Dolphin Bootable ISO working!

src/duskdolphin/asset/assetdolphindvd.c

@@ -9,49 +9,86 @@
 #include "asset/asset.h"
 #include "util/string.h"
 #include "util/memory.h"
-#include "util/endian.h"
+
+#define ISO_SECTOR_SIZE   2048u
+#define ISO_PVD_SECTOR    16u
 
 errorret_t assetInitDolphinDVD(void) {
   DVD_Init();
   DVD_Mount();
 
-  // Read disc header to find FST location
-  u8 *hdr = (u8 *)assetDolphinDVDRead(0, 0x440);
-  if(!hdr) errorThrow("Failed to read DVD disc header.");
-  u32 fstOff  = assetDolphinDVDReadBigEndian32(hdr + 0x424);
-  u32 fstSize = assetDolphinDVDReadBigEndian32(hdr + 0x428);
-  memoryFree(hdr);
+  // ISO 9660 Primary Volume Descriptor is at sector 16.
+  u8 *pvd = (u8 *)assetDolphinDVDRead(
+    (s64)ISO_PVD_SECTOR * ISO_SECTOR_SIZE, ISO_SECTOR_SIZE
+  );
+  if(!pvd) errorThrow("Failed to read ISO 9660 PVD.");
 
-  // Read the FST
-  u8 *fst = (u8 *)assetDolphinDVDRead((s64)fstOff, fstSize);
-  if(!fst) errorThrow("Failed to read DVD FST.");
-
-  // Root entry (index 0) bytes 8-11 = total entry count
-  u32 numEntries = assetDolphinDVDReadBigEndian32(fst + 8);
-  u8 *strTable   = fst + numEntries * 12u;
-
-  u32 fileOff = 0, fileLen = 0;
-  for(u32 i = 1; i < numEntries; i++) {
-    u8 *e = fst + i * 12u;
-    if(e[0] != 0) continue;
-
-    u32 nameOff = ((u32)e[1] << 16) | ((u32)e[2] << 8) | (u32)e[3];
-    const char_t *name = (const char_t *)(strTable + nameOff);
-    if(stringCompareInsensitive(name, ASSET_FILE_NAME) == 0) {
-      fileOff = assetDolphinDVDReadBigEndian32(e + 4);
-      fileLen = assetDolphinDVDReadBigEndian32(e + 8);
-      break;
-    }
+  // Sanity-check: type=1, identifier="CD001"
+  if(pvd[0] != 1 || pvd[1] != 'C' || pvd[2] != 'D' ||
+     pvd[3] != '0' || pvd[4] != '0' || pvd[5] != '1') {
+    memoryFree(pvd);
+    errorThrow("Not a valid ISO 9660 disc.");
   }
-  memoryFree(fst);
 
-  if(!fileOff) errorThrow("Failed to find asset file on DVD.");
+  // Root Directory Record starts at PVD+156.
+  // ISO 9660 stores multi-byte fields in both byte orders; use the BE copies
+  // (offset +6 for LBA, +14 for size) since the GameCube is big-endian.
+  u32 rootLBA  = assetDolphinDVDReadBigEndian32(pvd + 156 + 6);
+  u32 rootSize = assetDolphinDVDReadBigEndian32(pvd + 156 + 14);
+  memoryFree(pvd);
 
-  u8 *data = (u8 *)assetDolphinDVDRead((s64)fileOff, fileLen);
-  if(!data) errorThrow("Failed to read asset file from DVD.");
+  u8 *dir = (u8 *)assetDolphinDVDRead(
+    (s64)rootLBA * ISO_SECTOR_SIZE, rootSize
+  );
+  if(!dir) errorThrow("Failed to read ISO 9660 root directory.");
+
+  // Scan directory records for dusk.dsk.
+  // ISO 9660 level-1 names are uppercase with a ";1" version suffix, e.g.
+  // "DUSK.DSK;1".  We strip the suffix before comparing case-insensitively.
+  u32 fileLBA = 0, fileSize = 0;
+  u32 pos = 0;
+  while(pos < rootSize) {
+    u8 recLen = dir[pos];
+    if(recLen == 0) {
+      // Sector padding — skip to the start of the next sector.
+      pos = (pos + (ISO_SECTOR_SIZE - 1u)) & ~(ISO_SECTOR_SIZE - 1u);
+      continue;
+    }
+
+    u8 flags   = dir[pos + 25];
+    u8 nameLen = dir[pos + 32];
+
+    if(!(flags & 0x02) && nameLen > 1) { // skip directories and "." / ".."
+      const char_t *isoName = (const char_t *)(dir + pos + 33);
+
+      // Build a null-terminated copy of the base name (strip ";N" version).
+      char_t baseName[32];
+      u8 baseLen = 0;
+      while(baseLen < nameLen && isoName[baseLen] != ';' && baseLen < 31) {
+        baseName[baseLen] = isoName[baseLen];
+        baseLen++;
+      }
+      baseName[baseLen] = '\0';
+
+      if(stringCompareInsensitive(baseName, ASSET_FILE_NAME) == 0) {
+        fileLBA  = assetDolphinDVDReadBigEndian32(dir + pos + 6);
+        fileSize = assetDolphinDVDReadBigEndian32(dir + pos + 14);
+        break;
+      }
+    }
+    pos += recLen;
+  }
+  memoryFree(dir);
+
+  if(!fileLBA) errorThrow("Failed to find asset file on ISO.");
+
+  u8 *data = (u8 *)assetDolphinDVDRead(
+    (s64)fileLBA * ISO_SECTOR_SIZE, fileSize
+  );
+  if(!data) errorThrow("Failed to read asset file from ISO.");
 
   zip_error_t zerr;
-  zip_source_t *src = zip_source_buffer_create(data, fileLen, 1, &zerr);
+  zip_source_t *src = zip_source_buffer_create(data, fileSize, 1, &zerr);
   if(!src) {
     memoryFree(data);
     errorThrow("Failed to create zip source from DVD buffer.");