ds_rom/rom/
header.rs

1use std::{
2    mem::{offset_of, size_of},
3    str::FromStr,
4};
5
6use serde::{Deserialize, Serialize};
7use snafu::Snafu;
8
9use super::{
10    raw::{
11        self, AccessControl, Capacity, Delay, DsFlags, DsiFlags, DsiFlags2, HeaderVersion, ProgramOffset, RegionFlags,
12        TableOffset,
13    },
14    BuildContext, Rom,
15};
16use crate::{
17    crc::CRC_16_MODBUS,
18    str::{AsciiArray, AsciiArrayError},
19};
20/// ROM header.
21#[derive(Serialize, Deserialize, Default)]
22pub struct Header {
23    /// Values for the original header version, [`HeaderVersion::Original`].
24    #[serde(flatten)]
25    pub original: HeaderOriginal,
26    /// Values for DS games after DSi release, [`HeaderVersion::DsPostDsi`].
27    #[serde(skip_serializing_if = "Option::is_none")]
28    pub ds_post_dsi: Option<HeaderDsPostDsi>,
29}
30
31/// Values for the original header version, [`HeaderVersion::Original`].
32#[derive(Serialize, Deserialize, Default)]
33pub struct HeaderOriginal {
34    /// Short game title, normally in uppercase letters.
35    pub title: String,
36    /// 4-character game code in uppercase letters.
37    pub gamecode: AsciiArray<4>,
38    /// 2-character maker code, normally "01".
39    pub makercode: AsciiArray<2>,
40    /// Unit code, depends on which platform (DS, DSi) this game is for.
41    pub unitcode: u8,
42    /// Encryption seed select.
43    pub seed_select: u8,
44    /// Flags for both DS and DSi.
45    pub ds_flags: DsFlags,
46    /// Autostart, can skip "Health and Safety" screen.
47    pub autostart: u8,
48    /// Port 0x40001a4 setting for normal commands.
49    pub normal_cmd_setting: u32,
50    /// Port 0x40001a4 setting for KEY1 commands.
51    pub key1_cmd_setting: u32,
52    /// Delay to wait for secure area.
53    pub secure_area_delay: Delay,
54    /// NAND end of ROM area in multiples of 0x20000 (0x80000 on DSi).
55    pub rom_nand_end: u16,
56    /// NAND end of RW area in multiples of 0x20000 (0x80000 on DSi).
57    pub rw_nand_end: u16,
58    /// Whether the header has the ARM9 build info offset.
59    pub has_arm9_build_info_offset: bool,
60}
61
62/// Values for DS games after DSi release, [`HeaderVersion::DsPostDsi`].
63#[derive(Serialize, Deserialize)]
64pub struct HeaderDsPostDsi {
65    /// DSi-exclusive flags.
66    pub dsi_flags_2: DsiFlags2,
67    /// SHA1-HMAC of banner.
68    pub sha1_hmac_banner: [u8; 0x14],
69    /// Unknown SHA1-HMAC, defined by some games.
70    pub sha1_hmac_unk1: [u8; 0x14],
71    /// Unknown SHA1-HMAC, defined by some games.
72    pub sha1_hmac_unk2: [u8; 0x14],
73    /// RSA-SHA1 signature up to [`raw::Header::debug_args`].
74    pub rsa_sha1: Box<[u8]>,
75}
76
77/// Errors related to [`Header::build`].
78#[derive(Snafu, Debug)]
79pub enum HeaderBuildError {
80    /// See [`AsciiArrayError`].
81    #[snafu(transparent)]
82    AsciiArray {
83        /// Source error.
84        source: AsciiArrayError,
85    },
86}
87
88impl Header {
89    /// Loads from a raw header.
90    pub fn load_raw(header: &raw::Header) -> Self {
91        let version = header.version();
92        Self {
93            original: HeaderOriginal {
94                title: header.title.to_string(),
95                gamecode: header.gamecode,
96                makercode: header.makercode,
97                unitcode: header.unitcode,
98                seed_select: header.seed_select,
99                ds_flags: header.ds_flags,
100                autostart: header.autostart,
101                normal_cmd_setting: header.normal_cmd_setting,
102                key1_cmd_setting: header.key1_cmd_setting,
103                secure_area_delay: header.secure_area_delay,
104                rom_nand_end: header.rom_nand_end,
105                rw_nand_end: header.rw_nand_end,
106                has_arm9_build_info_offset: header.arm9_build_info_offset != 0,
107            },
108            ds_post_dsi: (version >= HeaderVersion::DsPostDsi).then_some(HeaderDsPostDsi {
109                dsi_flags_2: header.dsi_flags_2,
110                sha1_hmac_banner: header.sha1_hmac_banner,
111                sha1_hmac_unk1: header.sha1_hmac_unk1,
112                sha1_hmac_unk2: header.sha1_hmac_unk2,
113                rsa_sha1: Box::new(header.rsa_sha1),
114            }),
115        }
116    }
117
118    /// Builds a raw header.
119    ///
120    /// # Panics
121    ///
122    /// Panics if a value is missing in the `context`.
123    ///
124    /// # Errors
125    ///
126    /// This function will return an error if the title contains a non-ASCII character.
127    pub fn build(&self, context: &BuildContext, rom: &Rom) -> Result<raw::Header, HeaderBuildError> {
128        let logo = rom.header_logo().compress();
129        let arm9 = rom.arm9();
130        let arm7 = rom.arm7();
131        let arm9_offset = context.arm9_offset.expect("ARM9 offset must be known");
132        let arm7_offset = context.arm7_offset.expect("ARM7 offset must be known");
133        let mut header = raw::Header {
134            title: AsciiArray::from_str(&self.original.title)?,
135            gamecode: self.original.gamecode,
136            makercode: self.original.makercode,
137            unitcode: self.original.unitcode,
138            seed_select: self.original.seed_select,
139            capacity: Capacity::from_size(context.rom_size.expect("ROM size must be known")),
140            reserved0: [0; 7],
141            dsi_flags: DsiFlags::new(),
142            ds_flags: self.original.ds_flags,
143            rom_version: 0,
144            autostart: self.original.autostart,
145            arm9: ProgramOffset {
146                offset: arm9_offset,
147                entry: arm9.entry_function(),
148                base_addr: arm9.base_address(),
149                size: arm9.full_data().len() as u32,
150            },
151            arm7: ProgramOffset {
152                offset: arm7_offset,
153                entry: arm7.entry_function(),
154                base_addr: arm7.base_address(),
155                size: arm7.full_data().len() as u32,
156            },
157            file_names: context.fnt_offset.expect("FNT offset must be known"),
158            file_allocs: context.fat_offset.expect("FAT offset must be known"),
159            arm9_overlays: context.arm9_ovt_offset.unwrap_or_default(),
160            arm7_overlays: context.arm7_ovt_offset.unwrap_or_default(),
161            normal_cmd_setting: self.original.normal_cmd_setting,
162            key1_cmd_setting: self.original.key1_cmd_setting,
163            banner_offset: context.banner_offset.map(|b| b.offset).expect("Banner offset must be known"),
164            secure_area_crc: if let Some(key) = context.blowfish_key {
165                arm9.secure_area_crc(key, self.original.gamecode.to_le_u32())
166            } else {
167                0
168            },
169            secure_area_delay: self.original.secure_area_delay,
170            arm9_autoload_callback: context.arm9_autoload_callback.expect("ARM9 autoload callback must be known"),
171            arm7_autoload_callback: context.arm7_autoload_callback.expect("ARM7 autoload callback must be known"),
172            secure_area_disable: 0,
173            rom_size_ds: context.rom_size.expect("ROM size must be known"),
174            header_size: size_of::<raw::Header>() as u32,
175            arm9_build_info_offset: if self.original.has_arm9_build_info_offset {
176                context.arm9_build_info_offset.map(|offset| offset + arm9_offset).unwrap_or(0)
177            } else {
178                0
179            },
180            arm7_build_info_offset: context.arm7_build_info_offset.map(|offset| offset + arm7_offset).unwrap_or(0),
181            ds_rom_region_end: 0,
182            dsi_rom_region_end: 0,
183            rom_nand_end: self.original.rom_nand_end,
184            rw_nand_end: self.original.rw_nand_end,
185            reserved1: [0; 0x18],
186            reserved2: [0; 0x10],
187            logo,
188            logo_crc: CRC_16_MODBUS.checksum(&logo),
189            header_crc: 0, // gets updated below
190            debug_rom_offset: 0,
191            debug_size: 0,
192            debug_ram_addr: 0,
193            reserved3: [0; 0x4],
194            reserved4: [0; 0x10],
195            // The below fields are for DSi only and are not supported yet
196            memory_banks_wram: [0; 5],
197            memory_banks_arm9: [0; 3],
198            memory_banks_arm7: [0; 3],
199            memory_bank_9: 0,
200            region_flags: RegionFlags::new(),
201            access_control: AccessControl::new(),
202            arm7_scfg_ext7_setting: 0,
203            dsi_flags_2: DsiFlags2::new(),
204            arm9i: ProgramOffset::default(),
205            arm7i: ProgramOffset::default(),
206            digest_ds_area: TableOffset::default(),
207            digest_dsi_area: TableOffset::default(),
208            digest_sector_hashtable: TableOffset::default(),
209            digest_block_hashtable: TableOffset::default(),
210            digest_sector_size: 0,
211            digest_sector_count: 0,
212            banner_size: 0,
213            sd_shared2_0000_size: 0,
214            sd_shared2_0001_size: 0,
215            eula_version: 0,
216            use_ratings: false,
217            rom_size_dsi: 0,
218            sd_shared2_0002_size: 0,
219            sd_shared2_0003_size: 0,
220            sd_shared2_0004_size: 0,
221            sd_shared2_0005_size: 0,
222            arm9i_build_info_offset: 0,
223            arm7i_build_info_offset: 0,
224            modcrypt_area_1: TableOffset::default(),
225            modcrypt_area_2: TableOffset::default(),
226            gamecode_rev: AsciiArray([0; 4]),
227            file_type: 0,
228            sd_public_sav_size: 0,
229            sd_private_sav_size: 0,
230            reserved5: [0; 0xb0],
231            age_ratings: [0; 0x10],
232            sha1_hmac_arm9_with_secure_area: [0; 0x14],
233            sha1_hmac_arm7: [0; 0x14],
234            sha1_hmac_digest: [0; 0x14],
235            sha1_hmac_banner: [0; 0x14],
236            sha1_hmac_arm9i: [0; 0x14],
237            sha1_hmac_arm7i: [0; 0x14],
238            sha1_hmac_unk1: [0; 0x14],
239            sha1_hmac_unk2: [0; 0x14],
240            sha1_hmac_arm9: [0; 0x14],
241            reserved6: [0; 0xa4c],
242            debug_args: [0; 0x180],
243            rsa_sha1: [0; 0x80],
244            reserved7: [0; 0x3000],
245        };
246
247        if let Some(ds_post_dsi) = &self.ds_post_dsi {
248            header.dsi_flags_2 = ds_post_dsi.dsi_flags_2;
249            header.sha1_hmac_banner = ds_post_dsi.sha1_hmac_banner;
250            header.sha1_hmac_unk1 = ds_post_dsi.sha1_hmac_unk1;
251            header.sha1_hmac_unk2 = ds_post_dsi.sha1_hmac_unk2;
252            header.rsa_sha1.copy_from_slice(&ds_post_dsi.rsa_sha1);
253        }
254
255        header.header_crc = CRC_16_MODBUS.checksum(&bytemuck::bytes_of(&header)[0..offset_of!(raw::Header, header_crc)]);
256        Ok(header)
257    }
258
259    /// Returns the version of this [`Header`].
260    pub fn version(&self) -> HeaderVersion {
261        if self.ds_post_dsi.is_some() {
262            HeaderVersion::DsPostDsi
263        } else {
264            HeaderVersion::Original
265        }
266    }
267}
ds_rom/rom/header.rs

ds_rom/rom/
header.rs
