2 files changed, 112 insertions, 89 deletions

diff --git a/cgpt/cgpt_common.c b/cgpt/cgpt_common.c
index 2c21cdc2..29fe524a 100644
--- a/cgpt/cgpt_common.c
+++ b/cgpt/cgpt_common.c
@@ -184,7 +184,11 @@ static int GptLoad(struct drive *drive, uint32_t sector_bytes) {
       return -1;
     }
   } else {
-    Warning("Primary GPT header is invalid\n");
+    Warning("Primary GPT header is %s\n",
+      memcmp(primary_header->signature, GPT_HEADER_SIGNATURE_IGNORED,
+             GPT_HEADER_SIGNATURE_SIZE) ? "invalid" : "being ignored");
+    drive->gpt.primary_entries = calloc(MAX_NUMBER_OF_ENTRIES,
+                                        sizeof(GptEntry));
   }
   GptHeader* secondary_header = (GptHeader*)drive->gpt.secondary_header;
   if (CheckHeader(secondary_header, 1, drive->gpt.streaming_drive_sectors,
@@ -198,41 +202,48 @@ static int GptLoad(struct drive *drive, uint32_t sector_bytes) {
       return -1;
     }
   } else {
-    Warning("Secondary GPT header is invalid\n");
+    Warning("Secondary GPT header is %s\n",
+      memcmp(primary_header->signature, GPT_HEADER_SIGNATURE_IGNORED,
+             GPT_HEADER_SIGNATURE_SIZE) ? "invalid" : "being ignored");
+    drive->gpt.secondary_entries = calloc(MAX_NUMBER_OF_ENTRIES,
+                                          sizeof(GptEntry));
   }
   return 0;
 }
 
 static int GptSave(struct drive *drive) {
   int errors = 0;
-  if (drive->gpt.modified & GPT_MODIFIED_HEADER1) {
-    if (CGPT_OK != Save(drive, drive->gpt.primary_header,
-                        GPT_PMBR_SECTORS,
-                        drive->gpt.sector_bytes, GPT_HEADER_SECTORS)) {
-      errors++;
-      Error("Cannot write primary header: %s\n", strerror(errno));
+
+  if (!(drive->gpt.ignored & MASK_PRIMARY)) {
+    if (drive->gpt.modified & GPT_MODIFIED_HEADER1) {
+      if (CGPT_OK != Save(drive, drive->gpt.primary_header,
+                          GPT_PMBR_SECTORS,
+                          drive->gpt.sector_bytes, GPT_HEADER_SECTORS)) {
+        errors++;
+        Error("Cannot write primary header: %s\n", strerror(errno));
+      }
     }
-  }
-  GptHeader* primary_header = (GptHeader*)drive->gpt.primary_header;
-  if (drive->gpt.modified & GPT_MODIFIED_ENTRIES1) {
-    if (CGPT_OK != Save(drive, drive->gpt.primary_entries,
-                        primary_header->entries_lba,
-                        drive->gpt.sector_bytes,
-                        CalculateEntriesSectors(primary_header))) {
-      errors++;
-      Error("Cannot write primary entries: %s\n", strerror(errno));
+    GptHeader* primary_header = (GptHeader*)drive->gpt.primary_header;
+    if (drive->gpt.modified & GPT_MODIFIED_ENTRIES1) {
+      if (CGPT_OK != Save(drive, drive->gpt.primary_entries,
+                          primary_header->entries_lba,
+                          drive->gpt.sector_bytes,
+                          CalculateEntriesSectors(primary_header))) {
+        errors++;
+        Error("Cannot write primary entries: %s\n", strerror(errno));
+      }
     }
-  }
 
-  // Sync primary GPT before touching secondary so one is always valid.
-  if (drive->gpt.modified & (GPT_MODIFIED_HEADER1 | GPT_MODIFIED_ENTRIES1))
-    if (fsync(drive->fd) < 0 && errno == EIO) {
-      errors++;
-      Error("I/O error when trying to write primary GPT\n");
-    }
+    // Sync primary GPT before touching secondary so one is always valid.
+    if (drive->gpt.modified & (GPT_MODIFIED_HEADER1 | GPT_MODIFIED_ENTRIES1))
+      if (fsync(drive->fd) < 0 && errno == EIO) {
+        errors++;
+        Error("I/O error when trying to write primary GPT\n");
+      }
+  }
 
   // Only start writing secondary GPT if primary was written correctly.
-  if (!errors) {
+  if (!errors && !(drive->gpt.ignored & MASK_SECONDARY)) {
     if (drive->gpt.modified & GPT_MODIFIED_HEADER2) {
       if(CGPT_OK != Save(drive, drive->gpt.secondary_header,
                          drive->gpt.gpt_drive_sectors - GPT_PMBR_SECTORS,
diff --git a/cgpt/cgpt_show.c b/cgpt/cgpt_show.c
index 143b5fa1..638655bd 100644
--- a/cgpt/cgpt_show.c
+++ b/cgpt/cgpt_show.c
@@ -250,79 +250,91 @@ static int GptShow(struct drive *drive, CgptShowParams *params) {
     PMBRToStr(&drive->pmbr, buf, sizeof(buf)); // will exit if buf is too small
     printf(GPT_FMT, 0, GPT_PMBR_SECTORS, "", buf);
 
-    if (drive->gpt.valid_headers & MASK_PRIMARY) {
+    if (drive->gpt.ignored & MASK_PRIMARY) {
       printf(GPT_FMT, (int)GPT_PMBR_SECTORS,
-             (int)GPT_HEADER_SECTORS, "", "Pri GPT header");
+             (int)GPT_HEADER_SECTORS, "IGNORED", "Pri GPT header");
     } else {
-      printf(GPT_FMT, (int)GPT_PMBR_SECTORS,
-             (int)GPT_HEADER_SECTORS, "INVALID", "Pri GPT header");
-    }
-
-    if (params->debug ||
-        ((drive->gpt.valid_headers & MASK_PRIMARY) && params->verbose)) {
-      GptHeader *header;
-      char indent[64];
+      if (drive->gpt.valid_headers & MASK_PRIMARY) {
+        printf(GPT_FMT, (int)GPT_PMBR_SECTORS,
+               (int)GPT_HEADER_SECTORS, "", "Pri GPT header");
+      } else {
+        printf(GPT_FMT, (int)GPT_PMBR_SECTORS,
+               (int)GPT_HEADER_SECTORS, "INVALID", "Pri GPT header");
+      }
 
-      require(snprintf(indent, sizeof(indent), GPT_MORE) < sizeof(indent));
-      header = (GptHeader*)drive->gpt.primary_header;
-      entries = (GptEntry*)drive->gpt.primary_entries;
-      HeaderDetails(header, entries, indent, params->numeric);
-    }
+      if (params->debug ||
+          ((drive->gpt.valid_headers & MASK_PRIMARY) && params->verbose)) {
+        GptHeader *header;
+        char indent[64];
 
-    GptHeader* primary_header = (GptHeader*)drive->gpt.primary_header;
-    printf(GPT_FMT, (int)primary_header->entries_lba,
-           (int)CalculateEntriesSectors(primary_header),
-           drive->gpt.valid_entries & MASK_PRIMARY ? "" : "INVALID",
-           "Pri GPT table");
+        require(snprintf(indent, sizeof(indent), GPT_MORE) < sizeof(indent));
+        header = (GptHeader*)drive->gpt.primary_header;
+        entries = (GptEntry*)drive->gpt.primary_entries;
+        HeaderDetails(header, entries, indent, params->numeric);
+      }
 
-    if (params->debug ||
-        (drive->gpt.valid_entries & MASK_PRIMARY))
-      EntriesDetails(drive, PRIMARY, params->numeric);
+      GptHeader* primary_header = (GptHeader*)drive->gpt.primary_header;
+      printf(GPT_FMT, (int)primary_header->entries_lba,
+             (int)CalculateEntriesSectors(primary_header),
+             drive->gpt.valid_entries & MASK_PRIMARY ? "" : "INVALID",
+             "Pri GPT table");
 
-    /****************************** Secondary *************************/
-    GptHeader* secondary_header = (GptHeader*)drive->gpt.secondary_header;
-    printf(GPT_FMT, (int)secondary_header->entries_lba,
-           (int)CalculateEntriesSectors(secondary_header),
-           drive->gpt.valid_entries & MASK_SECONDARY ? "" : "INVALID",
-           "Sec GPT table");
-    /* We show secondary table details if any of following is true.
-     *   1. in debug mode.
-     *   2. only secondary is valid.
-     *   3. secondary is not identical to promary.
-     */
-    if (params->debug ||
-        ((drive->gpt.valid_entries & MASK_SECONDARY) &&
-         (!(drive->gpt.valid_entries & MASK_PRIMARY) ||
-          memcmp(drive->gpt.primary_entries, drive->gpt.secondary_entries,
-                 secondary_header->number_of_entries *
-                 secondary_header->size_of_entry)))) {
-      EntriesDetails(drive, SECONDARY, params->numeric);
+      if (params->debug ||
+          (drive->gpt.valid_entries & MASK_PRIMARY))
+        EntriesDetails(drive, PRIMARY, params->numeric);
     }
 
-    if (drive->gpt.valid_headers & MASK_SECONDARY)
+    /****************************** Secondary *************************/
+    if (drive->gpt.ignored & MASK_SECONDARY) {
       printf(GPT_FMT, (int)(drive->gpt.gpt_drive_sectors - GPT_HEADER_SECTORS),
-             (int)GPT_HEADER_SECTORS, "", "Sec GPT header");
-    else
-      printf(GPT_FMT, (int)GPT_PMBR_SECTORS,
-             (int)GPT_HEADER_SECTORS, "INVALID", "Sec GPT header");
-    /* We show secondary header if any of following is true:
-     *   1. in debug mode.
-     *   2. only secondary is valid.
-     *   3. secondary is not synonymous to primary.
-     */
-    if (params->debug ||
-        ((drive->gpt.valid_headers & MASK_SECONDARY) &&
-         (!(drive->gpt.valid_headers & MASK_PRIMARY) ||
-          !IsSynonymous((GptHeader*)drive->gpt.primary_header,
-                        (GptHeader*)drive->gpt.secondary_header)) &&
-         params->verbose)) {
-      GptHeader *header;
-      char indent[64];
-
-      require(snprintf(indent, sizeof(indent), GPT_MORE) < sizeof(indent));
-      header = (GptHeader*)drive->gpt.secondary_header;
-      entries = (GptEntry*)drive->gpt.secondary_entries;
-      HeaderDetails(header, entries, indent, params->numeric);
+             (int)GPT_HEADER_SECTORS, "IGNORED", "Sec GPT header");
+    } else {
+      GptHeader* secondary_header = (GptHeader*)drive->gpt.secondary_header;
+      printf(GPT_FMT, (int)secondary_header->entries_lba,
+             (int)CalculateEntriesSectors(secondary_header),
+             drive->gpt.valid_entries & MASK_SECONDARY ? "" : "INVALID",
+             "Sec GPT table");
+      /* We show secondary table details if any of following is true.
+       *   1. in debug mode.
+       *   2. primary table is being ignored
+       *   3. only secondary is valid.
+       *   4. secondary is not identical to promary.
+       */
+      if (params->debug || (drive->gpt.ignored & MASK_PRIMARY) ||
+          ((drive->gpt.valid_entries & MASK_SECONDARY) &&
+           (!(drive->gpt.valid_entries & MASK_PRIMARY) ||
+            memcmp(drive->gpt.primary_entries, drive->gpt.secondary_entries,
+                   secondary_header->number_of_entries *
+                   secondary_header->size_of_entry)))) {
+        EntriesDetails(drive, SECONDARY, params->numeric);
+      }
+
+      if (drive->gpt.valid_headers & MASK_SECONDARY) {
+        printf(GPT_FMT, (int)(drive->gpt.gpt_drive_sectors - GPT_HEADER_SECTORS),
+               (int)GPT_HEADER_SECTORS, "", "Sec GPT header");
+      } else {
+        printf(GPT_FMT, (int)GPT_PMBR_SECTORS,
+               (int)GPT_HEADER_SECTORS, "INVALID", "Sec GPT header");
+      }
+      /* We show secondary header if any of following is true:
+       *   1. in debug mode.
+       *   2. only secondary is valid.
+       *   3. secondary is not synonymous to primary and not ignored.
+       */
+      if (params->debug ||
+          ((drive->gpt.valid_headers & MASK_SECONDARY) &&
+           (!(drive->gpt.valid_headers & MASK_PRIMARY) ||
+            !IsSynonymous((GptHeader*)drive->gpt.primary_header,
+                          (GptHeader*)drive->gpt.secondary_header)) &&
+           params->verbose)) {
+        GptHeader *header;
+        char indent[64];
+
+        require(snprintf(indent, sizeof(indent), GPT_MORE) < sizeof(indent));
+        header = (GptHeader*)drive->gpt.secondary_header;
+        entries = (GptEntry*)drive->gpt.secondary_entries;
+        HeaderDetails(header, entries, indent, params->numeric);
+      }
     }
   }