From 78f0df1cf849af8b0ade40a8ebcffd7fb53635cb Mon Sep 17 00:00:00 2001 From: Felix Morgner Date: Thu, 30 Oct 2025 15:59:48 +0100 Subject: libs: begin ELF support implementation --- libs/elf/include/elf/format.hpp | 15 +++++++++++++++ libs/elf/include/elf/section_header.hpp | 23 +++++++++++++++++++++++ 2 files changed, 38 insertions(+) create mode 100644 libs/elf/include/elf/format.hpp create mode 100644 libs/elf/include/elf/section_header.hpp (limited to 'libs/elf/include') diff --git a/libs/elf/include/elf/format.hpp b/libs/elf/include/elf/format.hpp new file mode 100644 index 0000000..b3220f5 --- /dev/null +++ b/libs/elf/include/elf/format.hpp @@ -0,0 +1,15 @@ +#ifndef ELF_FORMAT_HPP +#define ELF_FORMAT_HPP + +namespace elf +{ + + enum struct format + { + elf32, + elf64, + }; + +} // namespace elf + +#endif \ No newline at end of file diff --git a/libs/elf/include/elf/section_header.hpp b/libs/elf/include/elf/section_header.hpp new file mode 100644 index 0000000..0ff5e4b --- /dev/null +++ b/libs/elf/include/elf/section_header.hpp @@ -0,0 +1,23 @@ +#ifndef ELF_SECTION_HEADER_HPP +#define ELF_SECTION_HEADER_HPP + +#include "format.hpp" + +#include + +namespace elf +{ + + enum struct section_header_type : std::uint32_t + { + }; + + template + struct section_header + { + std::uint32_t name_offset; + section_header_type type; + }; +} // namespace elf + +#endif \ No newline at end of file -- cgit v1.2.3 From 31c5f011b2c7b4cc65d4017d92c2fe0bdf7f4ba6 Mon Sep 17 00:00:00 2001 From: Felix Morgner Date: Fri, 31 Oct 2025 11:16:12 +0100 Subject: libs/elf: implement section headers --- libs/elf/include/elf/section_header.hpp | 66 ++++++++++++++++++++++++++++++--- 1 file changed, 61 insertions(+), 5 deletions(-) (limited to 'libs/elf/include') diff --git a/libs/elf/include/elf/section_header.hpp b/libs/elf/include/elf/section_header.hpp index 0ff5e4b..73e2e7b 100644 --- a/libs/elf/include/elf/section_header.hpp +++ b/libs/elf/include/elf/section_header.hpp @@ -4,20 +4,76 @@ #include "format.hpp" #include +#include +#include namespace elf { - enum struct section_header_type : std::uint32_t - { - }; + template + constexpr auto inline section_header_size = std::numeric_limits::max(); + + template<> + constexpr auto inline section_header_size = 40uz; + + template<> + constexpr auto inline section_header_size = 64uz; template struct section_header { - std::uint32_t name_offset; - section_header_type type; + using format_uint = std::conditional_t; + + enum struct header_type : std::uint32_t + { + null = 0, ///< Is inactive + program_data = 1, ///< Contains program data + symbol_table = 2, ///< Contains a symbol table + string_table = 3, ///< Contains a string table + relocation_entries_with_addends = 4, ///< Contains relocation information with addends + hash_table = 5, ///< Contains a symbol hash table + dynamic_linking_entries = 6, ///< Contains dynamic linking information + notes = 7, ///< Contains additional notes about the object file + no_content = 8, ///< Contains no data + relocation_entries_without_addends = 9, ///< Contains relocation information without addends + reserved = 10, ///< Reserved for future use + dynamic_linker_symbol_table = 11, ///< Contains the dynamic linker symbol table + init_array = 14, ///< Contains an array of constructor pointers + fini_array = 15, ///< Contains an array of destructor pointers + preinit_array = 16, ///< Contains an array of pre-constructor pointers + group_table = 17, ///< Defines a section group + extended_section_header_indices = 18, ///< Contains extended section header indices + }; + + enum struct header_flags : format_uint + { + writeable = 0x1, ///< Contains writable data + allocated = 0x2, ///< Occupies memory during execution + executable = 0x4, ///< Contains executable instructions + mergeable = 0x10, ///< Contained data may be merged for deduplication + strings = 0x20, ///< Contains null-terminated strings + info_link = 0x40, ///< Contains the section header index of linked section + link_order = 0x80, ///< Must respect linking location relative to linked section + os_specific = 0x100, ///< Must be handled in an OS specific way + group_member = 0x200, ///< Is a member of a section group + thread_local_storage = 0x400, ///< Contains thread local storage data + compressed = 0x800, ///< Is compressed + }; + + std::uint32_t name_offset; ///< Offset into the section header string table, defining the section name + header_type type; ///< Type of this section + header_flags flags; ///< Flags of this section + format_uint virtual_load_address; ///< Virtual address where this section is loaded + format_uint file_offset; ///< Offset of the start of this section's data in the file + format_uint size; ///< Size of this section in memory + std::uint32_t linked_section; ///< Index of a section this section is linked to + std::uint32_t extra_info; ///< Additional information for this section (type and flag dependent) + format_uint alignment; ///< Alignment requirement of this section in memory + format_uint entry_size; ///< Size of the entries inside this section (if any) }; + + static_assert(sizeof(section_header) == section_header_size); + static_assert(sizeof(section_header) == section_header_size); } // namespace elf #endif \ No newline at end of file -- cgit v1.2.3 From 53402f496ee07351923945f523565f9aa618005a Mon Sep 17 00:00:00 2001 From: Felix Morgner Date: Fri, 5 Dec 2025 15:13:57 +0100 Subject: elf: add basic section_header flag tests --- libs/elf/include/elf/section_header.hpp | 20 ++++++++++++++++++++ 1 file changed, 20 insertions(+) (limited to 'libs/elf/include') diff --git a/libs/elf/include/elf/section_header.hpp b/libs/elf/include/elf/section_header.hpp index 73e2e7b..3afe334 100644 --- a/libs/elf/include/elf/section_header.hpp +++ b/libs/elf/include/elf/section_header.hpp @@ -6,6 +6,7 @@ #include #include #include +#include namespace elf { @@ -60,6 +61,24 @@ namespace elf compressed = 0x800, ///< Is compressed }; + //! Check if the section is allocated + [[nodiscard]] constexpr auto allocated() const noexcept -> bool + { + return std::to_underlying(flags) & std::to_underlying(header_flags::allocated); + } + + //! Check if the section is executable + [[nodiscard]] constexpr auto executable() const noexcept -> bool + { + return std::to_underlying(flags) & std::to_underlying(header_flags::executable); + } + + //! Check if the section is writeable + [[nodiscard]] constexpr auto writable() const noexcept -> bool + { + return std::to_underlying(flags) & std::to_underlying(header_flags::writeable); + } + std::uint32_t name_offset; ///< Offset into the section header string table, defining the section name header_type type; ///< Type of this section header_flags flags; ///< Flags of this section @@ -74,6 +93,7 @@ namespace elf static_assert(sizeof(section_header) == section_header_size); static_assert(sizeof(section_header) == section_header_size); + } // namespace elf #endif \ No newline at end of file -- cgit v1.2.3