tiny.tldr.formats.elf.layout.output

1const root = @import("../../../root.zig");2const elf = @import("../root.zig");34const model = root.model;5const OutputSection = elf.layout.OutputSection;6const output_section_count = elf.output_section.output_section_count;7const ehdr_size = elf.format.ehdr_size;8const phdr_size = elf.format.phdr_size;9const alignForward = elf.format.alignForward;10const alignForwardU64 = elf.format.alignForwardU64;11const reserveSize = elf.layout.reserveSize;1213pub fn countLive(output_sections: []const OutputSection) usize {14    var count: usize = 0;15    for (output_sections) |section| {16        if (section.logicalSize() != 0) count += 1;17    }18    return count;19}2021pub fn assign(22    output_sections: *[output_section_count]OutputSection,23    options: model.LinkOptions,24    program_header_count: usize,25) model.Error!void {26    var file_offset = ehdr_size + program_header_count * phdr_size;27    var address_cursor = options.image_base;28    var section_index: u16 = 1;29    var previous_alloc_was_tls = false;30    for (output_sections) |*section| {31        const logical_size = section.logicalSize();32        if (logical_size == 0) continue;33        file_offset = alignForward(file_offset, @intCast(@max(section.alignment, 1)));34        section.file_offset = @intCast(file_offset);35        section.address = if (section.kind.isAllocated())36            if (section.kind.isTls() and previous_alloc_was_tls)37                address_cursor38            else39                loadAddressForFileOffset(address_cursor, section.file_offset, options.page_size)40        else41            0;42        section.reserved_size = reserveSize(logical_size, section.alignment, options);43        section.section_index = section_index;44        section_index += 1;45        if (section.kind.isAllocated()) {46            address_cursor = section.address + section.reserved_size;47            previous_alloc_was_tls = section.kind.isTls();48        }49        file_offset += @intCast(section.fileLoadSize());50    }51}5253fn loadAddressForFileOffset(address_cursor: u64, file_offset: u64, page_size: u64) u64 {54    if (page_size <= 1) return address_cursor + file_offset;55    return alignForwardU64(address_cursor, page_size) + file_offset % page_size;56}

1pub const output = @import("output.zig");