rely entirely on the information included in the ELF file. We never attempt to manually identify sections.

(path: &Path)

/// Note: Unlike the original Fuzzware implementation, we rely entirely on the information included
/// in the ELF file. We never attempt to manually identify sections.
pub fn from_elf(path: &Path) -> anyhow::Result<FirmwareConfig> {
    let data = std::fs::read(path)?;

    // TODO: we parse the binary as a generic file, just to find names of sections we could avoid
    // this by directly getting names specialized reader.
    let obj_file = object::File::parse(data.as_slice())?;

    let elf = object::elf::FileHeader32::<Endianness>::parse(data.as_slice())?;
    let endian = elf.endian()?;

    let file_name = path
        .file_name()
        .and_then(|x| x.to_str())
        .ok_or_else(|| anyhow::format_err!("unable to extract file name"))?;

    // Start with initial cortexm memory map.
    let mut memory = cortexm_memory_map();
    let ram_range = memory.get("ram").map(|x| x.base_addr..x.base_addr + x.size);

    for section in obj_file.sections() {
        tracing::info!(
            "section \"{}\" address={:#x} size={:#x}",
            section.name()?,
            section.address(),
            section.size()
        );
    }

    // Determine what needs to be loaded by inspecting program headers
    let program_headers = elf.program_headers(endian, data.as_slice())?;

    for (idx, segment) in program_headers.into_iter().enumerate() {
        if segment.p_type(endian) != object::elf::PT_LOAD {
            continue;
        }

        let p_flags = segment.p_flags(endian);
        let base_addr = segment.p_paddr(endian) as u64;
        let vaddr = segment.p_vaddr(endian) as u64;
        let in_memory_size = segment.p_memsz(endian) as u64;

        // Find a name to use for the segment by looking at section headers (note: segments don't
        // have a name for ELF files).
        let range = vaddr..vaddr + in_memory_size.max(1);
        let mut name =
            find_section_name(&obj_file, range).unwrap_or_else(|| format!("memory_{base_addr:#x}"));

        if let Some(suffix) = name.strip_prefix(".") {
            name = suffix.into();
        }

        tracing::info!(
            "PL_LOAD base_addr={base_addr:#x} (vaddr={vaddr:#x}) size={in_memory_size:#x} (name={name})"
        );

        if in_memory_size == 0 {
            tracing::debug!("ignoring zero sized segment: Idx={idx}: {base_addr:#x} ({name})");
            continue;