⚠️Repository Archived

This repository is no longer actively maintained.
Issues and pull requests are not being monitored.

The code remains available for reference, but no work on it is currently planned.

elfloader

A library to load and relocate ELF files in memory. This library depends only on libcore so it can be used in kernel level code, for example to load user-space programs.

How-to use

Clients will have to implement the ElfLoader trait:

use elfloader::*;use log::info;/// A simple ExampleLoader, that implements ElfLoader/// but does nothing but loggingstructExampleLoader{vbase:u64,}implElfLoaderforExampleLoader{fnallocate(&mutself,load_headers:LoadableHeaders) -> Result<(),ElfLoaderErr>{for header in load_headers {info!("allocate base = {:#x} size = {:#x} flags = {}",
header.virtual_addr(),
header.mem_size(),
header.flags());}Ok(())}fnrelocate(&mutself,entry:RelocationEntry) -> Result<(),ElfLoaderErr>{useRelocationType::x86_64;usecrate::arch::x86_64::RelocationTypes::*;let addr:*mutu64 = (self.vbase + entry.offset)as*mutu64;match entry.rtype{
x86_64(R_AMD64_RELATIVE) => {// This type requires addend to be presentlet addend = entry
.addend.ok_or(ElfLoaderErr::UnsupportedRelocationEntry)?;// This is a relative relocation, add the offset (where we put our// binary in the vspace) to the addend and we're done.info!("R_RELATIVE *{:p} = {:#x}",
addr,self.vbase + addend
);Ok(())}
_ => Ok((/* not implemented */)),}}fnload(&mutself,flags:Flags,base:VAddr,region:&[u8]) -> Result<(),ElfLoaderErr>{let start = self.vbase + base;let end = self.vbase + base + region.len()asu64;info!("load region into = {:#x} -- {:#x}", start, end);Ok(())}fntls(&mutself,tdata_start:VAddr,_tdata_length:u64,total_size:u64,_align:u64) -> Result<(),ElfLoaderErr>{let tls_end = tdata_start + total_size;info!("Initial TLS region is at = {:#x} -- {:#x}", tdata_start, tls_end);Ok(())}}// Then, with ElfBinary, a ELF file is loaded using `load`:fnmain(){use std::fs;let binary_blob = fs::read("test/test.x86_64").expect("Can't read binary");let binary = ElfBinary::new(binary_blob.as_slice()).expect("Got proper ELF file");letmut loader = ExampleLoader{vbase:0x1000_0000};
binary.load(&mut loader).expect("Can't load the binary?");}