bug.zig

// Flags to be set in the ’flags’ member of the multiboot info structure.
const InfoFlags = packed struct {
    // Is there basic lower/upper memory information?
    memory: bool,           // 0x00000001

    // Is there a boot device set?
    bootdev: bool,          // 0x00000002

    // Is the command-line defined?
    cmdline: bool,          // 0x00000004

    // Are there modules to do something with?
    mods: bool,             // 0x00000008

    // Is there a symbol table loaded? Mutually exclusive with elf_shdr.
    aout_syms: bool,        // 0x00000010

    // Is there an ELF section header table? Mutually exclusive with aout_syms.
    elf_shdr: bool,         // 0x00000020

    // Is there a full memory map?
    mem_map: bool,          // 0x00000040

    // Is there drive info?
    drive_info: bool,       // 0x00000080

    // Is there a config table?
    config_table: bool,     // 0x00000100

    // Is there a boot loader name?
    boot_loader_name: bool, // 0x00000200

    // Is there an APM table?
    apm_table: bool,        // 0x00000400

    // Is there video information?
    vbe_info: bool,         // 0x00000800
    framebuffer_info: bool, // 0x00001000

    unused: u19,
};

comptime {
    assert(@bitSizeOf(InfoFlags) == 32);
}

pub const Info = packed struct {
    flags: InfoFlags align(4),
    mem_lower: u32,
    mem_upper: u32,
    boot_device: packed struct {
        part3: u8,
        part2: u8,
        part1: u8,
        drive: u8,
    },
    cmdline: [*:0]const u8,
    mods_count: u32,
    mods_addr: [*]const u8,
    syms: packed union {
        aout_sym: packed struct {
            tabsize: u32,
            strsize: u32,
            addr: u32,
            reserved: u32,
        },
        elf_sec: packed struct {
            num: u32,
            size: u32,
            addr: u32,
            shndx: u32,
        },
    },
    mmap_length: u32,
    mmap_addr: [*]const u8,
    drives_length: u32,
    drives_addr: [*]const u8,
    config_table: u32,
    boot_loader_name: u32,
    apm_table: u32,
    vbe_control_info: u32,
    vbe_mode_info: u32,
    vbe_mode: u16,
    vbe_interface_seg: u16,
    vbe_interface_off: u16,
    vbe_interface_len: u16,
    framebuffer_addr: u64,
    framebuffer_pitch: u32,
    framebuffer_width: u32,
    framebuffer_height: u32,
    framebuffer_bpp: u8,
    framebuffer_type: u8,
    color_info: packed union {
        indexed: packed struct {
            framebuffer_palette_addr: u32,
            framebuffer_palette_num_colors: u16,
        },
        rgb: packed struct {
            framebuffer_red_field_position: u8,
            framebuffer_red_mask_size: u8,
            framebuffer_green_field_position: u8,
            framebuffer_green_mask_size: u8,
            framebuffer_blue_field_position: u8,
            framebuffer_blue_mask_size: u8,
        },
        ega_text: void,
    },
};

comptime {
    assert(@byteOffsetOf(Info, "flags") == 0);
    assert(@byteOffsetOf(Info, "mem_lower") == 4);
    assert(@byteOffsetOf(Info, "mem_upper") == 8);
    assert(@byteOffsetOf(Info, "boot_device") == 12);
    assert(@byteOffsetOf(Info, "cmdline") == 16);
    assert(@byteOffsetOf(Info, "mods_count") == 20);
    assert(@byteOffsetOf(Info, "mods_addr") == 24);
    assert(@byteOffsetOf(Info, "syms") == 28);
    assert(@byteOffsetOf(Info, "mmap_length") == 44);
    assert(@byteOffsetOf(Info, "mmap_addr") == 48);
    assert(@byteOffsetOf(Info, "drives_length") == 52);
    assert(@byteOffsetOf(Info, "drives_addr") == 56);
    assert(@byteOffsetOf(Info, "config_table") == 60);
    assert(@byteOffsetOf(Info, "boot_loader_name") == 64);
    assert(@byteOffsetOf(Info, "apm_table") == 68);
    assert(@byteOffsetOf(Info, "vbe_control_info") == 72);
    assert(@byteOffsetOf(Info, "vbe_mode_info") == 76);
    assert(@byteOffsetOf(Info, "vbe_mode") == 80);
    assert(@byteOffsetOf(Info, "vbe_interface_seg") == 82);
    assert(@byteOffsetOf(Info, "vbe_interface_off") == 84);
    assert(@byteOffsetOf(Info, "vbe_interface_len") == 86);
    assert(@byteOffsetOf(Info, "framebuffer_addr") == 88);
    assert(@byteOffsetOf(Info, "framebuffer_pitch") == 96);
    assert(@byteOffsetOf(Info, "framebuffer_width") == 100);
    assert(@byteOffsetOf(Info, "framebuffer_height") == 104);
    assert(@byteOffsetOf(Info, "framebuffer_bpp") == 108);
    assert(@byteOffsetOf(Info, "framebuffer_type") == 109);
    assert(@byteOffsetOf(Info, "color_info") == 110);

    // Extra 4 bytes of padding?
    assert(@sizeOf(Info) == 116 + 4);
}