Function elf_writer_serialize

util/cbfstool/elfheaders.c:1137–1247

* Serialize the ELF file to the output buffer. Return < 0 on error, * 0 on success. */

 * 0 on success.
 */
int elf_writer_serialize(struct elf_writer *ew, struct buffer *out)
{
	Elf64_Half i;
	Elf64_Xword metadata_size;
	Elf64_Xword program_size;
	Elf64_Off shstroffset;
	size_t shstrlen;
	struct buffer metadata;
	struct buffer phdrs;
	struct buffer data;
	struct buffer *strtab;

	INFO("Writing %zu sections.\n", ew->num_secs);

	/* Perform any necessary work for special sections. */
	fixup_symbol_table(ew);
	fixup_relocations(ew);

	/* Determine size of sections to be written. */
	program_size = 0;
	/* Start with 1 byte for first byte of section header string table. */
	shstrlen = 1;
	for (i = 0; i < ew->num_secs; i++) {
		struct elf_writer_section *sec = &ew->sections[i];

		if (sec->shdr.sh_flags & SHF_ALLOC) {
			if (!section_consecutive(ew, i))
				ew->ehdr.e_phnum++;
		}

		program_size += buffer_size(&sec->content);

		/* Keep track of the length sections' names. */
		if (sec->name != NULL) {
			sec->shdr.sh_name = shstrlen;
			shstrlen += strlen(sec->name) + 1;
		}
	}
	ew->ehdr.e_shnum = ew->num_secs;
	metadata_size = 0;
	metadata_size += ew->ehdr.e_ehsize;
	metadata_size += (Elf64_Xword)ew->ehdr.e_shnum * ew->ehdr.e_shentsize;
	metadata_size += (Elf64_Xword)ew->ehdr.e_phnum * ew->ehdr.e_phentsize;
	shstroffset = metadata_size;
	/* Align up section header string size and metadata size to 4KiB */
	metadata_size = ALIGN_UP(metadata_size + shstrlen, 4096);

	if (buffer_create(out, metadata_size + program_size, "elfout")) {
		ERROR("Could not create output buffer for ELF.\n");
		return -1;
	}

	INFO("Created %zu output buffer for ELF file.\n", buffer_size(out));

	/*
	 * Write out ELF header. Section headers come right after ELF header
	 * followed by the program headers. Buffers need to be created first
	 * to do the writing.