vboot: GPT interface cleanup

- Rename drive_sectors to streaming_drive_sectors, to contrast with
  gpt_drive_sectors
- Replace stored_on_device field with flags field for future
  extensibility

BUG=chromium:433433
TEST=make runtests
BRANCH=none

Change-Id: I785a3b735b8eb96f647a334659329db3ee43eb80
Signed-off-by: Dan Ehrenberg <dehrenberg@chromium.org>
Reviewed-on: https://chromium-review.googlesource.com/234283
Reviewed-by: Bill Richardson <wfrichar@chromium.org>

3 files changed, 16 insertions, 16 deletions

diff --git a/cgpt/cgpt_boot.c b/cgpt/cgpt_boot.c
index f4323962..d8976c42 100644
--- a/cgpt/cgpt_boot.c
+++ b/cgpt/cgpt_boot.c
@@ -99,8 +99,8 @@ int CgptBoot(CgptBootParams *params) {
     drive.pmbr.part[0].l_cyl = 0xff;
     drive.pmbr.part[0].f_lba = htole32(1);
     uint32_t max = 0xffffffff;
-    if (drive.gpt.drive_sectors < 0xffffffff)
-      max = drive.gpt.drive_sectors - 1;
+    if (drive.gpt.streaming_drive_sectors < 0xffffffff)
+      max = drive.gpt.streaming_drive_sectors - 1;
     drive.pmbr.part[0].num_sect = htole32(max);
   }
 
diff --git a/cgpt/cgpt_common.c b/cgpt/cgpt_common.c
index 1438dfb3..b580e33a 100644
--- a/cgpt/cgpt_common.c
+++ b/cgpt/cgpt_common.c
@@ -150,11 +150,11 @@ static int GptLoad(struct drive *drive, uint32_t sector_bytes) {
           (long long unsigned int)drive->size, drive->gpt.sector_bytes);
     return -1;
   }
-  drive->gpt.drive_sectors = drive->size / drive->gpt.sector_bytes;
+  drive->gpt.streaming_drive_sectors = drive->size / drive->gpt.sector_bytes;
 
   /* TODO(namnguyen): Remove this and totally trust gpt_drive_sectors. */
-  if (drive->gpt.stored_on_device == GPT_STORED_ON_DEVICE) {
-    drive->gpt.gpt_drive_sectors = drive->gpt.drive_sectors;
+  if (!(drive->gpt.flags & GPT_FLAG_EXTERNAL)) {
+    drive->gpt.gpt_drive_sectors = drive->gpt.streaming_drive_sectors;
   } /* Else, we trust gpt.gpt_drive_sectors. */
 
   // Read the data.
@@ -171,9 +171,9 @@ static int GptLoad(struct drive *drive, uint32_t sector_bytes) {
     return -1;
   }
   GptHeader* primary_header = (GptHeader*)drive->gpt.primary_header;
-  if (CheckHeader(primary_header, 0, drive->gpt.drive_sectors,
+  if (CheckHeader(primary_header, 0, drive->gpt.streaming_drive_sectors,
                   drive->gpt.gpt_drive_sectors,
-                  drive->gpt.stored_on_device) == 0) {
+                  drive->gpt.flags) == 0) {
     if (CGPT_OK != Load(drive, &drive->gpt.primary_entries,
                         primary_header->entries_lba,
                         drive->gpt.sector_bytes, GPT_ENTRIES_SECTORS)) {
@@ -184,9 +184,9 @@ static int GptLoad(struct drive *drive, uint32_t sector_bytes) {
     Warning("Primary GPT header is invalid\n");
   }
   GptHeader* secondary_header = (GptHeader*)drive->gpt.secondary_header;
-  if (CheckHeader(secondary_header, 1, drive->gpt.drive_sectors,
+  if (CheckHeader(secondary_header, 1, drive->gpt.streaming_drive_sectors,
                   drive->gpt.gpt_drive_sectors,
-                  drive->gpt.stored_on_device) == 0) {
+                  drive->gpt.flags) == 0) {
     if (CGPT_OK != Load(drive, &drive->gpt.secondary_entries,
                         secondary_header->entries_lba,
                         drive->gpt.sector_bytes, GPT_ENTRIES_SECTORS)) {
@@ -284,7 +284,6 @@ int DriveOpen(const char *drive_path, struct drive *drive, int mode,
 
   // Clear struct for proper error handling.
   memset(drive, 0, sizeof(struct drive));
-  drive->gpt.stored_on_device = GPT_STORED_ON_DEVICE;
 
   drive->fd = open(drive_path, mode | O_LARGEFILE | O_NOFOLLOW);
   if (drive->fd == -1) {
@@ -303,10 +302,10 @@ int DriveOpen(const char *drive_path, struct drive *drive, int mode,
   drive->gpt.gpt_drive_sectors = gpt_drive_size / sector_bytes;
   if (drive_size == 0) {
     drive->size = gpt_drive_size;
-    drive->gpt.stored_on_device = GPT_STORED_ON_DEVICE;
+    drive->gpt.flags = 0;
   } else {
     drive->size = drive_size;
-    drive->gpt.stored_on_device = GPT_STORED_OFF_DEVICE;
+    drive->gpt.flags = GPT_FLAG_EXTERNAL;
   }
 
 
diff --git a/cgpt/cgpt_create.c b/cgpt/cgpt_create.c
index 298e2ae5..2265c8f9 100644
--- a/cgpt/cgpt_create.c
+++ b/cgpt/cgpt_create.c
@@ -46,14 +46,15 @@ static int GptCreate(struct drive *drive, CgptCreateParams *params) {
     h->my_lba = GPT_PMBR_SECTORS;  /* The second sector on drive. */
     h->alternate_lba = drive->gpt.gpt_drive_sectors - GPT_HEADER_SECTORS;
     h->entries_lba = h->my_lba + GPT_HEADER_SECTORS;
-    if (drive->gpt.stored_on_device == GPT_STORED_ON_DEVICE) {
+    if (!(drive->gpt.flags & GPT_FLAG_EXTERNAL)) {
       h->entries_lba += params->padding;
       h->first_usable_lba = h->entries_lba + GPT_ENTRIES_SECTORS;
-      h->last_usable_lba = (drive->gpt.drive_sectors - GPT_HEADER_SECTORS -
+      h->last_usable_lba = (drive->gpt.streaming_drive_sectors -
+			    GPT_HEADER_SECTORS -
                             GPT_ENTRIES_SECTORS - 1);
     } else {
       h->first_usable_lba = params->padding;
-      h->last_usable_lba = (drive->gpt.drive_sectors - 1);
+      h->last_usable_lba = (drive->gpt.streaming_drive_sectors - 1);
     }
     if (CGPT_OK != GenerateGuid(&h->disk_uuid)) {
       Error("Unable to generate new GUID.\n");
@@ -61,7 +62,7 @@ static int GptCreate(struct drive *drive, CgptCreateParams *params) {
     }
     h->size_of_entry = sizeof(GptEntry);
     h->number_of_entries = TOTAL_ENTRIES_SIZE / h->size_of_entry;
-    if (drive->gpt.stored_on_device != GPT_STORED_ON_DEVICE) {
+    if (drive->gpt.flags & GPT_FLAG_EXTERNAL) {
       // We might have smaller space for the GPT table. Scale accordingly.
       size_t half_size_sectors = drive->gpt.gpt_drive_sectors / 2;
       if (half_size_sectors < GPT_HEADER_SECTORS) {