Add ELF handling (WIP)

1 files changed, 62 insertions, 2 deletions

diff --git a/elf.h b/elf.h
index 0b47fb6..9d1ba69 100644
--- a/elf.h
+++ b/elf.h
@@ -1,22 +1,82 @@
 #pragma once
 
-#pragma pack(push, 1)
+#include <bit>
+#include <cstdint>
+#include <filesystem>
+#include <vector>
 
 namespace Elf {
 
 // ELF 64 bit only
 
+#pragma pack(push, 1)
 struct FileHeader
 {
+ enum {
+  EI_MAG0 = 0,
+  EI_MAG1,
+  EI_MAG2,
+  EI_MAG3,
+  EI_CLASS,
+  EI_DATA,
+  EI_VERSION,
+  EI_OSABI,
+  EI_ABIVERSION,
+  EI_PAD
+ };
+ uint8_t e_ident[16]{
+  0x7F, 0x45, 0x4C, 0x46, // .ELF
+  2, // 64 bit
+  1, // little endian
+  1, // Version: default == 1
+  3, // Linux
+  0, // EI_ABIVERSION
+  0,0,0,0,0,0,0 // pad
+ };
+ uint16_t e_type{0x02}; // ET_EXEC
+ uint16_t e_machine{0x3E}; // AMD64
+ uint32_t e_version{1};
+ uint64_t e_entry{0x0000000000401000};
+ uint64_t e_phoff{0x40};
+ uint64_t e_shoff{}; // section header table offset
+ uint32_t e_flags{0x00000112}; // EXEC_P, HAS_SYMS, D_PAGED
+ uint16_t e_ehsize{0x40}; // size of this header
+ uint16_t e_phentsize{0x38}; // size of program header
+ uint16_t e_phnum{1}; // 1 program header
+ uint16_t e_shentsize{0x40}; // size of section header
+ uint16_t e_shnum{2}; // number of section headers
+ uint16_t e_shstrndx{1}; // 1st section header contains section names
 };
 
+// Segment
 struct ProgramHeader
 {
+ uint32_t p_type{1}; // Loadable segment
+ uint32_t p_flags{5}; // X=1 | W=2 | R=4
+ uint64_t p_offset{0x0}; // offset in file
+ uint64_t p_vaddr{0x401000}; // virtual address
+ uint64_t p_paddr{0x401000}; // physical address, not really relevant
+ uint64_t p_filesz{}; // size of segment in file, e.g. size of code
+ uint64_t p_memsz{}; // size of segment in memory
+ uint64_t p_align{0}; // alignment
 };
 
 struct SectionHeader
 {
+ uint32_t sh_name{}; // offset of name in .shstrtab
+ uint32_t sh_type{1}; // program data
+ uint64_t sh_flags{6}; // ALLOC, EXE
+ uint64_t sh_addr{0x401000}; // virtual address
+ uint64_t sh_offset{0x1000};
+ uint64_t sh_size{}; // section size
+ uint32_t sh_link{};
+ uint32_t sh_info{};
+ uint64_t sh_addralign{};
+ uint64_t sh_entsize{};
 };
+#pragma pack(pop)
 
+void Write(const std::filesystem::path& path, const std::vector<uint8_t>&);
+std::vector<uint8_t> Read(const std::filesystem::path& path);
 }
-#pragma pack(pop)
+