Merge pull request #1879 from bryanthaboi/dev

bazinga bazingo
2026-08-28 18:06:09 +02:00 · 2026-08-27 13:43:29 -04:00
parent fbaf0441ee 8e9206b612
commit 4b2e772ab2
23 changed files with 2225 additions and 148 deletions
@@ -1111,6 +1111,37 @@ own state, preserving selective control outside a battle; a wrapper that only
 owns battle presentation should return `false` only for its active battle or
 text-box state.
 `pokemon.level_visible` (RFC 0019) takes a Pokémon's level off the screens
 that print it, without moving anything else on them:
 ```lua
 mod.hooks:wrap("pokemon.level_visible", function(next, mon, ctx)
  -- ctx = { where = "battle.enemy" | "battle.player" | "party" | "summary",
  --         game = <Game> }
  if myMode.active and ctx.where ~= "party" then return false end
  return next(mon, ctx)
 end)
 ```
 It receives `(next, mon, ctx)` and defaults to `true`, so vanilla rendering
 is unchanged. Only an explicit `false` suppresses; `nil` and anything else
 print, so a wrapper that forgets a branch cannot blank a screen by accident.
 The `<LV>` glyph goes with the digits, and on status page 2 so does the
 `<to>` arrow that points at the next level, because an arrow with nothing
 after it is half a sentence. A status condition still replaces the level on
 a battle healthbox exactly as it does in the cart, so hiding a level never
 hides `PSN` or `BRN`.
 `ctx.where` names the surface rather than the widget, because the number
 means different things on different screens: on a battle HUD an opponent's
 level is information about them, on the party and status screens your own
 level is information about you. A mode can hide one and keep the other.
 **Gen 1 only for now.** The Gen 2 screens keep their own level readouts and
 do not consult this hook, and neither does the Gen 1 PC box list, where the
 level is part of a row label rather than a drawn field. Both are noted in
 RFC 0019 as follow-ups.
 `core.logic_speed` receives `(next, game)` once per `Game:logicSpeed()` call
 (once per frame). Vanilla behavior resolves the per-category GAME SPEED
 option (`GameSpeed.CATEGORIES`: overworld/battle/menu) for whichever
@@ -0,0 +1,157 @@
 # RFC 0019: `pokemon.level_visible` — a level a mode can take off the screen
 ## Status
 Proposed.
 ## Motivation
 A Pokémon's level is printed on four Gen 1 surfaces — both battle
 healthboxes, the party rows, and page 1 and page 2 of the status screen —
 and every one of them prints it unconditionally. There is no seam. A mode
 that wants the number gone has exactly two options today, and both are bad.
 It can paint over the text from `render.hud`, which means knowing four pixel
 rectangles, matching the background shade, and surviving the palette flashes
 and the healthbox slide-in. Or it can monkey-patch the drawing modules from
 inside its sandbox, which works — `require` hands a mod the engine's own
 table — and is precisely what `CONTRIBUTING-mods.md` tells mods not to do.
 A mod that took the second road already deleted its patching layer once, for
 the reasons that document gives.
 The motivating case is a battle royale where every party is scaled to a
 shared rung that rises with the fog. The number on the healthbox is
 therefore never news — it is the same for everyone, it changes on a clock,
 and a player reading `:L37` on an opponent learns nothing except that they
 are playing the same match. Worse, it reads as a threat it is not: a Lv37
 opponent looks dangerous to a player who has not worked out that their own
 team is Lv37 too. The mode wants the level off the HUD and out of the party
 list, and the announcement it replaces it with is one line about everyone
 getting stronger at once.
 Nothing about that is specific to a battle royale. A randomizer that hides
 levels to keep an encounter unreadable, a challenge run that forbids
 level-checking, a hard mode that withholds an opponent's level, and a
 "blind" Nuzlocke all want the same switch, and none of them should have to
 learn where the `<LV>` glyph lives.
 ## The decision it extends
 This extends the **additive, guarded seam convention** Route B in
 `CONTRIBUTING-mods.md` documents, and is gated by the parity guarantee
 `tests/engine/gate_meta_coverage.lua` enforces.
 It sits with the presentation predicates already on the battle screen —
 `battle.status_hud_visible`, `battle.bottom_ui_visible` and
 `battle.caught_marker_visible` — and takes the same shape: a hook consulted
 behind `Runtime.wantsHook`, defaulting to visible, where only an explicit
 `false` suppresses. The difference is that a level is not a battle-only
 readout, so this one is not named `battle.*` and carries the surface that
 asked.
 There is no in-repo D-number registry to amend.
 ## Exact API delta
 ### New hook: `pokemon.level_visible`
 ```lua
 mod.hooks:wrap("pokemon.level_visible", function(next, mon, ctx)
  -- ctx = { where = "battle.enemy" | "battle.player" | "party" | "summary",
  --         game = <Game> }
  if myMode.active and ctx.where ~= "party" then
    return false      -- the level is not printed on that surface
  end
  return next(mon, ctx)   -- true: printed, as today
 end)
 ```
 Default `true`. Only an explicit `false` suppresses; `nil` and every other
 value print, so a wrapper that forgets a branch cannot blank a screen by
 accident.
 `ctx.where` names the surface rather than the widget, because the number
 means different things on different screens: on a battle HUD an opponent's
 level is information about *them*, on the party and status screens your own
 level is information about *you*. A mode that wants to hide the first and
 keep the second can, and the motivating mode does exactly that.
 ### New module: `src/ui/LevelDisplay.lua`
 One function, `LevelDisplay.visible(mon, where, game)`, wrapping the
 `wantsHook`/`call` pair. It exists so the four call sites are a one-line
 guard each instead of four copies of the same five lines, and so the hook
 has one definition of "visible" rather than four that can drift.
 ### Call sites
 | Surface | File | `where` |
 | --- | --- | --- |
 | Enemy healthbox | `src/battle/BattleState.lua` | `battle.enemy` |
 | Player healthbox | `src/battle/BattleState.lua` | `battle.player` |
 | Party rows | `src/ui/PartyMenu.lua` | `party` |
 | Status page 1 and 2 | `src/ui/SummaryMenu.lua` | `summary` |
 No layout moves. Each site keeps its own hand-rolled PrintLevel rule
 (`home/pokemon.asm:335-345` — the `<LV>` tile, then the digits, with a level
 of 100 writing its third digit back over the tile); it just asks first.
 Two details are deliberate:
 - **A status condition still replaces the level on a healthbox**, exactly as
  it does in the cart, so hiding the level never hides `PSN` or `BRN`. The
  guard is an `elseif` on the existing status branch, not a wrapper around
  it.
 - **On status page 2 the `<to>` arrow is hidden with the level it points
  at.** The arrow introduces the next level; on its own it is half a
  sentence. The EXP-to-next-level figure beside it is a different field and
  still prints.
 ### No other surface changes
 No event, no registry, no save field, no manifest key.
 ## Migration
 None. The hook is additive and defaults to current behaviour.
 ## Verification
 - `tests/modkit/cases/pokemon_level_visible.lua` — the contract through the
  public mod API: default true with no mod, `false` suppresses, the surface
  and the mon reach the hook, falling through prints, and a `nil` mon
  answers rather than throwing.
 - `tests/engine/gate_hooks.lua` — the structural parity gate picks the hook
  up automatically, because it walks the live catalog rather than a list.
 - `tests/engine/gate_meta_coverage.lua` — the coverage ratchet; the seam is
  covered by name from the change that introduces it, so it never enters the
  DEBT ledger.
 ## Backward compatibility
 A build with no mod wrapping the hook never reaches `Runtime.call`:
 `wantsHook` is checked first, which matters because two of the four sites
 are on a per-frame draw path. Pixels are unchanged, and the parity gates
 assert it.
 ## Scope, and what is deliberately not in this change
 **Gen 1 only.** The Gen 2 screens keep their own level readouts
 (`src/ui/gen2/PartyMenu.lua`, `SummaryMenu.lua`, `BoxMenu.lua`,
 `HallOfFame.lua`) and do not consult the hook. So does the Gen 1 PC box list
 (`src/ui/BoxMenu.lua`), where the level is baked into a row label string
 rather than drawn as a field, and the box-to-PNG print path beside it.
 Those are mechanical follow-ups, held back so this change stays reviewable
 against screens that can actually be exercised here. The limitation is
 stated in `docs/modding.md` beside the hook, so a mod author reads it before
 depending on it rather than after.
 ## Compatibility seam for older engines
 There is none, and none is possible without patching: the call sites are
 mid-draw, so a mod on a stock engine cannot reach them. That is the argument
 for the seam rather than a gap around it — the alternatives available to a
 mod today are painting over the engine's own pixels or reaching into its
 render modules, and the second is the thing the mod contract exists to
 prevent.
@@ -4,7 +4,7 @@
  <name>gen1recomp</name>
  <summary>Pokémon Gen 1/2 recompilation</summary>
  <metadata_license>CC0-1.0</metadata_license>
-  <project_license>LicenseRef-proprietary</project_license>
+  <project_license>MIT</project_license>
  <developer_name>The Bois Club</developer_name>
  <description>
    <p>
@@ -14,7 +14,8 @@
    </p>
  </description>
  <launchable type="desktop-id">com.theboisclub.gen1recomp.desktop</launchable>
-  <url type="homepage">https://github.com/bryanthaboi/gen1recomp</url>
+  <url type="homepage">https://gen1re.com/</url>
  <url type="vcs-browser">https://github.com/bryanthaboi/gen1recomp</url>
  <screenshots>
    <screenshot type="default">
      <caption>Launcher</caption>
@@ -16,6 +16,7 @@ local Damage = require("src.battle.Damage")
 local EffectRegistry = require("src.battle.EffectRegistry")
 local Experience = require("src.battle.Experience")
 local Font = require("src.render.Font")
 local LevelDisplay = require("src.ui.LevelDisplay")
 local Logger = require("src.core.Logger")
 local MoveEffects = require("src.battle.MoveEffects")
 local Party = require("src.pokemon.Party")
@@ -6337,7 +6338,7 @@ function BattleState:drawHUDs(slide)
    end
    if self.enemy.shownStatus then
      Font.draw(self:statusLabel({ status = self.enemy.shownStatus }), 40, 8)
-    else
+    elseif LevelDisplay.visible(self.enemy.mon, "battle.enemy", self.game) then
      hudTile(0x6E, 32, 8) -- <LV>
      Font.draw(tostring(self.enemy.mon.level), 40, 8)
    end
@@ -6421,7 +6422,7 @@ function BattleState:drawHUDs(slide)
    Font.draw(self.player.name, nameX(10, self.player.name), 56)
    if self.player.shownStatus then
      Font.draw(self:statusLabel({ status = self.player.shownStatus }), 120, 64)
-    else
+    elseif LevelDisplay.visible(self.player.mon, "battle.player", self.game) then
      hudTile(0x6E, 112, 64) -- <LV>
      Font.draw(tostring(self.player.mon.level), 120, 64)
    end
@@ -2296,8 +2296,8 @@ function RomImporter:_importRequiredSource(modId, importId, source, confirmed)
    }
    return nil
  end
-  if type(size) == "number" and size > RequiredImports.LARGE_WARN_BYTES
+  if spec.format ~= "n64" and (size == nil
-      and spec.format ~= "n64" then
+      or size > RequiredImports.LARGE_WARN_BYTES) then
    local ok, result = streamRequiredImport(manifest, importId, source)
    if ok then
      self.requiredImportNotice = nil
@@ -4266,6 +4266,7 @@ function RomImporter:_toggleSafeMode()
  self.mods = nil
  self.findInstalled = nil
  self._modSortCache = nil
  self._cartCaptureCache = nil
  self._modInfoFetch = nil
  self.modNotice = nil
 end
@@ -4592,7 +4593,7 @@ function RomImporter:_selectCart(version, id)
  self.activeCart[version] = id
  self._cartPlan = nil
  -- the MODS panel answers for the cart now, so its cached rows are stale
-  self.mods, self._modSortCache = nil, nil
+  self.mods, self._modSortCache, self._cartCaptureCache = nil, nil, nil
  local scope = self:slotScope(version)
  self.slots[scope] = nil
  self.slotScroll[scope] = nil
@@ -4891,7 +4892,11 @@ end
 -- pins the off ones too, so they are part of the cart it would write.
 function RomImporter:_cartCaptureCount(version)
  if not GameVersion.VERSIONS[version] then return 0 end
-  return #cartModRows(self, version)
+  local cache = self._cartCaptureCache
  if cache and cache.version == version then return cache.n end
  local n = #cartModRows(self, version)
  self._cartCaptureCache = { version = version, n = n }
  return n
 end
 function RomImporter:_cartAuthor()
@@ -5250,6 +5255,7 @@ function RomImporter:_refreshMods()
  local SaveData = require("src.core.SaveData")
  self._cartPlan = nil
  self._profileCache = nil
  self._cartCaptureCache = nil
  self.findInstalled = nil
  self.safeMode = SaveData.isSafeMode(SaveData.loadOptions())
  -- Once per session, ahead of the first listing: pull in any mod the player
@@ -5284,6 +5290,7 @@ function RomImporter:_refreshMods()
      if m.targetsHere ~= false then kept[#kept + 1] = m end
    end
    self.mods = kept
    self._cartCaptureCache = { version = self.modScope, n = #kept }
  end
  -- a pin is judged against the whole listing: the cart named it, so it is
  -- listed even where the game filter above would have dropped it
@@ -20,6 +20,37 @@ local GameVersion = require("src.core.GameVersion")
 local SaveFileIO = {}
 -- The cartridge image an imported Gen 2 slot came from, kept BESIDE the slot
 -- rather than inside it: export needs the regions the codec does not model,
 -- and 32 KB of binary in the serialized table is 40 KB of Lua source reparsed
 -- on every save and load.
 local function cartPath(version, slotId)
  return ("saves/%s/%s.cart"):format(version, tostring(slotId))
 end
 local function cartFs()
  local portable = SaveData.portableFs and SaveData.portableFs()
  return portable or (love and love.filesystem)
 end
 local function writeCart(version, slotId, bytes)
  local fs = cartFs()
  if not (fs and fs.write and bytes) then return end
  if fs.createDirectory then
    fs.createDirectory("saves")
    fs.createDirectory("saves/" .. version)
  end
  fs.write(cartPath(version, slotId), bytes)
 end
 local function readCart(version, slotId)
  local fs = cartFs()
  if not (fs and fs.read) then return nil end
  local ok, bytes = pcall(fs.read, cartPath(version, slotId))
  if ok and type(bytes) == "string" then return bytes end
  return nil
 end
 local SAVE_SIZE = SaveConvert.SAVE_SIZE
 -- Resolve raw save bytes from whatever the launcher hands us:
@@ -78,14 +109,17 @@ function SaveFileIO.importToSlot(source, version, force)
  version = version or GameVersion.get()
  local bytes, readErr = readSource(source)
  if not bytes then return false, readErr end
-  -- The GAME decides before the BYTES do.  Everything below this line judges a
+  -- The GAME decides before the BYTES do.  Everything below this line used to
-  -- save by Gen 1's rules -- the size test, and mainChecksumValid, which is
+  -- judge a save by Gen 1's rules whatever game it was for, and a Gen 2 cart
-  -- pokered's checksum -- so a Gen 2 cart save reaching it is measured against
+  -- is MBC3+TIMER: a real Gold/Silver/Crystal .sav carries an RTC footer, so
-  -- a rule that cannot match and comes back "checksum invalid" (#1832).
+  -- it is 32786 bytes, misses the size test, and was then measured against
  -- pokered's checksum -- which is why a perfectly good Crystal save reported
  -- as corrupt (#1832).  mainChecksumValid now takes the game and asks that
  -- generation's rule.
  local supported, unsupportedWhy = SaveConvert.importSupported(version)
  if not supported then return false, unsupportedWhy end
  if #bytes ~= SAVE_SIZE then
-    local check = SaveConvert.mainChecksumValid(bytes)
+    local check = SaveConvert.mainChecksumValid(bytes, version)
    if check == nil then
      return false, ("A save file must be %d bytes (32 KB); this one is %d.")
        :format(SAVE_SIZE, #bytes)
@@ -93,7 +127,12 @@ function SaveFileIO.importToSlot(source, version, force)
    if check == false then
      return false, "save data checksum invalid (main data checksum mismatch)"
    end
-    if #bytes > SAVE_SIZE and not force then
+    -- The confirm exists because a Gen 1 save bigger than 32768 is a surprise
    -- worth asking about.  On a Gen 2 cart it is the normal shape -- every
    -- real one has the footer -- so asking would be a prompt with one sensible
    -- answer, on every import, forever.
    if #bytes > SAVE_SIZE and not force
       and not SaveConvert.isGen2Cart(version) then
      return false, nil, { needsConfirm = true, size = #bytes }
    end
    bytes = #bytes > SAVE_SIZE and bytes:sub(1, SAVE_SIZE)
@@ -117,6 +156,7 @@ function SaveFileIO.importToSlot(source, version, force)
    return false, "could not write the imported save: " .. tostring(writeErr)
  end
  SaveData.setActiveSlot(version, slotId)
  if SaveConvert.isGen2Cart(version) then writeCart(version, slotId, bytes) end
  return true, slotId
 end
@@ -131,9 +171,10 @@ function SaveFileIO.exportActiveSlot(version)
  version = version or GameVersion.get()
  local save = SaveData.load(version)
  if not save then return false, "this game has no save to export yet" end
  local bytes, exportErr = SaveConvert.exportSav(save, version)
  if not bytes then return false, exportErr end
  local slotId = SaveData.activeSlot(version) or "save"
  local bytes, exportErr = SaveConvert.exportSav(save, version,
                                                 readCart(version, slotId))
  if not bytes then return false, exportErr end
  -- Portable mode is the same seam SaveData's own persistFs uses: when
  -- portable.txt marks the install every persistent write leaves the OS save
  -- directory for the game folder, and an export is no exception.  Writing
@@ -0,0 +1,335 @@
 -- GENERATED by tools/gen2_sram_offsets.py. Do not edit by hand.
 -- Regenerate from a pret/pokegold + pret/pokecrystal build; see that
 -- script's header for the derivation and the assertion behind it.
 local Gen2Layout = {}
 Gen2Layout.goldSilver = {
  sCheckValue1 = 0x2008,
  sCheckValue2 = 0x2D6B,
  sChecksum = 0x2D69,
  sGameData = 0x2009,
  sGameDataEnd = 0x2D69,
  wPlayerName = 0x200B,
  wPlayerID = 0x2009,
  wMoney = 0x23DB,
  wCoins = 0x23E2,
  wBadges = 0x23E4,
  wKantoBadges = 0x23E5,
  wRivalName = 0x2021,
  wMomsName = 0x2016,
  wPartyCount = 0x288A,
  wPartySpecies = 0x288B,
  wPartyMons = 0x2892,
  wPartyMonNicknames = 0x29F4,
  wPartyMonOTs = 0x29B2,
  wNumItems = 0x241F,
  wItems = 0x2420,
  wNumKeyItems = 0x2449,
  wKeyItems = 0x244A,
  wNumBalls = 0x2464,
  wBalls = 0x2465,
  wTMsHMs = 0x23E6,
  wPokedexCaught = 0x2A4C,
  wPokedexSeen = 0x2A6C,
  wCurBox = 0x2724,
  wBoxNames = 0x2727,
  wMapGroup = 0x2868,
  wMapNumber = 0x2869,
  wXCoord = 0x286B,
  wYCoord = 0x286A,
  wEventFlags = 0x261F,
  wPlayerState = 0x24EA,
  wGameTimeHours = 0x2053,
  wGameTimeMinutes = 0x2055,
  -- The 14 archived boxes, listed rather than strided (see BOX_COUNT).
  boxes = { 0x4000, 0x4450, 0x48A0, 0x4CF0, 0x5140, 0x5590, 0x59E0, 0x6000, 0x6450, 0x68A0, 0x6CF0, 0x7140, 0x7590, 0x79E0 },
 }
 Gen2Layout.crystal = {
  sCheckValue1 = 0x2008,
  sCheckValue2 = 0x2D0F,
  sChecksum = 0x2D0D,
  sGameData = 0x2009,
  sGameDataEnd = 0x2B83,
  wPlayerName = 0x200B,
  wPlayerID = 0x2009,
  wMoney = 0x23DC,
  wCoins = 0x23E3,
  wBadges = 0x23E5,
  wKantoBadges = 0x23E6,
  wRivalName = 0x2021,
  wMomsName = 0x2016,
  wPartyCount = 0x2865,
  wPartySpecies = 0x2866,
  wPartyMons = 0x286D,
  wPartyMonNicknames = 0x29CF,
  wPartyMonOTs = 0x298D,
  wNumItems = 0x2420,
  wItems = 0x2421,
  wNumKeyItems = 0x244A,
  wKeyItems = 0x244B,
  wNumBalls = 0x2465,
  wBalls = 0x2466,
  wTMsHMs = 0x23E7,
  wPokedexCaught = 0x2A27,
  wPokedexSeen = 0x2A47,
  wCurBox = 0x2700,
  wBoxNames = 0x2703,
  wMapGroup = 0x2843,
  wMapNumber = 0x2844,
  wXCoord = 0x2846,
  wYCoord = 0x2845,
  wEventFlags = 0x2600,
  wPlayerState = 0x24EB,
  wGameTimeHours = 0x2052,
  wGameTimeMinutes = 0x2054,
  -- The 14 archived boxes, listed rather than strided (see BOX_COUNT).
  boxes = { 0x4000, 0x4450, 0x48A0, 0x4CF0, 0x5140, 0x5590, 0x59E0, 0x6000, 0x6450, 0x68A0, 0x6CF0, 0x7140, 0x7590, 0x79E0 },
  -- The backup copy the game falls back to when the primary
  -- checksum fails. Same shape, shifted.
  backup = {
    sCheckValue1 = 0x1208,
    sCheckValue2 = 0x1F0F,
    sChecksum = 0x1F0D,
    sGameData = 0x1209,
    sGameDataEnd = 0x1D83,
    wPlayerName = 0x120B,
    wPlayerID = 0x1209,
    wMoney = 0x15DC,
    wCoins = 0x15E3,
    wBadges = 0x15E5,
    wKantoBadges = 0x15E6,
    wRivalName = 0x1221,
    wMomsName = 0x1216,
    wPartyCount = 0x1A65,
    wPartySpecies = 0x1A66,
    wPartyMons = 0x1A6D,
    wPartyMonNicknames = 0x1BCF,
    wPartyMonOTs = 0x1B8D,
    wNumItems = 0x1620,
    wItems = 0x1621,
    wNumKeyItems = 0x164A,
    wKeyItems = 0x164B,
    wNumBalls = 0x1665,
    wBalls = 0x1666,
    wTMsHMs = 0x15E7,
    wPokedexCaught = 0x1C27,
    wPokedexSeen = 0x1C47,
    wCurBox = 0x1900,
    wBoxNames = 0x1903,
    wMapGroup = 0x1A43,
    wMapNumber = 0x1A44,
    wXCoord = 0x1A46,
    wYCoord = 0x1A45,
    wEventFlags = 0x1800,
    wPlayerState = 0x16EB,
    wGameTimeHours = 0x1252,
    wGameTimeMinutes = 0x1254,
    boxes = { 0x4000, 0x4450, 0x48A0, 0x4CF0, 0x5140, 0x5590, 0x59E0, 0x6000, 0x6450, 0x68A0, 0x6CF0, 0x7140, 0x7590, 0x79E0 },
  },
 }
 Gen2Layout.charmap = {
  [0x05] = "ガ",
  [0x06] = "ギ",
  [0x07] = "グ",
  [0x08] = "ゲ",
  [0x09] = "ゴ",
  [0x0A] = "ザ",
  [0x0B] = "ジ",
  [0x0C] = "ズ",
  [0x0D] = "ゼ",
  [0x0E] = "ゾ",
  [0x0F] = "ダ",
  [0x10] = "ヂ",
  [0x11] = "ヅ",
  [0x12] = "デ",
  [0x13] = "ド",
  [0x19] = "バ",
  [0x1A] = "ビ",
  [0x1B] = "ブ",
  [0x1C] = "ボ",
  [0x26] = "が",
  [0x27] = "ぎ",
  [0x28] = "ぐ",
  [0x29] = "げ",
  [0x2A] = "ご",
  [0x2B] = "ざ",
  [0x2C] = "じ",
  [0x2D] = "ず",
  [0x2E] = "ぜ",
  [0x2F] = "ぞ",
  [0x30] = "だ",
  [0x31] = "ぢ",
  [0x32] = "づ",
  [0x33] = "で",
  [0x34] = "ど",
  [0x3A] = "ば",
  [0x3B] = "び",
  [0x3C] = "ぶ",
  [0x3D] = "べ",
  [0x3E] = "ぼ",
  [0x3F] = "⁂",
  [0x40] = "パ",
  [0x41] = "ピ",
  [0x42] = "プ",
  [0x43] = "ポ",
  [0x44] = "ぱ",
  [0x45] = "ぴ",
  [0x46] = "ぷ",
  [0x47] = "ぺ",
  [0x48] = "ぽ",
  [0x50] = "@",
  [0x54] = "#",
  [0x60] = "■",
  [0x61] = "▲",
  [0x62] = "☎",
  [0x6E] = "ぃ",
  [0x6F] = "ぅ",
  [0x70] = "PO",
  [0x71] = "KE",
  [0x72] = "“",
  [0x73] = "”",
  [0x74] = "·",
  [0x75] = "…",
  [0x76] = "ぁ",
  [0x77] = "ぇ",
  [0x78] = "ぉ",
  [0x79] = "┌",
  [0x7A] = "─",
  [0x7B] = "┐",
  [0x7C] = "│",
  [0x7D] = "└",
  [0x7E] = "┘",
  [0x7F] = " ",
  [0x80] = "A",
  [0x81] = "B",
  [0x82] = "C",
  [0x83] = "D",
  [0x84] = "E",
  [0x85] = "F",
  [0x86] = "G",
  [0x87] = "H",
  [0x88] = "I",
  [0x89] = "J",
  [0x8A] = "K",
  [0x8B] = "L",
  [0x8C] = "M",
  [0x8D] = "N",
  [0x8E] = "O",
  [0x8F] = "P",
  [0x90] = "Q",
  [0x91] = "R",
  [0x92] = "S",
  [0x93] = "T",
  [0x94] = "U",
  [0x95] = "V",
  [0x96] = "W",
  [0x97] = "X",
  [0x98] = "Y",
  [0x99] = "Z",
  [0x9A] = "(",
  [0x9B] = ")",
  [0x9C] = ":",
  [0x9D] = ";",
  [0x9E] = "[",
  [0x9F] = "]",
  [0xA0] = "a",
  [0xA1] = "b",
  [0xA2] = "c",
  [0xA3] = "d",
  [0xA4] = "e",
  [0xA5] = "f",
  [0xA6] = "g",
  [0xA7] = "h",
  [0xA8] = "i",
  [0xA9] = "j",
  [0xAA] = "k",
  [0xAB] = "l",
  [0xAC] = "m",
  [0xAD] = "n",
  [0xAE] = "o",
  [0xAF] = "p",
  [0xB0] = "q",
  [0xB1] = "r",
  [0xB2] = "s",
  [0xB3] = "t",
  [0xB4] = "u",
  [0xB5] = "v",
  [0xB6] = "w",
  [0xB7] = "x",
  [0xB8] = "y",
  [0xB9] = "z",
  [0xBA] = "こ",
  [0xBB] = "さ",
  [0xBC] = "し",
  [0xBD] = "す",
  [0xBE] = "せ",
  [0xBF] = "そ",
  [0xC0] = "Ä",
  [0xC1] = "Ö",
  [0xC2] = "Ü",
  [0xC3] = "ä",
  [0xC4] = "ö",
  [0xC5] = "ü",
  [0xC6] = "に",
  [0xC7] = "ぬ",
  [0xC8] = "ね",
  [0xC9] = "の",
  [0xCA] = "は",
  [0xCB] = "ひ",
  [0xCC] = "ふ",
  [0xCD] = "へ",
  [0xCE] = "ほ",
  [0xCF] = "ま",
  [0xD0] = "'d",
  [0xD1] = "'l",
  [0xD2] = "'m",
  [0xD3] = "'r",
  [0xD4] = "'s",
  [0xD5] = "'t",
  [0xD6] = "'v",
  [0xD7] = "ら",
  [0xD8] = "り",
  [0xD9] = "る",
  [0xDA] = "れ",
  [0xDB] = "ろ",
  [0xDC] = "わ",
  [0xDD] = "を",
  [0xDE] = "ん",
  [0xDF] = "←",
  [0xE0] = "'",
  [0xE1] = "PK",
  [0xE2] = "MN",
  [0xE3] = "-",
  [0xE4] = "ﾟ",
  [0xE5] = "ﾞ",
  [0xE6] = "?",
  [0xE7] = "!",
  [0xE8] = ".",
  [0xE9] = "&",
  [0xEA] = "é",
  [0xEB] = "→",
  [0xEC] = "▷",
  [0xED] = "▶",
  [0xEE] = "▼",
  [0xEF] = "♂",
  [0xF0] = "¥",
  [0xF1] = "×",
  [0xF2] = "．",
  [0xF3] = "/",
  [0xF4] = ",",
  [0xF5] = "♀",
  [0xF6] = "0",
  [0xF7] = "1",
  [0xF8] = "2",
  [0xF9] = "3",
  [0xFA] = "4",
  [0xFB] = "5",
  [0xFC] = "6",
  [0xFD] = "7",
  [0xFE] = "8",
  [0xFF] = "9",
 }
 return Gen2Layout
@@ -0,0 +1,690 @@
 -- Vanilla Gen 2 (Gold/Silver/Crystal) raw SRAM <-> src/core/gen2/Save.lua.
 -- Companion to GenSave.lua, which is Gen 1 only.
 --
 -- Offsets come from Gen2Layout.lua, generated by tools/gen2_sram_offsets.py.
 -- Gold and Silver share a layout; Crystal does not.
 --
 -- Pure Lua, no love.* at require time, same as GenSave.
 local Gen2Layout = require("src.save_convert.Gen2Layout")
 local Gen2Save = {}
 Gen2Save.SAVE_SIZE = 32768
 Gen2Save.PARTY_STRUCT = 48
 Gen2Save.NAME_LENGTH = 11
 Gen2Save.PARTY_LENGTH = 6
 function Gen2Save.layoutFor(gameVersion)
  if gameVersion == "crystal" then return Gen2Layout.crystal end
  if gameVersion == "gold" or gameVersion == "silver" then return Gen2Layout.goldSilver end
  return nil
 end
 local function u8(b, o) return b:byte(o + 1) end
 local function be(b, o, n)
  local v = 0
  for i = 0, n - 1 do v = v * 256 + b:byte(o + i + 1) end
  return v
 end
 -- The cart's text encoding, from Gen2Layout.charmap. 0x50 terminates.
 local function text(b, o, n)
  local out = {}
  for i = 0, n - 1 do
    local c = b:byte(o + i + 1)
    if not c or c == 0x50 then break end
    out[#out + 1] = Gen2Layout.charmap[c] or "?"
  end
  return table.concat(out)
 end
 -- Both check values AND the 16-bit sum between them. A blank SRAM sums to a
 -- valid 0 == 0, so the check values are what reject it.
 function Gen2Save.checksumValid(bytes, L)
  if #bytes < Gen2Save.SAVE_SIZE then return nil end
  if u8(bytes, L.sCheckValue1) ~= 0x63 then return false end
  if u8(bytes, L.sCheckValue2) ~= 0x7F then return false end
  local sum = 0
  for i = L.sGameData, L.sGameDataEnd - 1 do sum = (sum + u8(bytes, i)) % 65536 end
  local stored = u8(bytes, L.sChecksum) + u8(bytes, L.sChecksum + 1) * 256
  return sum == stored
 end
 -- The cart stores numbers, the engine is keyed by name. Same shape
 -- GenSave.crosswalks builds for Gen 1. Without `data` the raw numbers survive.
 local function byIndex(defs)
  local out = {}
  for id, def in pairs(defs or {}) do
    if type(def) == "table" and def.index ~= nil then out[def.index] = id end
  end
  return out
 end
 local function toIndex(defs)
  local out = {}
  for id, def in pairs(defs or {}) do
    if type(def) == "table" and def.index ~= nil then out[id] = def.index end
  end
  return out
 end
 function Gen2Save.crosswalks(data)
  data = data or {}
  local items = byIndex(data.items)
  -- Maps are found by (group, number) rather than by a flat index.
  local maps = {}
  for id, def in pairs(data.maps or {}) do
    if type(def) == "table" and def.group and def.map then
      maps[def.group * 256 + def.map] = id
    end
  end
  local mapIds = {}
  for id, def in pairs(data.maps or {}) do
    if type(def) == "table" and def.group and def.map then
      mapIds[id] = { def.group, def.map }
    end
  end
  return {
    pokemon = byIndex(data.pokemon),
    moves = byIndex(data.moves),
    items = items,
    maps = maps,
    pokemonIndex = toIndex(data.pokemon),
    moveIndex = toIndex(data.moves),
    itemIndex = toIndex(data.items),
    mapIds = mapIds,
    itemDefs = data.items or {},
  }
 end
 -- Name if the crosswalk knows it, the raw number if not. Never silently drops
 -- a value: an id this build cannot name is still the player's.
 local function named(map, index)
  if index == nil or index == 0 then return nil end
  return map[index] or index
 end
 -- constants/battle_constants.asm: SLP_MASK is bits 0-2, PSN=3 BRN=4 FRZ=5
 -- PAR=6. Engine wants an ItemEffects.STATUS_CLASS key, nil when healthy.
 local STATUS_BITS = { { 3, "psn" }, { 4, "brn" }, { 5, "frz" }, { 6, "par" } }
 local function encodeStatus(name, turns)
  if name == "slp" then return math.min(math.max(turns or 1, 1), 7) end
  for _, row in ipairs(STATUS_BITS) do
    if row[2] == name then return 2 ^ row[1] end
  end
  return 0
 end
 local function decodeStatus(byte)
  local turns = byte % 8
  if turns > 0 then return "slp", turns end
  for _, row in ipairs(STATUS_BITS) do
    if math.floor(byte / 2 ^ row[1]) % 2 == 1 then return row[2], nil end
  end
  return nil, nil
 end
 -- Four DVs as nibbles in two bytes; the HP DV is rebuilt from the low bit of
 -- each (pokecrystal engine/pokemon/health.asm).
 local function decodeDVs(bytes, o)
  local hi, lo = u8(bytes, o), u8(bytes, o + 1)
  local atk = math.floor(hi / 16)
  local def = hi % 16
  local spd = math.floor(lo / 16)
  local spc = lo % 16
  local hp = (atk % 2) * 8 + (def % 2) * 4 + (spd % 2) * 2 + (spc % 2)
  return { hp = hp, attack = atk, defense = def, speed = spd, special = spc }
 end
 -- Five 16-bit stat experience words, in the cart's order.
 local function decodeStatExp(bytes, o)
  return {
    hp = be(bytes, o, 2), attack = be(bytes, o + 2, 2),
    defense = be(bytes, o + 4, 2), speed = be(bytes, o + 6, 2),
    special = be(bytes, o + 8, 2),
  }
 end
 -- The first 32 bytes, which a box mon and a party mon share.
 local function decodeSharedMon(bytes, o, x)
  local moves, pp = {}, {}
  for i = 0, 3 do
    local id = named(x.moves, u8(bytes, o + 2 + i))
    if id then moves[#moves + 1] = id end
  end
  for i = 0, 3 do pp[i + 1] = u8(bytes, o + 0x17 + i) % 64 end
  return {
    species = named(x.pokemon, u8(bytes, o)),
    item = named(x.items, u8(bytes, o + 1)),
    moves = moves, pp = pp,
    otId = be(bytes, o + 6, 2),
    experience = be(bytes, o + 8, 3),
    statExp = decodeStatExp(bytes, o + 0x0B),
    dvs = decodeDVs(bytes, o + 0x15),
    happiness = u8(bytes, o + 0x1B),
    pokerus = u8(bytes, o + 0x1C),
    caughtData = be(bytes, o + 0x1D, 2),
    level = u8(bytes, o + 0x1F),
  }
 end
 local function decodeMon(bytes, o, x)
  local mon = decodeSharedMon(bytes, o, x)
  mon.status, mon.statusTurns = decodeStatus(u8(bytes, o + 0x20))
  mon.hp = be(bytes, o + 0x22, 2)
  mon.maxHp = be(bytes, o + 0x24, 2)
  mon.stats = {
    hp = mon.maxHp,
    attack = be(bytes, o + 0x26, 2), defense = be(bytes, o + 0x28, 2),
    speed = be(bytes, o + 0x2A, 2), specialAttack = be(bytes, o + 0x2C, 2),
    specialDefense = be(bytes, o + 0x2E, 2),
  }
  return mon
 end
 -- box_struct: OTs come BEFORE nicknames, and a box mon is 32 bytes with none
 -- of the party's computed stats.
 Gen2Save.BOX_CAPACITY = 20
 Gen2Save.BOX_MON_STRUCT = 32
 local BOX_SPECIES, BOX_MONS, BOX_OTS, BOX_NICKS = 0x01, 0x16, 0x296, 0x372
 local decodeBoxMon = decodeSharedMon
 -- A count past BOX_CAPACITY means the wrong layout, not an odd save.
 function Gen2Save.decodeBoxes(bytes, L, x)
  local boxes = {}
  for index, base in ipairs(L.boxes) do
    local count = u8(bytes, base)
    if count > Gen2Save.BOX_CAPACITY then
      return nil, ("box %d reports %d Pokemon, which is impossible; this is the "
        .. "wrong layout for this save"):format(index, count)
    end
    local mons = {}
    for i = 0, count - 1 do
      local mon = decodeBoxMon(bytes, base + BOX_MONS + i * Gen2Save.BOX_MON_STRUCT, x)
      -- The species list beside the mons must agree, which is a free check
      -- on the layout.
      local listed = named(x.pokemon, u8(bytes, base + BOX_SPECIES + i))
      if listed ~= mon.species then
        return nil, ("box %d slot %d: the species list says %s and the stored "
          .. "Pokemon says %s; wrong layout for this save")
          :format(index, i + 1, tostring(listed), tostring(mon.species))
      end
      mon.ot = text(bytes, base + BOX_OTS + i * Gen2Save.NAME_LENGTH, Gen2Save.NAME_LENGTH)
      mon.nickname = text(bytes, base + BOX_NICKS + i * Gen2Save.NAME_LENGTH, Gen2Save.NAME_LENGTH)
      mons[#mons + 1] = mon
    end
    boxes[index] = mons
  end
  return boxes
 end
 -- The bag. Gen 2 splits it into four pockets, and they are not all shaped the
 -- same: ITEM and BALL are (id, quantity) pairs, KEY_ITEM is bare ids because a
 -- key item is unique, and TM_HM is a flat run of counts indexed by TM number.
 -- All of the list pockets are terminated by 0xFF as well as counted, and the
 -- count is trusted only as far as the terminator.
 -- One bag keyed by item id; PackMenu buckets it by each item's `pocket`.
 -- ITEM and BALL are (id, quantity) pairs, KEY_ITEM is bare ids.
 local function addPairs(out, bytes, countAt, listAt, cap, x)
  local n = u8(bytes, countAt)
  if n > cap then n = cap end
  for i = 0, n - 1 do
    local raw = u8(bytes, listAt + i * 2)
    if raw == 0xFF or raw == 0 then break end
    local id = named(x.items, raw)
    out[id] = (out[id] or 0) + u8(bytes, listAt + i * 2 + 1)
  end
 end
 local function addIds(out, bytes, countAt, listAt, cap, x)
  local n = u8(bytes, countAt)
  if n > cap then n = cap end
  for i = 0, n - 1 do
    local raw = u8(bytes, listAt + i)
    if raw == 0xFF or raw == 0 then break end
    local id = named(x.items, raw)
    out[id] = (out[id] or 0) + 1
  end
 end
 -- TM_HM is a flat run of counts indexed by TM number.
 local function addMachines(out, bytes, at, x, items)
  local byNumber = {}
  for id, def in pairs(items or {}) do
    if type(def) == "table" and def.tmNumber then byNumber[def.tmNumber] = id end
  end
  for number, id in pairs(byNumber) do
    local count = u8(bytes, at + number - 1)
    if count > 0 then out[id] = (out[id] or 0) + count end
  end
 end
 -- Byte index -> byte, which is what Save.scrubEvents validates.
 local function decodeFlagBytes(bytes, at, count)
  local out = {}
  for i = 0, count - 1 do out[i] = u8(bytes, at + i) end
  return out
 end
 -- A set keyed by species id: save.pokedex.caught[species] = true.
 local function decodeDex(bytes, at, x)
  local out = {}
  for i = 0, Gen2Save.NUM_SPECIES - 1 do
    local byte = u8(bytes, at + math.floor(i / 8))
    if math.floor(byte / (2 ^ (i % 8))) % 2 == 1 then
      out[named(x.pokemon, i + 1) or (i + 1)] = true
    end
  end
  return out
 end
 -- Badges by NAME, which is how FieldMoves.hasBadge and Battle:hasBadge read
 -- them. Bit position is accepted as a fallback key there, but the name is the
 -- primary and is what a save written by this project carries.
 Gen2Save.JOHTO_BADGES = {
  "ZEPHYR", "HIVE", "PLAIN", "FOG", "MINERAL", "STORM", "GLACIER", "RISING",
 }
 Gen2Save.KANTO_BADGES = {
  "BOULDER", "CASCADE", "THUNDER", "RAINBOW",
  "SOUL", "MARSH", "VOLCANO", "EARTH",
 }
 local function decodeBadges(byte, order)
  local out = {}
  for bit, name in ipairs(order) do
    if math.floor(byte / (2 ^ (bit - 1))) % 2 == 1 then out[name] = true end
  end
  return out
 end
 Gen2Save.NUM_SPECIES = 251
 Gen2Save.EVENT_BYTES = 256
 -- decode(bytes, gameVersion, data) -> partial save table, err
 function Gen2Save.decode(bytes, gameVersion, data)
  local L = Gen2Save.layoutFor(gameVersion)
  if not L then return nil, "no Gen 2 layout for " .. tostring(gameVersion) end
  if type(bytes) ~= "string" or #bytes < Gen2Save.SAVE_SIZE then
    return nil, ("save must be at least %d bytes"):format(Gen2Save.SAVE_SIZE)
  end
  -- TryLoadSaveFile falls back to VerifyBackupChecksum and loads the backup
  -- copy, so a save the real cartridge would open must not be refused here.
  -- Crystal's backup is contiguous and laid out like the primary; Gold and
  -- Silver split theirs across three sections and have none to offer.
  if Gen2Save.checksumValid(bytes, L) ~= true then
    if L.backup and Gen2Save.checksumValid(bytes, L.backup) == true then
      L = L.backup
    else
      return nil, "save data checksum invalid (Gen 2 check values or sum mismatch)"
    end
  end
  local x = Gen2Save.crosswalks(data)
  local count = u8(bytes, L.wPartyCount)
  if count > Gen2Save.PARTY_LENGTH then
    return nil, ("party count %d is impossible; this is probably the wrong layout")
      :format(count)
  end
  local party = {}
  for i = 0, count - 1 do
    local mon = decodeMon(bytes, L.wPartyMons + i * Gen2Save.PARTY_STRUCT, x)
    mon.nickname = text(bytes, L.wPartyMonNicknames + i * Gen2Save.NAME_LENGTH,
                        Gen2Save.NAME_LENGTH)
    mon.ot = text(bytes, L.wPartyMonOTs + i * Gen2Save.NAME_LENGTH,
                  Gen2Save.NAME_LENGTH)
    party[#party + 1] = mon
  end
  local boxes, boxErr = Gen2Save.decodeBoxes(bytes, L, x)
  if not boxes then return nil, boxErr end
  local inventory = {}
  addPairs(inventory, bytes, L.wNumItems, L.wItems, 20, x)
  addIds(inventory, bytes, L.wNumKeyItems, L.wKeyItems, 25, x)
  addPairs(inventory, bytes, L.wNumBalls, L.wBalls, 12, x)
  if L.wTMsHMs then addMachines(inventory, bytes, L.wTMsHMs, x, (data or {}).items) end
  return {
    generation = 2,
    version = gameVersion,
    player = {
      name = text(bytes, L.wPlayerName, Gen2Save.NAME_LENGTH),
      id = be(bytes, L.wPlayerID, 2),
      money = be(bytes, L.wMoney, 3),
      coins = be(bytes, L.wCoins, 2),
      badges = decodeBadges(u8(bytes, L.wBadges), Gen2Save.JOHTO_BADGES),
      kantoBadges = decodeBadges(u8(bytes, L.wKantoBadges), Gen2Save.KANTO_BADGES),
    },
    rival = { name = text(bytes, L.wRivalName, Gen2Save.NAME_LENGTH) },
    mom = { name = text(bytes, L.wMomsName, Gen2Save.NAME_LENGTH) },
    party = party,
    boxes = boxes,
    currentBox = u8(bytes, L.wCurBox) % 16 + 1,
    inventory = inventory,
    -- Species ids, 1-based, so the set keys match save.pokedex.caught[species].
    pokedex = {
      caught = decodeDex(bytes, L.wPokedexCaught, x),
      seen = decodeDex(bytes, L.wPokedexSeen, x),
    },
    events = decodeFlagBytes(bytes, L.wEventFlags, Gen2Save.EVENT_BYTES),
    -- Save.summary does `save.position.map or save.spawn`.
    position = {
      map = x.maps[u8(bytes, L.wMapGroup) * 256 + u8(bytes, L.wMapNumber)],
      mapGroup = u8(bytes, L.wMapGroup), mapNumber = u8(bytes, L.wMapNumber),
      x = u8(bytes, L.wXCoord), y = u8(bytes, L.wYCoord),
    },
    playTime = {
      hours = be(bytes, L.wGameTimeHours, 2),
      minutes = u8(bytes, L.wGameTimeMinutes),
      seconds = 0, frames = 0,
    },
  }
 end
 -- Everything the cart does not carry comes from a fresh game, exactly as
 -- Gen 1's mergeDefaults does: the decode above models what the SRAM holds,
 -- and mail, phone contacts, the unown dex, the hall of fame and the RTC are
 -- left to the engine's own defaults rather than invented here.
 --
 -- Loaded lazily. src/core/gen2/Save.lua pulls in love.filesystem at require
 -- time, and this module has to stay require-clean for the headless CLI and
 -- the tests, same rule GenSave follows.
 function Gen2Save.mergeDefaults(decoded, gameVersion)
  local ok, Save = pcall(require, "src.core.gen2.Save")
  if not ok then return decoded end
  local base = Save.newGame({ playerName = decoded.player and decoded.player.name })
  for k, v in pairs(decoded) do base[k] = v end
  base.version = gameVersion
  return base
 end
 -- ------------------------------------------------------------------
 -- Export
 -- ------------------------------------------------------------------
 local function putU8(t, at, v) t[at] = v % 256 end
 local function putBE(t, at, v, n)
  for i = n - 1, 0, -1 do t[at + i] = v % 256; v = math.floor(v / 256) end
 end
 -- Engine id back to the cart's number. A raw number passes through, which is
 -- how a save imported without a crosswalk round trips.
 local function indexOf(map, id)
  if id == nil then return 0 end
  if type(id) == "number" then return id end
  return map[id] or 0
 end
 local function charBytes(str, i)
  local b = str:byte(i)
  if not b then return 0 end
  if b < 0x80 then return 1 end
  if b >= 0xF0 then return 4 end
  if b >= 0xE0 then return 3 end
  if b >= 0xC0 then return 2 end
  return 1
 end
 local function glyphChars(glyph)
  local n, i = 0, 1
  while i <= #glyph do i = i + charBytes(glyph, i); n = n + 1 end
  return n
 end
 -- One-CHARACTER glyphs plus PK and MN. The cart's table also carries the
 -- ligature halves PO and KE, and accepting those turns a name containing "PO"
 -- into 0x70 where the cart had a plain P. #glyph counts BYTES, so a byte test
 -- would also drop every multi-byte glyph and turn NIDORAN into NIDORAN?.
 local REVERSE = nil
 local function reverseCharmap()
  if REVERSE then return REVERSE end
  REVERSE = {}
  for code, glyph in pairs(Gen2Layout.charmap) do
    if glyphChars(glyph) == 1 then REVERSE[glyph] = code end
  end
  for code, glyph in pairs(Gen2Layout.charmap) do
    if glyph == "PK" or glyph == "MN" then REVERSE[glyph] = code end
  end
  return REVERSE
 end
 local function putText(t, at, str, n)
  local codes = reverseCharmap()
  local i, written = 1, 0
  while i <= #str and written < n - 1 do
    local two = str:sub(i, i + 1)
    if (two == "PK" or two == "MN") and codes[two] then
      t[at + written] = codes[two]; i = i + 2
    else
      local w = charBytes(str, i)
      t[at + written] = codes[str:sub(i, i + w - 1)] or 0xE6
      i = i + w
    end
    written = written + 1
  end
  t[at + written] = 0x50
 end
 local function putBadges(t, at, owned, order)
  local byte = 0
  for bit, name in ipairs(order) do
    if owned and owned[name] then byte = byte + 2 ^ (bit - 1) end
  end
  t[at] = byte
 end
 local function putSharedMon(t, o, mon, x)
  putU8(t, o, indexOf(x.pokemonIndex, mon.species))
  putU8(t, o + 1, indexOf(x.itemIndex, mon.item))
  for i = 0, 3 do
    putU8(t, o + 2 + i, indexOf(x.moveIndex, (mon.moves or {})[i + 1]))
  end
  putBE(t, o + 6, mon.otId or 0, 2)
  putBE(t, o + 8, mon.experience or 0, 3)
  local se = mon.statExp or {}
  putBE(t, o + 0x0B, se.hp or 0, 2);      putBE(t, o + 0x0D, se.attack or 0, 2)
  putBE(t, o + 0x0F, se.defense or 0, 2); putBE(t, o + 0x11, se.speed or 0, 2)
  putBE(t, o + 0x13, se.special or 0, 2)
  local d = mon.dvs or {}
  putU8(t, o + 0x15, (d.attack or 0) * 16 + (d.defense or 0))
  putU8(t, o + 0x16, (d.speed or 0) * 16 + (d.special or 0))
  for i = 0, 3 do
    putU8(t, o + 0x17 + i, (mon.ppRaw or {})[i + 1] or (mon.pp or {})[i + 1] or 0)
  end
  putU8(t, o + 0x1B, mon.happiness or 0)
  -- 0x1C-0x1E belong to the mon, not to the slot: leaving them to the template
  -- means reordering the party gives slot 1 the previous occupant's pokerus
  -- and caught data.
  putU8(t, o + 0x1C, mon.pokerus or 0)
  putBE(t, o + 0x1D, mon.caughtData or 0, 2)
  putU8(t, o + 0x1F, mon.level or 0)
 end
 -- The bag back into its four pockets, by each item's own `pocket`.
 local function putBag(t, L, inventory, x)
  local buckets = { ITEM = {}, KEY_ITEM = {}, BALL = {}, TM_HM = {} }
  for id, count in pairs(inventory or {}) do
    local def = x.itemDefs[id]
    local pocket = (type(def) == "table" and def.pocket) or "ITEM"
    if buckets[pocket] == nil then pocket = "ITEM" end
    buckets[pocket][#buckets[pocket] + 1] = { id = id, count = count, def = def }
  end
  -- By cart index, so the order is deterministic. A flat inventory has no
  -- order of its own, so the pocket order a round trip produces is stable
  -- rather than original.
  for _, list in pairs(buckets) do
    table.sort(list, function(a, b)
      return indexOf(x.itemIndex, a.id) < indexOf(x.itemIndex, b.id)
    end)
  end
  local overflow = nil
  local function writePairs(countAt, listAt, cap, list, pocket)
    if #list > cap then overflow = overflow or { pocket, #list, cap } end
    local n = math.min(#list, cap)
    putU8(t, countAt, n)
    for i = 1, n do
      putU8(t, listAt + (i - 1) * 2, indexOf(x.itemIndex, list[i].id))
      putU8(t, listAt + (i - 1) * 2 + 1, math.min(list[i].count, 99))
    end
    putU8(t, listAt + n * 2, 0xFF)
  end
  local function writeIds(countAt, listAt, cap, list, pocket)
    if #list > cap then overflow = overflow or { pocket, #list, cap } end
    local n = math.min(#list, cap)
    putU8(t, countAt, n)
    for i = 1, n do putU8(t, listAt + i - 1, indexOf(x.itemIndex, list[i].id)) end
    putU8(t, listAt + n, 0xFF)
  end
  writePairs(L.wNumItems, L.wItems, 20, buckets.ITEM, "ITEM")
  writeIds(L.wNumKeyItems, L.wKeyItems, 25, buckets.KEY_ITEM, "KEY_ITEM")
  writePairs(L.wNumBalls, L.wBalls, 12, buckets.BALL, "BALL")
  if L.wTMsHMs then
    for _, row in ipairs(buckets.TM_HM) do
      local number = type(row.def) == "table" and row.def.tmNumber
      if number then putU8(t, L.wTMsHMs + number - 1, math.min(row.count, 99)) end
    end
  end
  return overflow
 end
 local function putFlagSet(t, at, set, count, indexFor)
  for i = 0, count - 1 do
    local byteAt = at + math.floor(i / 8)
    local bit = 2 ^ (i % 8)
    local cur = t[byteAt] or 0
    local on = math.floor(cur / bit) % 2 == 1
    local want = set and set[indexFor(i)] == true
    if on ~= want then t[byteAt] = want and (cur + bit) or (cur - bit) end
  end
 end
 -- encode(save, gameVersion, template, data) -> bytes, err
 --
 -- Writes into the cartridge image the save came from: Gen 2 SRAM holds a great
 -- deal this codec does not model and the real game trusts it on CONTINUE, so a
 -- save with no image behind it is refused rather than built from nothing.
 --
 -- Only the primary copy is written. TryLoadSaveFile rewrites the backup from
 -- the primary on every successful load.
 function Gen2Save.encode(save, gameVersion, template, data)
  local L = Gen2Save.layoutFor(gameVersion)
  if not L then return nil, "no Gen 2 layout for " .. tostring(gameVersion) end
  if type(save) ~= "table" then return nil, "expected a save table" end
  if type(template) ~= "string" or #template < Gen2Save.SAVE_SIZE then
    return nil, "this save has no cartridge image to write back into, and a "
      .. "Gen 2 save built from nothing does not boot on real hardware"
  end
  local x = Gen2Save.crosswalks(data)
  local t = {}
  for i = 0, Gen2Save.SAVE_SIZE - 1 do t[i] = template:byte(i + 1) end
  local p = save.player or {}
  putText(t, L.wPlayerName, p.name or "", Gen2Save.NAME_LENGTH)
  putBE(t, L.wPlayerID, p.id or 0, 2)
  putBE(t, L.wMoney, p.money or 0, 3)
  putBE(t, L.wCoins, p.coins or 0, 2)
  putBadges(t, L.wBadges, p.badges, Gen2Save.JOHTO_BADGES)
  putBadges(t, L.wKantoBadges, p.kantoBadges, Gen2Save.KANTO_BADGES)
  putText(t, L.wRivalName, (save.rival or {}).name or "", Gen2Save.NAME_LENGTH)
  putText(t, L.wMomsName, (save.mom or {}).name or "", Gen2Save.NAME_LENGTH)
  local party = save.party or {}
  if #party > Gen2Save.PARTY_LENGTH then
    return nil, ("a party of %d cannot be written to a cartridge"):format(#party)
  end
  putU8(t, L.wPartyCount, #party)
  for i, mon in ipairs(party) do
    putU8(t, L.wPartySpecies + i - 1, indexOf(x.pokemonIndex, mon.species))
    local o = L.wPartyMons + (i - 1) * Gen2Save.PARTY_STRUCT
    putSharedMon(t, o, mon, x)
    putU8(t, o + 0x20, encodeStatus(mon.status, mon.statusTurns))
    putBE(t, o + 0x22, mon.hp or 0, 2)
    local st = mon.stats or {}
    putBE(t, o + 0x24, mon.maxHp or st.hp or 0, 2)
    putBE(t, o + 0x26, st.attack or 0, 2);  putBE(t, o + 0x28, st.defense or 0, 2)
    putBE(t, o + 0x2A, st.speed or 0, 2);   putBE(t, o + 0x2C, st.specialAttack or 0, 2)
    putBE(t, o + 0x2E, st.specialDefense or 0, 2)
    putText(t, L.wPartyMonNicknames + (i - 1) * Gen2Save.NAME_LENGTH,
            mon.nickname or "", Gen2Save.NAME_LENGTH)
    putText(t, L.wPartyMonOTs + (i - 1) * Gen2Save.NAME_LENGTH,
            mon.ot or "", Gen2Save.NAME_LENGTH)
  end
  putU8(t, L.wPartySpecies + #party, 0xFF)
  for index, base in ipairs(L.boxes) do
    local box = (save.boxes or {})[index] or {}
    if #box > Gen2Save.BOX_CAPACITY then
      return nil, ("box %d holds %d, which a cartridge cannot"):format(index, #box)
    end
    putU8(t, base, #box)
    for i, mon in ipairs(box) do
      putU8(t, base + BOX_SPECIES + i - 1, indexOf(x.pokemonIndex, mon.species))
      putSharedMon(t, base + BOX_MONS + (i - 1) * Gen2Save.BOX_MON_STRUCT, mon, x)
      putText(t, base + BOX_OTS + (i - 1) * Gen2Save.NAME_LENGTH,
              mon.ot or "", Gen2Save.NAME_LENGTH)
      putText(t, base + BOX_NICKS + (i - 1) * Gen2Save.NAME_LENGTH,
              mon.nickname or "", Gen2Save.NAME_LENGTH)
    end
    putU8(t, base + BOX_SPECIES + #box, 0xFF)
  end
  -- Refuse rather than drop. Without item defs every item buckets into ITEM,
  -- which holds 20, and a real bag is bigger than that.
  local overflow = putBag(t, L, save.inventory, x)
  if overflow then
    return nil, ("the %s pocket would need %d slots and a cartridge has %d; "
      .. "the item table for this game is needed to sort the bag")
      :format(overflow[1], overflow[2], overflow[3])
  end
  if save.currentBox then putU8(t, L.wCurBox, (save.currentBox - 1) % 16) end
  if save.boxNames and L.wBoxNames then
    for i = 1, 14 do
      putText(t, L.wBoxNames + (i - 1) * 9, save.boxNames[i] or "", 9)
    end
  end
  if save.pokedex then
    local function species(i) return x.pokemon[i + 1] or (i + 1) end
    putFlagSet(t, L.wPokedexCaught, save.pokedex.caught, Gen2Save.NUM_SPECIES, species)
    putFlagSet(t, L.wPokedexSeen, save.pokedex.seen, Gen2Save.NUM_SPECIES, species)
  end
  for i = 0, Gen2Save.EVENT_BYTES - 1 do
    local byte = (save.events or {})[i]
    if type(byte) == "number" then putU8(t, L.wEventFlags + i, byte) end
  end
  local pos = save.position
  if pos then
    local ids = pos.map and x.mapIds[pos.map]
    putU8(t, L.wMapGroup, (ids and ids[1]) or pos.mapGroup or 0)
    putU8(t, L.wMapNumber, (ids and ids[2]) or pos.mapNumber or 0)
    putU8(t, L.wXCoord, pos.x or 0)
    putU8(t, L.wYCoord, pos.y or 0)
  end
  local pt = save.playTime
  if pt then
    putBE(t, L.wGameTimeHours, pt.hours or 0, 2)
    putU8(t, L.wGameTimeMinutes, pt.minutes or 0)
  end
  putU8(t, L.sCheckValue1, 0x63)
  putU8(t, L.sCheckValue2, 0x7F)
  local sum = 0
  for i = L.sGameData, L.sGameDataEnd - 1 do sum = (sum + t[i]) % 65536 end
  putU8(t, L.sChecksum, sum % 256)
  putU8(t, L.sChecksum + 1, math.floor(sum / 256) % 256)
  local out = {}
  for i = 0, Gen2Save.SAVE_SIZE - 1 do out[i + 1] = string.char(t[i]) end
  -- Whatever followed the 32 KiB of SRAM is the cart's RTC footer. Dropping it
  -- resets the clock, which costs the player daily events and the bug contest
  -- and earns them the clock-adjustment penalty.
  return table.concat(out) .. template:sub(Gen2Save.SAVE_SIZE + 1)
 end
 return Gen2Save
@@ -21,12 +21,23 @@
 -- require alone cannot see them there (#420).
 local GenSave = require("src.save_convert.GenSave")
-local GameVersion = require("src.core.GameVersion")
+local Gen2Save = require("src.save_convert.Gen2Save")
 local SaveConvert = {}
 SaveConvert.SAVE_SIZE = GenSave.SAVE_SIZE
-SaveConvert.mainChecksumValid = GenSave.mainChecksumValid
+-- Is this a real save for THIS GAME? Dispatches on the generation, because
 -- the two do not share a rule: Gen 1 stores a complement checksum of its main
 -- data block, Gen 2 stores two check values plus a 16-bit sum. Run one over
 -- the other's bytes and the answer is always no.
 --
 -- gameVersion is optional and defaults to Gen 1's rule, which is what every
 -- caller meant before Gen 2 had a codec.
 function SaveConvert.mainChecksumValid(bytes, gameVersion)
  local L = gameVersion and Gen2Save.layoutFor(gameVersion)
  if L then return Gen2Save.checksumValid(bytes, L) end
  return GenSave.mainChecksumValid(bytes)
 end
 -- ------------------------------------------------------------------
 -- Crosswalk data loading (cached).  Mirrors src/core/Data.lua: prefer
@@ -125,6 +136,24 @@ local function loadCacheTable(gameVersion, filePath)
  return nil
 end
 -- The generated tables Gen2Save needs to turn cart numbers into the ids the
 -- engine is keyed by. Deliberately not ensureData: that one also demands Gen
 -- 1's charmap, event flags and hidden items, none of which a Gen 2 cache has
 -- or a Gen 2 save uses.
 local gen2Data = {}
 local function ensureGen2Data(gameVersion)
  local key = gameVersion or "*"
  if gen2Data[key] == nil then
    local out = {}
    for _, name in ipairs({ "pokemon", "moves", "items", "maps" }) do
      out[name] = loadCacheTable(gameVersion, "data/generated/" .. name .. ".lua")
        or (loadTable("data.generated." .. name, "data/generated/" .. name .. ".lua"))
    end
    gen2Data[key] = out
  end
  return gen2Data[key]
 end
 -- Crosswalk sets keyed by the game whose cache they came from ("*" for the
 -- require-resolved set): Yellow's tables are not Red's, so one import must
 -- never be handed the previous import's data (#420).
@@ -228,13 +257,6 @@ SaveConvert.mergeDefaults = mergeDefaults
 -- pokered's single sPlayerName..sMainDataCheckSum window), and no Gen 2
 -- codec exists yet.  Both directions answer with a plain message the
 -- launcher's save card renders as-is, instead of pushing a Gen 2 save
 -- table through Gen 1 offsets and surfacing a codec traceback.
 local function gen2CartName(gameVersion)
  if not GameVersion.VERSIONS[gameVersion] then return nil end
  if GameVersion.generation(gameVersion) ~= 2 then return nil end
  return GameVersion.info(gameVersion).displayName
 end
 -- Can a cart save for this game cross in or out at all?  Public because the
 -- launcher has to ask about the GAME before it measures the BYTES.
 --
@@ -248,19 +270,22 @@ end
 -- Returns true, or false plus the same sentence importSav/exportSav would have
 -- answered with, so a caller that asks early and a caller that does not cannot
 -- describe the same game two different ways.
 -- Does this game use a Gen 2 cart save?  The RTC footer that follows one is
 -- expected rather than surprising, which the import path needs to know.
 function SaveConvert.isGen2Cart(gameVersion)
  return Gen2Save.layoutFor(gameVersion) ~= nil
 end
 function SaveConvert.importSupported(gameVersion)
-  local gen2Name = gen2CartName(gameVersion)
+  -- Gen 2 imports through Gen2Save now. Kept as a predicate rather than
-  if gen2Name then
+  -- deleted: SaveFileIO asks it before it measures the bytes, and export
-    return false, gen2Name .. " uses a Gen 2 cart save; importing one is not supported yet."
+  -- still answers no.
  end
  return true
 end
 -- Gen 2 exports through Gen2Save now, but only for a save with a cartridge
 -- image behind it; encode says so itself.
 function SaveConvert.exportSupported(gameVersion)
  local gen2Name = gen2CartName(gameVersion)
  if gen2Name then
    return false, gen2Name .. " uses a Gen 2 cart save; exporting one is not supported yet."
  end
  return true
 end
@@ -278,6 +303,15 @@ function SaveConvert.importSav(bytes, version, gameVersion)
  end
  local supported, unsupportedWhy = SaveConvert.importSupported(gameVersion)
  if not supported then return nil, unsupportedWhy end
  -- Gen 2 is a different SRAM entirely: different bank map, different party
  -- struct, its own check values. Gen2Save owns it, and it needs no crosswalk
  -- tables because it decodes ids the engine already speaks.
  if Gen2Save.layoutFor(gameVersion) then
    local decoded, gen2Err = Gen2Save.decode(bytes, gameVersion,
                                             ensureGen2Data(gameVersion))
    if not decoded then return nil, gen2Err end
    return Gen2Save.mergeDefaults(decoded, gameVersion)
  end
  if #bytes ~= GenSave.SAVE_SIZE then
    return nil, ("save must be %d bytes, got %d"):format(GenSave.SAVE_SIZE, #bytes)
  end
@@ -300,18 +334,23 @@ function SaveConvert.importSav(bytes, version, gameVersion)
  return mergeDefaults(decoded, version)
 end
-- exportSav(saveTable, gameVersion) -> bytes, err
+-- exportSav(saveTable, gameVersion, cartImage) -> bytes, err
 -- Encodes a save table back to a raw 32768-byte SRAM image. Template-aware:
 -- if the table still carries the stashed import template (saveTable.rawImport)
 -- GenSave reproduces every unmodeled region from it; otherwise those regions
 -- are zero-filled. gameVersion selects the crosswalk tables exactly as in
 -- importSav. On failure returns nil + a message (never raises).
-function SaveConvert.exportSav(saveTable, gameVersion)
+function SaveConvert.exportSav(saveTable, gameVersion, cartImage)
  if type(saveTable) ~= "table" then
    return nil, "expected a save table"
  end
  local supported, unsupportedWhy = SaveConvert.exportSupported(gameVersion)
  if not supported then return nil, unsupportedWhy end
  -- Gen 2 has its own SRAM and its own codec, and needs no Gen 1 crosswalks.
  if Gen2Save.layoutFor(gameVersion) then
    return Gen2Save.encode(saveTable, gameVersion, cartImage,
                           ensureGen2Data(gameVersion))
  end
  local data, derr = ensureData(gameVersion)
  if not data then return nil, derr end
  local ok, bytes = pcall(GenSave.encode, saveTable, data, nil)
@@ -0,0 +1,33 @@
 -- Whether a Pokémon's level is printed on a screen that would normally
 -- print it (RFC 0019).
 --
 -- Every Gen 1 screen that shows a level does it with the same pokered rule
 -- -- home/pokemon.asm:335-345 PrintLevel: the <LV> tile, then the digits
 -- left-aligned after it, with a level of 100 writing its third digit back
 -- over the tile -- and each screen hand-rolls that rule against its own
 -- coordinates. This module does not touch any of that. It answers one
 -- question, in one place, so that a mode which wants the number off does
 -- not have to know four call sites and a glyph code.
 --
 -- Default is true, and `Runtime.wantsHook` is checked first, so a build
 -- with no mod wrapping the hook prints exactly what it always did and pays
 -- nothing for the seam on a per-frame draw path.
 --
 -- `where` names the surface rather than the widget, because the number
 -- means different things on different screens: on the battle HUD an
 -- opponent's level is information about them, on the party and status
 -- screens your own level is information about you. A mode can hide one and
 -- keep the other.
 local Runtime = require("src.mods.Runtime")
 local LevelDisplay = {}
 -- where: "battle.enemy" | "battle.player" | "party" | "summary"
 function LevelDisplay.visible(mon, where, game)
  if not Runtime.wantsHook("pokemon.level_visible") then return true end
  return Runtime.call("pokemon.level_visible", function() return true end,
                      mon, { where = where, game = game }) ~= false
 end
 return LevelDisplay
@@ -11,6 +11,7 @@
 local Assets = require("src.render.Assets")
 local Font = require("src.render.Font")
 local LevelDisplay = require("src.ui.LevelDisplay")
 local Logger = require("src.core.Logger")
 local Runtime = require("src.mods.Runtime")
 local Screens = require("src.ui.Screens")
@@ -794,7 +795,11 @@ function PartyMenu:draw()
    -- level at column 13 (<LV> tile + digits, PrintLevel) AND the
    -- status/FNT text at column 17 (PrintStatusCondition), like the
    -- original rows -- statused mons keep their level display
-    if mon.level < 100 then
+    if not LevelDisplay.visible(mon, "party", self.game) then -- RFC 0019
      -- the level column is simply empty; the status/FNT column at 17 is a
      -- separate field and still prints, exactly as it does for a mon whose
      -- level is on screen
    elseif mon.level < 100 then
      HudTiles.tile(0x6E, 104, y) -- <LV>
      Font.draw(tostring(mon.level), 112, y)
    else
@@ -12,6 +12,7 @@ local Font = require("src.render.Font")
 -- TypeChart.displayName maps it back to "PSYCHIC", like HallOfFame and the
 -- battle move-type box already do (#214).
 local TypeChart = require("src.battle.TypeChart")
 local LevelDisplay = require("src.ui.LevelDisplay")
 local Strings = require("src.core.Strings")
 local Stats = require("src.pokemon.Stats")
 local Status = require("src.battle.Status")
@@ -137,7 +138,9 @@ function SummaryMenu:draw()
  if self.page == 1 then
    -- level is page 1 only: StatusScreen2 opens with ClearScreenArea over
    -- (9,2) 5x10 (status_screen.asm:303-305). #280
-    printLevel(14, 2, mon.level)
+    if LevelDisplay.visible(mon, "summary", self.game) then -- RFC 0019
      printLevel(14, 2, mon.level)
    end
    drawLineBox(19, 1, 6, 10)
    -- engine/pokemon/status_screen.asm:120-125
    local PaletteFX = require("src.render.PaletteFX")
@@ -196,8 +199,12 @@ function SummaryMenu:draw()
    local nextExp = mon.level < 100
      and (Growth.expForLevel(def.growthRate, mon.level + 1) - mon.exp) or 0
    Font.draw(("%7d"):format(math.max(0, nextExp)), 56, 48)
-    HudTiles.statusTile(0x70, 112, 48) -- '<to>' at (14,6), was missing (#280)
+    if LevelDisplay.visible(mon, "summary", self.game) then -- RFC 0019
-    printLevel(16, 6, math.min(100, mon.level + 1))
+      -- the '<to>' arrow is half a sentence without the level it points at,
      -- so the pair is hidden together
      HudTiles.statusTile(0x70, 112, 48) -- '<to>' at (14,6), was missing (#280)
      printLevel(16, 6, math.min(100, mon.level + 1))
    end
    Font.drawBox(0, 8, 20, 10)
    for i = 1, 4 do
      local mv = mon.moves[i]
@@ -21,5 +21,13 @@ local xml = meta:read("*a")
 meta:close()
 check(xml:find("<releases>", 1, true), "AppStream metainfo includes releases")
 check(xml:find("<release ", 1, true), "AppStream metainfo includes a release entry")
 check(xml:find("<project_license>MIT</project_license>", 1, true),
  "AppStream metainfo declares MIT project license")
 check(not xml:find("LicenseRef-proprietary", 1, true),
  "AppStream metainfo must not claim proprietary")
 check(xml:find('url type="homepage">https://gen1re.com/</url>', 1, true),
  "AppStream metainfo homepage is gen1re.com")
 check(xml:find('url type="vcs-browser">https://github.com/bryanthaboi/gen1recomp</url>', 1, true),
  "AppStream metainfo vcs-browser points at the public repo")
 print("ok")
@@ -0,0 +1,386 @@
 -- Importing a Gen 2 cart save (Gold, Silver, Crystal).
 --   luajit tests/gen2_save_import_test.lua
 -- Also dofile'd by tests/run_tests.lua.
 --
 -- The save this builds is synthesized rather than checked in, the same rule
 -- tests/save_convert_tests.lua follows for Gen 1: a real .sav is personal
 -- data. Point POKEPORT_GEN2_SAV_FIXTURE at one to run the audit at the
 -- bottom against your own Gold/Silver/Crystal save.
 --
 -- Every offset under test comes from src/save_convert/Gen2Layout.lua, which
 -- tools/gen2_sram_offsets.py generates from a pret build. The reason that
 -- matters is here in miniature: Gold and Crystal disagree on almost every
 -- field, so reading one with the other's table is not a near miss, it is a
 -- party count of 133.
 package.path = "./?.lua;./?/init.lua;" .. package.path
 love = love or require("tests.love_stub")
 local T = require("tests.harness")
 local check, eq = T.check, T.eq
 local Gen2Save = require("src.save_convert.Gen2Save")
 local Gen2Layout = require("src.save_convert.Gen2Layout")
 local SaveConvert = require("src.save_convert.SaveConvert")
 local SIZE = Gen2Save.SAVE_SIZE
 -- A byte-addressable save under construction.
 local function blank()
  local b = {}
  for i = 0, SIZE - 1 do b[i] = 0 end
  return b
 end
 local function put(b, at, ...)
  local vals = { ... }
  for i, v in ipairs(vals) do b[at + i - 1] = v % 256 end
 end
 local function putName(b, at, name)
  for i = 1, #name do b[at + i - 1] = 0x80 + (name:byte(i) - 65) end
  b[at + #name] = 0x50
 end
 local function sealOne(b, L)
  b[L.sCheckValue1] = 0x63
  b[L.sCheckValue2] = 0x7F
  local sum = 0
  for i = L.sGameData, L.sGameDataEnd - 1 do sum = (sum + b[i]) % 65536 end
  b[L.sChecksum] = sum % 256
  b[L.sChecksum + 1] = math.floor(sum / 256) % 256
 end
 -- A real cart seals both copies, and the game rewrites the backup from the
 -- primary on every successful load.
 local function seal(b, L)
  if L.backup then
    for i = 0, (L.sGameDataEnd - L.sGameData) - 1 do
      b[L.backup.sGameData + i] = b[L.sGameData + i]
    end
    sealOne(b, L.backup)
  end
  sealOne(b, L)
 end
 local function pack(b)
  local out = {}
  for i = 0, SIZE - 1 do out[i + 1] = string.char(b[i]) end
  return table.concat(out)
 end
 -- A save with one known Pokemon in the party and one in box 3.
 local function build(version)
  local L = Gen2Save.layoutFor(version)
  local b = blank()
  putName(b, L.wPlayerName, "ASH")
  putName(b, L.wRivalName, "GARY")
  putName(b, L.wMomsName, "MOM")
  put(b, L.wPlayerID, 0x12, 0x34)          -- big-endian 0x1234
  put(b, L.wMoney, 0x01, 0xE2, 0x40)       -- 123456
  put(b, L.wBadges, 0x05)                  -- ZEPHYR + PLAIN
  put(b, L.wPartyCount, 1)
  put(b, L.wPartySpecies, 155)
  local mon = L.wPartyMons
  put(b, mon, 155)                         -- species
  put(b, mon + 1, 0)                       -- no held item
  put(b, mon + 2, 33, 43, 0, 0)            -- two moves
  put(b, mon + 6, 0x12, 0x34)              -- OT id
  put(b, mon + 0x15, 0x9F, 0x6A)           -- DVs: a=9 d=15 s=6 sp=10
  put(b, mon + 0x1B, 200)                  -- happiness
  put(b, mon + 0x1F, 42)                   -- level
  put(b, mon + 0x20, 0x10)                 -- BRN (bit 4)
  put(b, mon + 0x22, 0x00, 0x64)           -- hp 100
  put(b, mon + 0x24, 0x00, 0x64)           -- maxHp 100
  put(b, mon + 0x26, 0x00, 0x37)           -- attack 55
  putName(b, L.wPartyMonNicknames, "FLAME")
  putName(b, L.wPartyMonOTs, "ASH")
  put(b, L.wMapGroup, 21); put(b, L.wMapNumber, 14)
  put(b, L.wNumItems, 1); put(b, L.wItems, 20, 3); put(b, L.wItems + 2, 0xFF)
  put(b, L.wNumKeyItems, 1); put(b, L.wKeyItems, 7); put(b, L.wKeyItems + 1, 0xFF)
  put(b, L.wNumBalls, 1); put(b, L.wBalls, 5, 9); put(b, L.wBalls + 2, 0xFF)
  -- box 3, one Pokemon
  local box = L.boxes[3]
  put(b, box, 1)
  put(b, box + 0x01, 7)
  put(b, box + 0x16, 7)
  put(b, box + 0x16 + 0x1F, 15)
  putName(b, box + 0x296, "ASH")
  putName(b, box + 0x372, "SQUIRT")
  seal(b, L)
  return pack(b)
 end
 -- ------------------------------------------------------------------
 -- What the cart holds comes back out
 -- ------------------------------------------------------------------
 for _, version in ipairs({ "gold", "silver", "crystal" }) do
  local save, err = Gen2Save.decode(build(version), version)
  check(save ~= nil, version .. ": a valid save decodes -- " .. tostring(err))
  if save then
    eq(save.player.name, "ASH", version .. ": player name")
    eq(save.rival.name, "GARY", version .. ": rival name")
    eq(save.player.id, 0x1234, version .. ": trainer id is big-endian")
    eq(save.player.money, 123456, version .. ": money is a 3-byte big-endian")
    eq(save.player.badges.ZEPHYR, true, version .. ": badges are keyed by name")
    eq(save.player.badges.PLAIN, true, version .. ": and the second bit too")
    eq(save.player.badges.HIVE, nil, version .. ": an unearned badge is absent")
    eq(#save.party, 1, version .. ": party size")
    local m = save.party[1]
    eq(m.species, 155, version .. ": species, uncrosswalked")
    eq(m.level, 42, version .. ": level")
    eq(m.maxHp, 100, version .. ": max hp")
    eq(m.stats.attack, 55, version .. ": computed stats come off the party tail")
    eq(#m.moves, 2, version .. ": empty move slots are dropped")
    eq(m.nickname, "FLAME", version .. ": nickname")
    eq(m.ot, "ASH", version .. ": OT name")
    eq(m.happiness, 200, version .. ": happiness")
    -- DVs are nibbles, and the HP DV is rebuilt from the other four's low bits
    eq(m.dvs.attack, 9, version .. ": attack DV is the high nibble")
    eq(m.dvs.defense, 15, version .. ": defense DV is the low nibble")
    eq(m.dvs.speed, 6, version .. ": speed DV")
    eq(m.dvs.special, 10, version .. ": special DV")
    eq(m.dvs.hp, 12, version .. ": HP DV is rebuilt, not stored")
    eq(#save.boxes, 14, version .. ": every box is present")
    eq(#save.boxes[3], 1, version .. ": box 3 holds one Pokemon")
    eq(save.boxes[3][1].species, 7, version .. ": the stored species, uncrosswalked")
    eq(save.boxes[3][1].nickname, "SQUIRT", version .. ": box nicknames follow the OTs")
    eq(save.boxes[3][1].ot, "ASH", version .. ": box OT")
    eq(save.boxes[3][1].hp, nil, version .. ": a box mon carries no computed stats")
  end
 end
 -- ------------------------------------------------------------------
 -- The engine is keyed by name, so the codec has to translate
 -- ------------------------------------------------------------------
 --
 -- The cart stores numbers. save.inventory holds POTION, mon.species is
 -- "TYPHLOSION", data.pokemon is indexed by that name. Without this the import
 -- looks perfect and the engine cannot read a byte of it.
 local CROSSWALK = {
  pokemon = { CYNDAQUIL = { index = 155 }, SQUIRTLE = { index = 7 } },
  moves   = { TACKLE = { index = 33 }, LEER = { index = 43 } },
  items   = { POTION = { index = 20 }, BICYCLE = { index = 7 },
              POKE_BALL = { index = 5 } },
  maps    = { GOLDENROD_CITY = { group = 21, map = 14 } },
 }
 do
  local save = assert(Gen2Save.decode(build("gold"), "gold", CROSSWALK))
  local m = save.party[1]
  eq(m.species, "CYNDAQUIL", "species is the engine's id, not the cart's number")
  eq(m.moves[1], "TACKLE", "and so are moves")
  eq(m.moves[2], "LEER", "both of them")
  eq(save.boxes[3][1].species, "SQUIRTLE", "boxes translate too")
  -- One flat bag. Nothing in src reads save.keyItems or save.balls; PackMenu
  -- buckets save.inventory by each item's own pocket.
  eq(save.keyItems, nil, "there is no separate key item table")
  eq(save.balls, nil, "nor a separate ball table")
  eq(save.inventory.POTION, 3, "the ITEM pocket lands in the bag")
  eq(save.inventory.BICYCLE, 1, "so does KEY_ITEM, which is why you can cycle")
  eq(save.inventory.POKE_BALL, 9, "and BALL, which is why you can throw one")
  -- Save.summary does `save.position.map or save.spawn`, so a save with no
  -- map key resumes at the spawn point with the old coordinates.
  eq(save.position.map, "GOLDENROD_CITY", "position names the map it is on")
  -- save.pokedex.caught[species] = true, keyed the same way.
  local dexKey = next(save.pokedex.caught)
  check(dexKey == nil or type(dexKey) == "string" or type(dexKey) == "number",
    "the dex is keyed by species id")
  -- Save.scrubEvents runs tonumber over the VALUE against Save.EVENT_BYTES,
  -- and tonumber(true) is nil, so a set of booleans is silently emptied.
  eq(type(save.events[0]), "number", "events are packed bytes, not booleans")
  local evCount = 0
  for _ in pairs(save.events) do evCount = evCount + 1 end
  eq(evCount, Gen2Save.EVENT_BYTES, "one entry per event byte")
  -- 0 is truthy in Lua, so a raw status byte makes healthy mons look ill.
  eq(m.status, "brn", "status is the engine's class string")
  eq(save.boxes[3][1].status, nil, "and nil when healthy, not 0")
 end
 -- Without a crosswalk the raw numbers survive rather than being dropped: an id
 -- this build cannot name is still the player's.
 do
  local save = assert(Gen2Save.decode(build("gold"), "gold"))
  eq(save.party[1].species, 155, "an unknown species keeps its cart number")
 end
 -- ------------------------------------------------------------------
 -- Export: what goes in comes back out, including what changed
 -- ------------------------------------------------------------------
 --
 -- Exporting a save onto the buffer it was decoded from proves nothing: every
 -- region encode does not write matches because it was copied. So this CHANGES
 -- things first, in each of the places export has to reach, and reads them back
 -- through a fresh decode.
 do
  local ITEMS = {
    POTION      = { index = 20, pocket = "ITEM" },
    BICYCLE     = { index = 7,  pocket = "KEY_ITEM" },
    POKE_BALL   = { index = 5,  pocket = "BALL" },
    TM_HEADBUTT = { index = 191, pocket = "TM_HM", tmNumber = 2 },
  }
  local data = {
    pokemon = CROSSWALK.pokemon, moves = CROSSWALK.moves,
    items = ITEMS, maps = CROSSWALK.maps,
  }
  local cart = build("gold")
  local save = assert(Gen2Save.decode(cart, "gold", data))
  save.inventory = { POTION = 7, BICYCLE = 1, POKE_BALL = 12, TM_HEADBUTT = 1 }
  save.currentBox = 5
  save.party[1].status, save.party[1].statusTurns = "slp", 3
  save.party[1].pokerus = 0x34
  save.party[1].caughtData = 0x1234
  save.events[9] = 0xA5
  local out = assert(Gen2Save.encode(save, "gold", cart, data))
  eq(#out, #cart, "the image keeps its size")
  local back = assert(Gen2Save.decode(out, "gold", data))
  -- The bag: encode used to leave it at whatever the template carried, so a
  -- potion bought in a session never reached the cartridge.
  eq(back.inventory.POTION, 7, "the ITEM pocket is written")
  eq(back.inventory.BICYCLE, 1, "and KEY_ITEM")
  eq(back.inventory.POKE_BALL, 12, "and BALL")
  eq(back.inventory.TM_HEADBUTT, 1, "and TM_HM, by its tmNumber")
  eq(back.currentBox, 5, "the open box is written")
  -- 0x1C-0x1E are the mon's, not the slot's: left to the template, reordering
  -- the party gives slot 1 the previous occupant's pokerus and caught data.
  eq(back.party[1].pokerus, 0x34, "pokerus rides the mon")
  eq(back.party[1].caughtData, 0x1234, "so does caught data")
  eq(back.party[1].status, "slp", "status survives as a class")
  eq(back.party[1].statusTurns, 3, "with its turn count")
  eq(back.events[9], 0xA5, "event bytes are written")
 end
 -- A save with no cartridge image behind it is refused, not invented.
 do
  local out, err = Gen2Save.encode({ player = { name = "A" } }, "gold", nil, {})
  eq(out, nil, "encode refuses a save with no lineage")
  check(type(err) == "string" and err:find("no cartridge image", 1, true) ~= nil,
    "and says why -- " .. tostring(err))
 end
 -- ------------------------------------------------------------------
 -- A save the real cartridge would open must not be refused
 -- ------------------------------------------------------------------
 --
 -- TryLoadSaveFile checks the primary, and on failure VerifyBackupChecksum and
 -- LoadBackupPlayerData. Refusing on the primary alone reports a save the game
 -- itself would load as corrupt, which is what #1832 was about.
 do
  local L = Gen2Save.layoutFor("crystal")
  check(L.backup ~= nil, "Crystal carries a backup layout")
  eq(Gen2Save.layoutFor("gold").backup, nil,
    "Gold and Silver split theirs across three sections, so they have none")
  local good = build("crystal")
  local at = L.sChecksum + 1
  local broken = good:sub(1, at - 1)
    .. string.char((good:byte(at) + 1) % 256) .. good:sub(at + 1)
  eq(Gen2Save.checksumValid(broken, L), false, "the primary is now corrupt")
  eq(Gen2Save.checksumValid(broken, L.backup), true, "the backup is not")
  local save, err = Gen2Save.decode(broken, "crystal")
  check(save ~= nil, "so the save still opens -- " .. tostring(err))
  if save then
    eq(save.player.name, "ASH", "and reads the same player out of the backup")
  end
 end
 -- ------------------------------------------------------------------
 -- Gold's table is not Crystal's
 -- ------------------------------------------------------------------
 do
  local goldBytes = build("gold")
  local wrong, err = Gen2Save.decode(goldBytes, "crystal")
  check(wrong == nil, "a Gold save read with Crystal's table is refused")
  check(type(err) == "string" and err:find("checksum", 1, true) ~= nil,
    "and refused by the guard, not by luck -- got: " .. tostring(err))
  check(Gen2Layout.goldSilver.wPartyMons ~= Gen2Layout.crystal.wPartyMons,
    "the two layouts really do disagree about where the party is")
 end
 -- ------------------------------------------------------------------
 -- Through the launcher's own entry point
 -- ------------------------------------------------------------------
 do
  local save, err = SaveConvert.importSav(build("gold"), "gold", "gold")
  check(save ~= nil, "importSav accepts a Gen 2 save now -- " .. tostring(err))
  if save then
    eq(save.player.name, "ASH", "and returns the decoded player")
    eq(save.generation, 2, "tagged as Gen 2")
    -- Everything the cart does not carry still has to be there.
    check(type(save.mail) == "table", "mail falls back to the new-game default")
    check(type(save.hallOfFame) == "table", "so does the hall of fame")
    check(type(save.phoneContacts) == "table", "and the phone book")
  end
  -- Export needs the cartridge image the save came from. Without one it is
  -- refused rather than built from nothing.
  local _, expErr = SaveConvert.exportSav({ meta = {} }, "gold")
  check(type(expErr) == "string" and expErr:find("no cartridge image", 1, true) ~= nil,
    "a save with no cartridge behind it is refused -- got: " .. tostring(expErr))
 end
 -- ------------------------------------------------------------------
 -- Real-save audit (fixture-gated)
 -- ------------------------------------------------------------------
 local fixture = os.getenv("POKEPORT_GEN2_SAV_FIXTURE")
 local fixtureVersion = os.getenv("POKEPORT_GEN2_SAV_VERSION") or "crystal"
 if not fixture then
  print("real-save audit skipped (set POKEPORT_GEN2_SAV_FIXTURE to a Gen 2 .sav, "
    .. "and POKEPORT_GEN2_SAV_VERSION to gold/silver/crystal)")
 else
  local f = io.open(fixture, "rb")
  local bytes = f and f:read("*a")
  if f then f:close() end
  check(bytes ~= nil, "the fixture is readable")
  if bytes then
    local save, err = Gen2Save.decode(bytes, fixtureVersion)
    check(save ~= nil, "a real cart save decodes -- " .. tostring(err))
    if save then
      check(#save.party >= 1 and #save.party <= 6, "party size is possible")
      check(#save.player.name > 0, "the player has a name")
      for i, mon in ipairs(save.party) do
        check(mon.species >= 1 and mon.species <= Gen2Save.NUM_SPECIES,
          ("party %d species is a real species (%d)"):format(i, mon.species))
        check(mon.level >= 1 and mon.level <= 100,
          ("party %d level is possible (%d)"):format(i, mon.level))
        check(mon.dvs.attack <= 15 and mon.dvs.special <= 15,
          ("party %d DVs are nibbles"):format(i))
      end
      for b, box in ipairs(save.boxes) do
        check(#box <= Gen2Save.BOX_CAPACITY, ("box %d holds at most 20"):format(b))
      end
      -- And back out. Without the item table the bag cannot be bucketed, so
      -- this asserts the refusal rather than a lossy write.
      local out, err = Gen2Save.encode(save, fixtureVersion, bytes, {})
      if out then
        eq(#out, #bytes, "the exported image keeps the cart's size, RTC and all")
        local back = assert(Gen2Save.decode(out, fixtureVersion))
        eq(back.player.name, save.player.name, "the player survives the round trip")
        eq(#back.party, #save.party, "and the party")
        local a, b2 = 0, 0
        for _, box in ipairs(save.boxes) do a = a + #box end
        for _, box in ipairs(back.boxes) do b2 = b2 + #box end
        eq(b2, a, "and every stored Pokemon")
      else
        check(err:find("pocket", 1, true) ~= nil,
          "or it refuses because the bag cannot be sorted -- " .. tostring(err))
      end
    end
  end
 end
 T.finish()
@@ -0,0 +1,127 @@
 -- A real Gen 2 cart save is 32786 bytes, and that must not be held against it
 -- (#1832).
 --   luajit tests/gen2_save_import_message_test.lua
 -- Also dofile'd by tests/run_tests.lua.
 --
 -- Gen 2 carts are MBC3+TIMER, so a real Gold/Silver/Crystal battery save
 -- carries an RTC footer past the 32768 bytes of SRAM. SaveFileIO.importToSlot
 -- judges anything that is not exactly SAVE_SIZE, and it used to judge it with
 -- pokered's main-data checksum whatever game it was for, so every real Gen 2
 -- save came back "save data checksum invalid" -- a perfectly good save
 -- reported as corrupt.
 --
 -- This is the size gate specifically. tests/gen2_save_import_test.lua covers
 -- the codec.
 package.path = "./?.lua;./?/init.lua;" .. package.path
 love = love or require("tests.love_stub")
 -- SaveData is stubbed so this stays about the gate: the real one wants a
 -- filesystem and a registry, and neither is the subject here.
 local written = {}
 package.loaded["src.core.SaveData"] = {
  load = function() return { meta = {} } end,
  activeSlot = function() return "slot1" end,
  buildMeta = function(_, m) return m or {} end,
  createSlot = function() return "slot1" end,
  writeSlot = function(_, _, save) written[#written + 1] = save return true end,
  setActiveSlot = function() return true end,
 }
 local T = require("tests.harness")
 local check, eq = T.check, T.eq
 local Gen2Save = require("src.save_convert.Gen2Save")
 local SaveConvert = require("src.save_convert.SaveConvert")
 local SaveFileIO = require("src.import.SaveFileIO")
 -- The size a real Gen 2 cart save actually is: 32768 of SRAM plus an 18-byte
 -- RTC footer. Verified against a real Gold cartridge in an emulator core,
 -- which reports the cart's backup size as exactly this.
 local GEN2_CART_SAVE_SIZE = 32786
 local function validSave(version, trailing)
  local L = Gen2Save.layoutFor(version)
  local b = {}
  for i = 0, Gen2Save.SAVE_SIZE - 1 do b[i] = 0 end
  b[L.wPlayerName] = 0x80        -- "A", so the save is not entirely blank
  b[L.wPlayerName + 1] = 0x50
  b[L.sCheckValue1] = 0x63
  b[L.sCheckValue2] = 0x7F
  local sum = 0
  for i = L.sGameData, L.sGameDataEnd - 1 do sum = (sum + b[i]) % 65536 end
  b[L.sChecksum] = sum % 256
  b[L.sChecksum + 1] = math.floor(sum / 256) % 256
  local out = {}
  for i = 0, Gen2Save.SAVE_SIZE - 1 do out[i + 1] = string.char(b[i]) end
  return table.concat(out) .. string.rep("\0", trailing or 0)
 end
 local function savFile(bytes)
  local path = os.tmpname()
  local f = assert(io.open(path, "wb"))
  f:write(bytes)
  f:close()
  return path
 end
 -- ------------------------------------------------------------------
 -- The report: a real-sized Gen 2 save imports
 -- ------------------------------------------------------------------
 for _, version in ipairs({ "gold", "silver", "crystal" }) do
  local trailing = GEN2_CART_SAVE_SIZE - Gen2Save.SAVE_SIZE
  local path = savFile(validSave(version, trailing))
  written = {}
  -- force is deliberately NOT passed: the footer is the normal shape of a Gen
  -- 2 cart save, so it must not raise the oversize confirmation either.
  local ok, err = SaveFileIO.importToSlot(path, version)
  check(ok == true,
    version .. ": a 32786-byte cart save imports -- " .. tostring(err))
  check(type(err) ~= "string" or err:find("checksum", 1, true) == nil,
    version .. ": and is never blamed on a checksum -- " .. tostring(err))
  eq(#written, 1, version .. ": the slot is written")
 end
 -- ------------------------------------------------------------------
 -- The checksum question is asked of the right generation
 -- ------------------------------------------------------------------
 do
  local gen2 = validSave("gold")
  eq(SaveConvert.mainChecksumValid(gen2, "gold"), true,
    "a Gen 2 save is valid under Gen 2's rule")
  eq(SaveConvert.mainChecksumValid(gen2), false,
    "and would read as invalid under Gen 1's, which is the whole bug")
  check(SaveConvert.isGen2Cart("crystal"), "Crystal is a Gen 2 cart")
  check(not SaveConvert.isGen2Cart("red"), "Red is not")
 end
 -- ------------------------------------------------------------------
 -- Gen 1 keeps its own diagnosis
 -- ------------------------------------------------------------------
 do
  local path = savFile(string.rep("\0", GEN2_CART_SAVE_SIZE))
  local ok, err = SaveFileIO.importToSlot(path, "red", true)
  check(ok == false, "red: a corrupt oversize save is still refused")
  check(type(err) == "string" and err:find("checksum", 1, true) ~= nil,
    "red: still diagnosed by pokered's checksum -- got: " .. tostring(err))
 end
 -- ------------------------------------------------------------------
 -- Export needs the cartridge image behind the save
 -- ------------------------------------------------------------------
 -- Export goes through the codec now, but only for a save that came from a
 -- cartridge: the regions it does not model are the ones the real game trusts
 -- on CONTINUE.
 for _, version in ipairs({ "gold", "silver", "crystal" }) do
  eq(SaveConvert.exportSupported(version), true, version .. ": export is supported")
  local out, why = SaveConvert.exportSav({ meta = {}, player = { name = "A" } }, version)
  eq(out, nil, version .. ": a save with no cartridge behind it is refused")
  check(type(why) == "string" and why:find("no cartridge image", 1, true) ~= nil,
    version .. ": and the reason is the missing image -- " .. tostring(why))
 end
 T.finish()
@@ -85,4 +85,31 @@ do
    "MOD INDEX panel does not force the full MODS list")
 end
 do
  local calls = 0
  local old = LauncherMods.list
  LauncherMods.list = function()
    calls = calls + 1
    return {
      { id = "scoped", name = "Scoped", targetsHere = true },
      { id = "other", name = "Other", targetsHere = false },
    }
  end
  local imp = setmetatable({
    modScope = "red",
    modStraysChecked = true,
    activeCart = {},
  }, RomImporter)
  imp:_refreshMods()
  local listed = calls
  check(listed >= 1, "refresh lists installed mods")
  eq(imp:_cartCaptureCount("red"), 1,
    "capture count is the targeting subset")
  eq(calls, listed,
    "Save as cart does not re-list after the panel already has the rows")
  eq(imp:_cartCaptureCount("red"), 1, "a second count is the same answer")
  eq(calls, listed, "and still does not re-list")
  LauncherMods.list = old
 end
 T.finish("launcher_navigation_perf")
@@ -226,6 +226,8 @@ do
    -- The double has to answer it; "yes" is what keeps this case about the
    -- cache-name contract below and nothing else.
    importSupported = function() return true end,
    -- Red is not a Gen 2 cart, which is what this case uses.
    isGen2Cart = function() return false end,
    importSav = function(_, version, gameVersion)
      seen.import = { version = version, gameVersion = gameVersion }
      return nil, "stub"
@@ -62,20 +62,29 @@ write(goldPath, SaveSerializer.encode({
 local out = run(("luajit tools/save_convert/convert.lua export %q %q")
  :format(goldPath, outPath))
-check(out:find("Gen 2 cart save", 1, true) ~= nil,
+-- Gen 2 exports through Gen2Save now, but only for a save that carries the
-  "exporting a Gold save.lua is refused by name: " .. (out:gsub("%s+$", "")))
+-- cartridge image it came from. A slot built in the launcher has none.
 check(out:find("no cartridge image", 1, true) ~= nil,
  "exporting a Gold slot with no cartridge behind it is refused, and says why: "
    .. (out:gsub("%s+$", "")))
 check(not exists(outPath),
  "and no 32768-byte file that looks like a Red battery is written")
-- The same gate on the way in, when the caller names the game.
+-- The way IN is no longer a gate: Gen 2 imports through
 -- src/save_convert/Gen2Save.lua now.  What this pins is that the bytes reach
 -- that codec and are judged by ITS rules -- an all-zero image has neither of
 -- Gen 2's check values, so it is refused for being blank rather than for
 -- being Gold.
 local savPath = tmp("in.sav")
 local outPath2 = tmp("in.lua")
 os.remove(outPath2)
 write(savPath, string.rep("\0", 32768))
 out = run(("luajit tools/save_convert/convert.lua import %q %q gold")
  :format(savPath, outPath2))
-check(out:find("Gen 2 cart save", 1, true) ~= nil,
+check(out:find("not supported yet", 1, true) == nil,
-  "importing for a Gen 2 game is refused too")
+  "importing for a Gen 2 game is no longer refused by version: " .. (out:gsub("%s+$", "")))
 check(out:find("checksum", 1, true) ~= nil,
  "a blank image is refused on Gen 2's own check values: " .. (out:gsub("%s+$", "")))
 check(not exists(outPath2), "and writes nothing")
 -- Gen 1 keeps working: a Red-shaped save is never caught by the Gen 2 gate.
@@ -66,8 +66,8 @@ check(files["saves/gold/" .. tostring(slotId) .. ".lua"] ~= nil,
 local ok, res = SaveFileIO.exportActiveSlot("gold")
 eq(ok, false, "Export on a Gold slot is refused, not crashed")
-check(type(res) == "string" and res:find("not supported yet", 1, true),
+check(type(res) == "string" and res:find("no cartridge image", 1, true),
-      "the refusal is the plain launcher message: " .. tostring(res))
+      "the refusal names the missing cartridge image: " .. tostring(res))
 check(not tostring(res):find("GenSave", 1, true)
      and not tostring(res):find("attempt to index", 1, true),
      "no codec traceback leaks into the notice line")
@@ -77,12 +77,17 @@ for path in pairs(files) do
 end
 eq(exported, false, "no export file is written for a Gold slot")
-- The import direction through the same seam: a 32 KB image aimed at Gold
+-- The import direction no longer matches the export one. Gold imports through
-- must be refused by version, before any Gen 1 decoding is attempted.
+-- Gen2Save now, so a 32 KB image aimed at Gold is decoded rather than turned
 -- away by version. An all-zero image still fails, because Gen 2's guards are
 -- two check values and a sum and a blank image has none of them: refused for
 -- what it is, not for which game it is for.
 local iok, ierr = SaveConvert.importSav(string.rep("\0", 32768), "gold", "gold")
-eq(iok, nil, "importing a cart .sav for Gold is refused")
+eq(iok, nil, "a blank cart .sav for Gold is still refused")
-check(type(ierr) == "string" and ierr:find("not supported yet", 1, true),
+check(type(ierr) == "string" and ierr:find("not supported yet", 1, true) == nil,
-      "the import refusal is the plain launcher message: " .. tostring(ierr))
+      "and no longer refused by version: " .. tostring(ierr))
 check(type(ierr) == "string" and ierr:find("checksum", 1, true) ~= nil,
      "it is Gen 2's own guards that turn it away: " .. tostring(ierr))
 -- Gen 1 versions still pass the gate: red reaches the codec proper and
 -- fails on its own terms (an all-zero image is not a table), never on the
@@ -1,96 +0,0 @@
 -- A Gen 2 cart save must be refused as a Gen 2 cart save, not as a corrupt
 -- Gen 1 one (#1832).
 --   luajit tests/gen2_save_import_message_test.lua
 -- Also dofile'd by tests/run_tests.lua.
 --
 -- SaveFileIO.importToSlot judges anything that is not exactly SAVE_SIZE with
 -- SaveConvert.mainChecksumValid, which is pokered's main-data checksum.  Gen 2
 -- carts are MBC3+TIMER, so a real Gold/Silver/Crystal battery save carries an
 -- RTC footer and is 32786 bytes: it misses the size test, is then measured
 -- against a checksum rule written for a different generation, and the launcher
 -- tells the player their save is corrupt.  It is not -- there is simply no Gen
 -- 2 codec yet, which is a different sentence and an actionable one.
 package.path = "./?.lua;./?/init.lua;" .. package.path
 love = love or require("tests.love_stub")
 local S = require("tests.harness").suite("gen2 save import message")
 local check = S.check
 local SaveConvert = require("src.save_convert.SaveConvert")
 local SaveFileIO = require("src.import.SaveFileIO")
 -- The size a real Gen 2 cart save actually is: 32768 bytes of SRAM plus the
 -- 18-byte RTC footer an MBC3+TIMER cart writes.
 local GEN2_CART_SAVE_SIZE = 32786
 local function blob(n) return string.rep("\0", n) end
 -- readSource only takes a raw string when it is EXACTLY 32768 bytes; anything
 -- else is treated as a picker path (its own comment says so).  A real Gen 2
 -- cart save is 32786, so it can only ever reach importToSlot as a FILE -- which
 -- is exactly how the player in #1832 supplied theirs.  Write one and hand over
 -- the path, so this exercises the route the report came from.
 local function savFile(n)
  local path = os.tmpname()
  local f = assert(io.open(path, "wb"))
  f:write(blob(n))
  f:close()
  return path
 end
 -- ------------------------------------------------------------------
 -- The report: a real Gen 2 save is not "checksum invalid"
 -- ------------------------------------------------------------------
 for _, version in ipairs({ "gold", "silver", "crystal" }) do
  local ok, err = SaveFileIO.importToSlot(savFile(GEN2_CART_SAVE_SIZE), version, true)
  check(ok == false, version .. ": a Gen 2 cart save is still refused")
  check(type(err) == "string" and err:find("Gen 2 cart save", 1, true) ~= nil,
    version .. ": refused AS a Gen 2 save -- got: " .. tostring(err))
  check(type(err) == "string" and err:find("checksum", 1, true) == nil,
    version .. ": never blamed on a checksum it was never measured by -- got: "
      .. tostring(err))
 end
 -- ------------------------------------------------------------------
 -- The predicate both callers share
 -- ------------------------------------------------------------------
 for _, version in ipairs({ "red", "blue", "yellow" }) do
  check(SaveConvert.importSupported(version) == true,
    version .. ": Gen 1 import is unaffected")
  check(SaveConvert.exportSupported(version) == true,
    version .. ": Gen 1 export is unaffected")
 end
 for _, version in ipairs({ "gold", "silver", "crystal" }) do
  local impOk, impWhy = SaveConvert.importSupported(version)
  local expOk, expWhy = SaveConvert.exportSupported(version)
  check(impOk == false and expOk == false, version .. ": both directions say no")
  -- One sentence per direction, wherever it is asked from: the early gate in
  -- SaveFileIO and the late one inside importSav must not describe the same
  -- game two different ways.
  local _, lateWhy = SaveConvert.importSav(blob(32768), version, version)
  check(impWhy == lateWhy,
    version .. ": the early gate and importSav answer identically")
  check(expWhy:find("exporting", 1, true) ~= nil,
    version .. ": the export sentence is about exporting")
 end
 -- ------------------------------------------------------------------
 -- Gen 1 keeps its own diagnosis
 -- ------------------------------------------------------------------
 --
 -- A Gen 1 save that really is the wrong size AND fails pokered's checksum must
 -- still say so: this fix moves the generation check in front of that test, it
 -- does not remove it.
 do
  local ok, err = SaveFileIO.importToSlot(savFile(GEN2_CART_SAVE_SIZE), "red", true)
  check(ok == false, "red: a corrupt oversize save is still refused")
  check(type(err) == "string" and err:find("checksum", 1, true) ~= nil,
    "red: still diagnosed by pokered's checksum -- got: " .. tostring(err))
 end
 S.finish()
@@ -0,0 +1,78 @@
 -- A sandboxed mod can take a Pokémon's level off the screens that print it
 -- (pokemon.level_visible): the readout goes, the layout does not, and a
 -- build with no mod wrapping the hook prints exactly what it always did.
 --
 -- The predicate is tested rather than the pixels: every Gen 1 level readout
 -- goes through LevelDisplay.visible, and the four call sites are the same
 -- one-line guard. What matters here is the contract -- default true, false
 -- suppresses, the surface is named, and no-mod costs nothing.
 package.path = "./?.lua;./?/init.lua;" .. package.path
 love = love or require("tests.love_stub")
 local T = require("tests.modkit")
 local LevelDisplay = require("src.ui.LevelDisplay")
 local FIXTURE = {
  ["mods/level_probe/manifest.json"] = [[{
    "id": "level_probe",
    "name": "Level Probe",
    "version": "1.0.0",
    "entry": "main.lua",
    "api": 2
  }]],
  ["mods/level_probe/main.lua"] = [[
    local mod = ...
    mod.exports.answer = nil
    mod.exports.seen = nil
    mod.hooks:wrap("pokemon.level_visible", function(next, mon, ctx)
      mod.exports.seen = { mon = mon, where = ctx and ctx.where,
                           game = ctx and ctx.game }
      if mod.exports.answer == nil then return next(mon, ctx) end
      return mod.exports.answer
    end)
  ]],
 }
 local MON = { species = "RATTATA", level = 42, moves = {} }
 local GAME = { save = {} }
 -- ------- no mod: the level is always printed
 local vanilla = T.sdk.loadNone({})
 T.eq(LevelDisplay.visible(MON, "battle.enemy", GAME), true,
  "no mod: the enemy healthbox prints a level")
 T.eq(LevelDisplay.visible(MON, "party", GAME), true,
  "no mod: the party rows print a level")
 T.eq(LevelDisplay.visible(nil, "summary", nil), true,
  "no mod: even a nil mon answers true rather than throwing")
 vanilla.release()
 -- ------- a mod hides it
 local run = T.sdk.loadMods({ "mods/level_probe" }, { fs = T.sdk.memfs(FIXTURE) })
 T.eq(#run.errors, 0, "the level probe loads clean (" .. tostring(run.errors[1]) .. ")")
 local probe = run.loader.exports.level_probe
 probe.answer = false
 T.eq(LevelDisplay.visible(MON, "battle.enemy", GAME), false,
  "hidden: the enemy healthbox prints no level")
 T.eq(probe.seen and probe.seen.where, "battle.enemy",
  "the hook is told which surface asked")
 T.check(probe.seen and probe.seen.mon == MON, "and which Pokémon")
 T.check(probe.seen and probe.seen.game == GAME, "and the game")
 -- the surface is what lets a mode hide an opponent's level and keep its own
 probe.answer = nil
 T.eq(LevelDisplay.visible(MON, "party", GAME), true,
  "falling through prints, as today")
 T.eq(probe.seen and probe.seen.where, "party", "and still names the surface")
 -- only an explicit false suppresses: a mod returning nothing must not blank
 -- a screen by accident
 probe.answer = true
 T.eq(LevelDisplay.visible(MON, "summary", GAME), true,
  "an explicit true prints")
 run.release()
 T.finish("pokemon level visible")
@@ -3640,7 +3640,6 @@ runSuites(orderedGlob(
  -- name resolution, and the .sav converter refusing a Gen 2 save table.
  "tests/gen2_sound_alias_test.lua",
  "tests/gen2_save_convert_cli_test.lua",
  "tests/gen2_save_import_message_test.lua",
  -- The wall radios (`special MapRadio`).  gen2_save_export_test cannot share a
  -- process (LEAKS_SAVE_SLOT_STATE above); tests/run_gen2.lua runs it alone.
  "tests/gen2_map_radio_test.lua",
@@ -0,0 +1,185 @@
 #!/usr/bin/env python3
 """Emit src/save_convert/Gen2Layout.lua from a pret build's symbol files.
 Gen 2 saves a contiguous WRAM block into SRAM bank 1, so every field's file
 offset inside the 32768-byte battery image is
    sPlayerData_offset + (wField - wPlayerData)
 with sPlayerData_offset = sPlayerData - $A000 + $2000.  That relation is
 asserted below against sPokemonData, which appears on both sides.
 Nothing here is transcribed.  Build pret/pokegold and pret/pokecrystal, then:
    python3 tools/gen2_sram_offsets.py \
        --gold  path/to/pokegold.sym \
        --crystal path/to/pokecrystal.sym \
        > src/save_convert/Gen2Layout.lua
 Gold and Silver share a layout (pokesilver.sym agrees byte-exact); Crystal does
 not, and that is the whole reason this file emits two tables.
 """
 import argparse, re, sys
 FIELDS = [
    "wPlayerName", "wPlayerID", "wMoney", "wCoins", "wBadges", "wKantoBadges",
    "wRivalName", "wMomsName", "wPartyCount", "wPartySpecies", "wPartyMons",
    "wPartyMonNicknames", "wPartyMonOTs", "wNumItems", "wItems", "wNumKeyItems",
    "wKeyItems", "wNumBalls", "wBalls", "wTMsHMs", "wPokedexCaught",
    "wPokedexSeen", "wCurBox", "wBoxNames", "wMapGroup", "wMapNumber",
    "wXCoord", "wYCoord", "wEventFlags", "wPlayerState",
    "wGameTimeHours", "wGameTimeMinutes",
 ]
 GUARDS = ["sCheckValue1", "sCheckValue2", "sChecksum", "sGameData", "sGameDataEnd"]
 # The 14 archived PC boxes. Emitted as real per-box offsets, never a stride:
 # boxes 1-7 live in SRAM bank 2 and 8-14 in bank 3, so the step from box 7 to
 # box 8 is 0x620 rather than the 0x450 every other pair uses. Computing them
 # from a uniform stride puts boxes 8-14 in the wrong place, and a real save
 # then reports box counts like 243 and 196.
 BOX_COUNT = 14
 def load(path):
    out = {}
    for line in open(path):
        m = re.match(r"^(\w\w):(\w{4})\s+(\S+)\s*$", line)
        if m:
            out.setdefault(m.group(3), (int(m.group(1), 16), int(m.group(2), 16)))
    return out
 # The backup copy the game falls back to when the primary checksum fails
 # (TryLoadSaveFile -> VerifyBackupChecksum). Crystal's is contiguous and laid
 # out exactly like the primary, so it is the same table shifted. Gold and
 # Silver split theirs across three sections and are not derivable this way,
 # which is why only Crystal gets one.
 def backup_table(sym, rows, label):
    need = ["sBackupGameData", "sBackupGameDataEnd", "sBackupCheckValue1",
            "sBackupCheckValue2", "sBackupChecksum", "sGameData"]
    if any(n not in sym for n in need):
        return None
    off = lambda n: sym[n][0] * 0x2000 + (sym[n][1] - 0xA000)
    # File offsets, not raw addresses: the backup lives in SRAM bank 0 and the
    # primary in bank 1, so an address-only delta is off by a bank.
    delta = off("sBackupGameData") - off("sGameData")
    guards = {"sCheckValue1": off("sBackupCheckValue1"),
              "sCheckValue2": off("sBackupCheckValue2"),
              "sChecksum": off("sBackupChecksum"),
              "sGameData": off("sBackupGameData"),
              "sGameDataEnd": off("sBackupGameDataEnd")}
    out = []
    for name, value in rows:
        if name in guards:
            out.append((name, guards[name]))
        else:
            out.append((name, value + delta))
    return out
 def table(sym, label):
    need = ["sPlayerData", "wPlayerData", "sPokemonData", "wPokemonData"] + GUARDS
    missing = [n for n in need if n not in sym]
    if missing:
        sys.exit(f"{label}: symbol file is missing {missing}")
    base = sym["sPlayerData"][1] - 0xA000 + 0x2000
    anchor = sym["wPlayerData"][1]
    # The block relation, asserted rather than assumed.
    if sym["sPokemonData"][1] - sym["sPlayerData"][1] != \
       sym["wPokemonData"][1] - sym["wPlayerData"][1]:
        sys.exit(f"{label}: the WRAM block is not copied contiguously; "
                 "the offset relation this generator rests on does not hold")
    lo, hi = sym["sGameData"][1], sym["sGameDataEnd"][1]
    rows, skipped = [], []
    for g in GUARDS:
        rows.append((g, sym[g][1] - 0xA000 + 0x2000))
    for f in FIELDS:
        w = sym.get(f)
        if not w:
            skipped.append(f + " (absent)")
            continue
        # Only fields INSIDE the saved block are addressable this way. Crystal's
        # wPlayerGender sits before wPlayerData and belongs to sCrystalData, and
        # the naive subtraction gives a confident wrong answer for it.
        if not (lo <= w[1] - anchor + sym["sPlayerData"][1] < hi):
            skipped.append(f + " (outside sGameData..sGameDataEnd)")
            continue
        rows.append((f, base + (w[1] - anchor)))
    boxes = []
    for i in range(1, BOX_COUNT + 1):
        b = sym.get("sBox%d" % i)
        if not b:
            sys.exit("%s: sBox%d is missing" % (label, i))
        # General SRAM form, which the bank-1 arithmetic above is a case of:
        # file offset = bank * 0x2000 + (addr - $A000).
        boxes.append(b[0] * 0x2000 + (b[1] - 0xA000))
    return rows, skipped, boxes
 # The cart's own text table, so a name with an apostrophe, an accent or the PK
 # glyph in it survives the round trip. Hand-keeping this list is how a player
 # called "Mattia<PK>" comes back as "Mattia?".
 CHARMAP_RE = re.compile(r'^\s*charmap\s+"(.+?)",\s*\$([0-9a-fA-F]{2})\s*(?:;.*)?$')
 def emit_charmap(path):
    rows = {}
    for line in open(path, encoding="utf-8"):
        m = CHARMAP_RE.match(line)
        if not m:
            continue
        glyph, code = m.group(1), int(m.group(2), 16)
        # Control tokens are not text; the name fields never contain them.
        if glyph.startswith("<") and glyph.endswith(">"):
            inner = glyph[1:-1]
            if inner in ("PK", "MN", "PO", "KE"):
                rows.setdefault(code, inner)
            continue
        rows.setdefault(code, glyph)
    print("Gen2Layout.charmap = {")
    for code in sorted(rows):
        glyph = rows[code].replace("\\", "\\\\").replace('"', '\\"')
        print(f'  [0x{code:02X}] = "{glyph}",')
    print("}")
    print()
 def main():
    ap = argparse.ArgumentParser()
    ap.add_argument("--gold", required=True)
    ap.add_argument("--crystal", required=True)
    ap.add_argument("--charmap", required=False,
                    help="path to pokegold constants/charmap.asm; emits the "
                         "text table too when given")
    a = ap.parse_args()
    print("-- GENERATED by tools/gen2_sram_offsets.py. Do not edit by hand.")
    print("-- Regenerate from a pret/pokegold + pret/pokecrystal build; see that")
    print("-- script's header for the derivation and the assertion behind it.")
    print("local Gen2Layout = {}\n")
    for key, path in (("goldSilver", a.gold), ("crystal", a.crystal)):
        sym = load(path)
        rows, skipped, boxes = table(sym, key)
        backup = backup_table(sym, rows, key)
        print(f"Gen2Layout.{key} = {{")
        for n, off in rows:
            print(f"  {n} = 0x{off:04X},")
        print("  -- The 14 archived boxes, listed rather than strided (see BOX_COUNT).")
        print("  boxes = { " + ", ".join("0x%04X" % b for b in boxes) + " },")
        if backup:
            print("  -- The backup copy the game falls back to when the primary")
            print("  -- checksum fails. Same shape, shifted.")
            print("  backup = {")
            for n, off in backup:
                print(f"    {n} = 0x{off:04X},")
            print("    boxes = { " + ", ".join("0x%04X" % b for b in boxes) + " },")
            print("  },")
        print("}")
        for s2 in skipped:
            print(f"-- not addressable via the block: {s2}")
        print()
    if a.charmap:
        emit_charmap(a.charmap)
    print("return Gen2Layout")
 main()