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>

10 files changed, 130 insertions, 123 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) {
diff --git a/firmware/include/gpt_misc.h b/firmware/include/gpt_misc.h
index 53b30347..e15f7dc8 100644
--- a/firmware/include/gpt_misc.h
+++ b/firmware/include/gpt_misc.h
@@ -57,10 +57,8 @@ enum {
 	GPT_UPDATE_ENTRY_BAD = 2,
 };
 
-enum {
-	GPT_STORED_ON_DEVICE = 0,   /* The GPT is stored on the same device. */
-	GPT_STORED_OFF_DEVICE = 1,  /* The GPT is stored on another place. */
-};
+/* If this bit is 1, the GPT is stored in another from the streaming data */
+#define GPT_FLAG_EXTERNAL	0x1
 
 /*
  * A note about stored_on_device and gpt_drive_sectors:
@@ -88,11 +86,11 @@ typedef struct {
 	/* Size of a LBA sector, in bytes */
 	uint32_t sector_bytes;
 	/* Size of drive (that the partitions are on) in LBA sectors */
-	uint64_t drive_sectors;
-	/* Are the GPT structures stored on the same device */
-	uint8_t stored_on_device;
+	uint64_t streaming_drive_sectors;
 	/* Size of the device that holds the GPT structures, 512-byte sectors */
 	uint64_t gpt_drive_sectors;
+	/* Flags */
+	uint32_t flags;
 
 	/* Outputs */
 	/* Which inputs have been modified?  GPT_MODIFIED_* */
diff --git a/firmware/lib/cgptlib/cgptlib_internal.c b/firmware/lib/cgptlib/cgptlib_internal.c
index 9bcfbd81..e7bb2e60 100644
--- a/firmware/lib/cgptlib/cgptlib_internal.c
+++ b/firmware/lib/cgptlib/cgptlib_internal.c
@@ -20,12 +20,13 @@ int CheckParameters(GptData *gpt)
 		return GPT_ERROR_INVALID_SECTOR_SIZE;
 
 	/*
-	 * gpt_drive_sectors should be reasonable. It cannot be unset, and it cannot
-	 * differ from drive_sectors if the GPT structs are stored on same device.
+	 * gpt_drive_sectors should be reasonable. It cannot be unset, and it
+	 * cannot differ from streaming_drive_sectors if the GPT structs are
+	 * stored on same device.
 	 */
 	if (gpt->gpt_drive_sectors == 0 ||
-		(gpt->stored_on_device == GPT_STORED_ON_DEVICE &&
-			gpt->gpt_drive_sectors != gpt->drive_sectors)) {
+		(!(gpt->flags & GPT_FLAG_EXTERNAL) &&
+		 gpt->gpt_drive_sectors != gpt->streaming_drive_sectors)) {
 		return GPT_ERROR_INVALID_SECTOR_NUMBER;
 	}
 
@@ -53,8 +54,9 @@ uint32_t HeaderCrc(GptHeader *h)
 	return crc32;
 }
 
-int CheckHeader(GptHeader *h, int is_secondary, uint64_t drive_sectors,
-		uint64_t gpt_drive_sectors, uint8_t stored_on_device)
+int CheckHeader(GptHeader *h, int is_secondary,
+		uint64_t streaming_drive_sectors,
+		uint64_t gpt_drive_sectors, uint32_t flags)
 {
 	if (!h)
 		return 1;
@@ -91,7 +93,7 @@ int CheckHeader(GptHeader *h, int is_secondary, uint64_t drive_sectors,
 		return 1;
 	if ((h->number_of_entries < MIN_NUMBER_OF_ENTRIES) ||
 	    (h->number_of_entries > MAX_NUMBER_OF_ENTRIES) ||
-	    (stored_on_device == GPT_STORED_ON_DEVICE &&
+	    (!(flags & GPT_FLAG_EXTERNAL) &&
 	    h->number_of_entries * h->size_of_entry != TOTAL_ENTRIES_SIZE))
 		return 1;
 
@@ -116,8 +118,8 @@ int CheckHeader(GptHeader *h, int is_secondary, uint64_t drive_sectors,
 	if (h->first_usable_lba > h->last_usable_lba)
 		return 1;
 
-	if (stored_on_device != GPT_STORED_ON_DEVICE) {
-		if (h->last_usable_lba >= drive_sectors) {
+	if (flags & GPT_FLAG_EXTERNAL) {
+		if (h->last_usable_lba >= streaming_drive_sectors) {
 			return 1;
 		}
 		return 0;
@@ -131,7 +133,8 @@ int CheckHeader(GptHeader *h, int is_secondary, uint64_t drive_sectors,
 	/* TODO(namnguyen): Also check for padding between header & entries. */
 	if (h->first_usable_lba < 2 + GPT_ENTRIES_SECTORS)
 		return 1;
-	if (h->last_usable_lba >= drive_sectors - 1 - GPT_ENTRIES_SECTORS)
+	if (h->last_usable_lba >=
+			streaming_drive_sectors - 1 - GPT_ENTRIES_SECTORS)
 		return 1;
 
 	/* Success */
@@ -245,13 +248,13 @@ int GptSanityCheck(GptData *gpt)
 		return retval;
 
 	/* Check both headers; we need at least one valid header. */
-	if (0 == CheckHeader(header1, 0, gpt->drive_sectors,
-			     gpt->gpt_drive_sectors, gpt->stored_on_device)) {
+	if (0 == CheckHeader(header1, 0, gpt->streaming_drive_sectors,
+			     gpt->gpt_drive_sectors, gpt->flags)) {
 		gpt->valid_headers |= MASK_PRIMARY;
 		goodhdr = header1;
 	}
-	if (0 == CheckHeader(header2, 1, gpt->drive_sectors,
-			     gpt->gpt_drive_sectors, gpt->stored_on_device)) {
+	if (0 == CheckHeader(header2, 1, gpt->streaming_drive_sectors,
+			     gpt->gpt_drive_sectors, gpt->flags)) {
 		gpt->valid_headers |= MASK_SECONDARY;
 		if (!goodhdr)
 			goodhdr = header2;
@@ -332,7 +335,8 @@ void GptRepair(GptData *gpt)
 		/* Secondary is good, primary is bad */
 		Memcpy(header1, header2, sizeof(GptHeader));
 		header1->my_lba = GPT_PMBR_SECTORS;  /* Second sector. */
-		header1->alternate_lba = gpt->drive_sectors - GPT_HEADER_SECTORS;
+		header1->alternate_lba =
+			gpt->streaming_drive_sectors - GPT_HEADER_SECTORS;
 		/* TODO (namnguyen): Preserve (header, entries) padding. */
 		header1->entries_lba = header1->my_lba + 1;
 		header1->header_crc32 = HeaderCrc(header1);
diff --git a/firmware/lib/cgptlib/include/cgptlib_internal.h b/firmware/lib/cgptlib/include/cgptlib_internal.h
index 825bbbb2..8dc05914 100644
--- a/firmware/lib/cgptlib/include/cgptlib_internal.h
+++ b/firmware/lib/cgptlib/include/cgptlib_internal.h
@@ -90,8 +90,9 @@ int CheckParameters(GptData* gpt);
  *
  * Returns 0 if header is valid, 1 if invalid.
  */
-int CheckHeader(GptHeader *h, int is_secondary, uint64_t drive_sectors,
-                uint64_t gpt_drive_sectors, uint8_t stored_on_device);
+int CheckHeader(GptHeader *h, int is_secondary,
+                uint64_t streaming_drive_sectors,
+                uint64_t gpt_drive_sectors, uint32_t flags);
 
 /**
  * Calculate and return the header CRC.
diff --git a/firmware/lib/gpt_misc.c b/firmware/lib/gpt_misc.c
index dc15d915..975e853b 100644
--- a/firmware/lib/gpt_misc.c
+++ b/firmware/lib/gpt_misc.c
@@ -48,9 +48,10 @@ int AllocAndReadGptData(VbExDiskHandle_t disk_handle, GptData *gptdata)
 
 	/* Only read primary GPT if the primary header is valid */
 	GptHeader* primary_header = (GptHeader*)gptdata->primary_header;
-	if (0 == CheckHeader(primary_header, 0, gptdata->drive_sectors,
+	if (0 == CheckHeader(primary_header, 0,
+			gptdata->streaming_drive_sectors,
 			gptdata->gpt_drive_sectors,
-			gptdata->stored_on_device)) {
+			gptdata->flags)) {
 		primary_valid = 1;
 		if (0 != VbExDiskRead(disk_handle,
 				      primary_header->entries_lba,
@@ -68,9 +69,10 @@ int AllocAndReadGptData(VbExDiskHandle_t disk_handle, GptData *gptdata)
 
 	/* Only read secondary GPT if the secondary header is valid */
 	GptHeader* secondary_header = (GptHeader*)gptdata->secondary_header;
-	if (0 == CheckHeader(secondary_header, 1, gptdata->drive_sectors,
+	if (0 == CheckHeader(secondary_header, 1,
+			gptdata->streaming_drive_sectors,
 			gptdata->gpt_drive_sectors,
-			gptdata->stored_on_device)) {
+			gptdata->flags)) {
 		secondary_valid = 1;
 		if (0 != VbExDiskRead(disk_handle,
 				      secondary_header->entries_lba,
diff --git a/firmware/lib/vboot_kernel.c b/firmware/lib/vboot_kernel.c
index 62e62967..5dd75de8 100644
--- a/firmware/lib/vboot_kernel.c
+++ b/firmware/lib/vboot_kernel.c
@@ -115,10 +115,10 @@ VbError_t LoadKernel(LoadKernelParams *params, VbCommonParams *cparams)
 
 	/* Read GPT data */
 	gpt.sector_bytes = (uint32_t)blba;
-	gpt.drive_sectors = params->ending_lba + 1;
+	gpt.streaming_drive_sectors = params->ending_lba + 1;
 	/* TODO: Set stored_on_device and gpt_drive_sectors appropriately */
-	gpt.stored_on_device = GPT_STORED_ON_DEVICE;
-	gpt.gpt_drive_sectors = gpt.drive_sectors;
+	gpt.gpt_drive_sectors = gpt.streaming_drive_sectors;
+	gpt.flags = 0;
 	if (0 != AllocAndReadGptData(params->disk_handle, &gpt)) {
 		VBDEBUG(("Unable to read GPT data\n"));
 		shcall->check_result = VBSD_LKC_CHECK_GPT_READ_ERROR;
diff --git a/tests/cgptlib_test.c b/tests/cgptlib_test.c
index fd5cda16..e81f50e7 100644
--- a/tests/cgptlib_test.c
+++ b/tests/cgptlib_test.c
@@ -149,7 +149,8 @@ static void BuildTestGptData(GptData *gpt)
 	Guid chromeos_rootfs = GPT_ENT_TYPE_CHROMEOS_ROOTFS;
 
 	gpt->sector_bytes = DEFAULT_SECTOR_SIZE;
-	gpt->drive_sectors = gpt->gpt_drive_sectors = DEFAULT_DRIVE_SECTORS;
+	gpt->streaming_drive_sectors =
+		gpt->gpt_drive_sectors = DEFAULT_DRIVE_SECTORS;
 	gpt->current_kernel = CGPT_KERNEL_ENTRY_NOT_FOUND;
 	gpt->valid_headers = MASK_BOTH;
 	gpt->valid_entries = MASK_BOTH;
@@ -255,7 +256,8 @@ static int ParameterTests(void)
 	for (i = 0; i < ARRAY_SIZE(cases); ++i) {
 		BuildTestGptData(gpt);
 		gpt->sector_bytes = cases[i].sector_bytes;
-		gpt->drive_sectors = gpt->gpt_drive_sectors = cases[i].drive_sectors;
+		gpt->streaming_drive_sectors =
+			gpt->gpt_drive_sectors = cases[i].drive_sectors;
 		EXPECT(cases[i].expected_retval == CheckParameters(gpt));
 	}
 
@@ -350,15 +352,15 @@ static int SignatureTest(void)
 	GptHeader *h2 = (GptHeader *)gpt->secondary_header;
 	int i;
 
-	EXPECT(1 == CheckHeader(NULL, 0, gpt->drive_sectors, gpt->gpt_drive_sectors, GPT_STORED_ON_DEVICE));
+	EXPECT(1 == CheckHeader(NULL, 0, gpt->streaming_drive_sectors, gpt->gpt_drive_sectors, 0));
 
 	for (i = 0; i < 8; ++i) {
 		BuildTestGptData(gpt);
 		h1->signature[i] ^= 0xff;
 		h2->signature[i] ^= 0xff;
 		RefreshCrc32(gpt);
-		EXPECT(1 == CheckHeader(h1, 0, gpt->drive_sectors, gpt->gpt_drive_sectors, GPT_STORED_ON_DEVICE));
-		EXPECT(1 == CheckHeader(h2, 1, gpt->drive_sectors, gpt->gpt_drive_sectors, GPT_STORED_ON_DEVICE));
+		EXPECT(1 == CheckHeader(h1, 0, gpt->streaming_drive_sectors, gpt->gpt_drive_sectors, 0));
+		EXPECT(1 == CheckHeader(h2, 1, gpt->streaming_drive_sectors, gpt->gpt_drive_sectors, 0));
 	}
 
 	return TEST_OK;
@@ -392,9 +394,9 @@ static int RevisionTest(void)
 		h2->revision = cases[i].value_to_test;
 		RefreshCrc32(gpt);
 
-		EXPECT(CheckHeader(h1, 0, gpt->drive_sectors, gpt->gpt_drive_sectors, GPT_STORED_ON_DEVICE) ==
+		EXPECT(CheckHeader(h1, 0, gpt->streaming_drive_sectors, gpt->gpt_drive_sectors, 0) ==
 		       cases[i].expect_rv);
-		EXPECT(CheckHeader(h2, 1, gpt->drive_sectors, gpt->gpt_drive_sectors, GPT_STORED_ON_DEVICE) ==
+		EXPECT(CheckHeader(h2, 1, gpt->streaming_drive_sectors, gpt->gpt_drive_sectors, 0) ==
 		       cases[i].expect_rv);
 	}
 	return TEST_OK;
@@ -425,9 +427,9 @@ static int SizeTest(void)
 		h2->size = cases[i].value_to_test;
 		RefreshCrc32(gpt);
 
-		EXPECT(CheckHeader(h1, 0, gpt->drive_sectors, gpt->gpt_drive_sectors, GPT_STORED_ON_DEVICE) ==
+		EXPECT(CheckHeader(h1, 0, gpt->streaming_drive_sectors, gpt->gpt_drive_sectors, 0) ==
 		       cases[i].expect_rv);
-		EXPECT(CheckHeader(h2, 1, gpt->drive_sectors, gpt->gpt_drive_sectors, GPT_STORED_ON_DEVICE) ==
+		EXPECT(CheckHeader(h2, 1, gpt->streaming_drive_sectors, gpt->gpt_drive_sectors, 0) ==
 		       cases[i].expect_rv);
 	}
 	return TEST_OK;
@@ -444,12 +446,12 @@ static int CrcFieldTest(void)
 	/* Modify a field that the header verification doesn't care about */
 	h1->entries_crc32++;
 	h2->entries_crc32++;
-	EXPECT(1 == CheckHeader(h1, 0, gpt->drive_sectors, gpt->gpt_drive_sectors, GPT_STORED_ON_DEVICE));
-	EXPECT(1 == CheckHeader(h2, 1, gpt->drive_sectors, gpt->gpt_drive_sectors, GPT_STORED_ON_DEVICE));
+	EXPECT(1 == CheckHeader(h1, 0, gpt->streaming_drive_sectors, gpt->gpt_drive_sectors, 0));
+	EXPECT(1 == CheckHeader(h2, 1, gpt->streaming_drive_sectors, gpt->gpt_drive_sectors, 0));
 	/* Refresh the CRC; should pass now */
 	RefreshCrc32(gpt);
-	EXPECT(0 == CheckHeader(h1, 0, gpt->drive_sectors, gpt->gpt_drive_sectors, GPT_STORED_ON_DEVICE));
-	EXPECT(0 == CheckHeader(h2, 1, gpt->drive_sectors, gpt->gpt_drive_sectors, GPT_STORED_ON_DEVICE));
+	EXPECT(0 == CheckHeader(h1, 0, gpt->streaming_drive_sectors, gpt->gpt_drive_sectors, 0));
+	EXPECT(0 == CheckHeader(h2, 1, gpt->streaming_drive_sectors, gpt->gpt_drive_sectors, 0));
 
 	return TEST_OK;
 }
@@ -465,8 +467,8 @@ static int ReservedFieldsTest(void)
 	h1->reserved_zero ^= 0x12345678;  /* whatever random */
 	h2->reserved_zero ^= 0x12345678;  /* whatever random */
 	RefreshCrc32(gpt);
-	EXPECT(1 == CheckHeader(h1, 0, gpt->drive_sectors, gpt->gpt_drive_sectors, GPT_STORED_ON_DEVICE));
-	EXPECT(1 == CheckHeader(h2, 1, gpt->drive_sectors, gpt->gpt_drive_sectors, GPT_STORED_ON_DEVICE));
+	EXPECT(1 == CheckHeader(h1, 0, gpt->streaming_drive_sectors, gpt->gpt_drive_sectors, 0));
+	EXPECT(1 == CheckHeader(h2, 1, gpt->streaming_drive_sectors, gpt->gpt_drive_sectors, 0));
 
 #ifdef PADDING_CHECKED
 	/* TODO: padding check is currently disabled */
@@ -474,8 +476,8 @@ static int ReservedFieldsTest(void)
 	h1->padding[12] ^= 0x34;  /* whatever random */
 	h2->padding[56] ^= 0x78;  /* whatever random */
 	RefreshCrc32(gpt);
-	EXPECT(1 == CheckHeader(h1, 0, gpt->drive_sectors, gpt->gpt_drive_sectors, GPT_STORED_ON_DEVICE));
-	EXPECT(1 == CheckHeader(h2, 1, gpt->drive_sectors, gpt->gpt_drive_sectors, GPT_STORED_ON_DEVICE));
+	EXPECT(1 == CheckHeader(h1, 0, gpt->streaming_drive_sectors, gpt->gpt_drive_sectors, 0));
+	EXPECT(1 == CheckHeader(h2, 1, gpt->streaming_drive_sectors, gpt->gpt_drive_sectors, 0));
 #endif
 
 	return TEST_OK;
@@ -513,9 +515,9 @@ static int SizeOfPartitionEntryTest(void) {
 			cases[i].value_to_test;
 		RefreshCrc32(gpt);
 
-		EXPECT(CheckHeader(h1, 0, gpt->drive_sectors, gpt->gpt_drive_sectors, GPT_STORED_ON_DEVICE) ==
+		EXPECT(CheckHeader(h1, 0, gpt->streaming_drive_sectors, gpt->gpt_drive_sectors, 0) ==
 		       cases[i].expect_rv);
-		EXPECT(CheckHeader(h2, 1, gpt->drive_sectors, gpt->gpt_drive_sectors, GPT_STORED_ON_DEVICE) ==
+		EXPECT(CheckHeader(h2, 1, gpt->streaming_drive_sectors, gpt->gpt_drive_sectors, 0) ==
 		       cases[i].expect_rv);
 	}
 
@@ -536,11 +538,11 @@ static int NumberOfPartitionEntriesTest(void)
 	h1->number_of_entries--;
 	h2->number_of_entries /= 2;
 	RefreshCrc32(gpt);
-	EXPECT(1 == CheckHeader(h1, 0, gpt->drive_sectors, gpt->gpt_drive_sectors, GPT_STORED_ON_DEVICE));
-	EXPECT(1 == CheckHeader(h2, 1, gpt->drive_sectors, gpt->gpt_drive_sectors, GPT_STORED_ON_DEVICE));
+	EXPECT(1 == CheckHeader(h1, 0, gpt->streaming_drive_sectors, gpt->gpt_drive_sectors, 0));
+	EXPECT(1 == CheckHeader(h2, 1, gpt->streaming_drive_sectors, gpt->gpt_drive_sectors, 0));
 	/* But it's okay to have less if the GPT structs are stored elsewhere. */
-	EXPECT(0 == CheckHeader(h1, 0, gpt->drive_sectors, gpt->gpt_drive_sectors, GPT_STORED_OFF_DEVICE));
-	EXPECT(0 == CheckHeader(h2, 1, gpt->drive_sectors, gpt->gpt_drive_sectors, GPT_STORED_OFF_DEVICE));
+	EXPECT(0 == CheckHeader(h1, 0, gpt->streaming_drive_sectors, gpt->gpt_drive_sectors, GPT_FLAG_EXTERNAL));
+	EXPECT(0 == CheckHeader(h2, 1, gpt->streaming_drive_sectors, gpt->gpt_drive_sectors, GPT_FLAG_EXTERNAL));
 
 	return TEST_OK;
 }
@@ -555,37 +557,37 @@ static int MyLbaTest(void)
 
 	/* myLBA depends on primary vs secondary flag */
 	BuildTestGptData(gpt);
-	EXPECT(1 == CheckHeader(h1, 1, gpt->drive_sectors, gpt->gpt_drive_sectors, GPT_STORED_ON_DEVICE));
-	EXPECT(1 == CheckHeader(h2, 0, gpt->drive_sectors, gpt->gpt_drive_sectors, GPT_STORED_ON_DEVICE));
+	EXPECT(1 == CheckHeader(h1, 1, gpt->streaming_drive_sectors, gpt->gpt_drive_sectors, 0));
+	EXPECT(1 == CheckHeader(h2, 0, gpt->streaming_drive_sectors, gpt->gpt_drive_sectors, 0));
 
 	BuildTestGptData(gpt);
 	h1->my_lba--;
 	h2->my_lba--;
 	RefreshCrc32(gpt);
-	EXPECT(1 == CheckHeader(h1, 0, gpt->drive_sectors, gpt->gpt_drive_sectors, GPT_STORED_ON_DEVICE));
-	EXPECT(1 == CheckHeader(h2, 1, gpt->drive_sectors, gpt->gpt_drive_sectors, GPT_STORED_ON_DEVICE));
+	EXPECT(1 == CheckHeader(h1, 0, gpt->streaming_drive_sectors, gpt->gpt_drive_sectors, 0));
+	EXPECT(1 == CheckHeader(h2, 1, gpt->streaming_drive_sectors, gpt->gpt_drive_sectors, 0));
 
 	BuildTestGptData(gpt);
 	h1->my_lba = 2;
 	h2->my_lba--;
 	RefreshCrc32(gpt);
-	EXPECT(1 == CheckHeader(h1, 0, gpt->drive_sectors, gpt->gpt_drive_sectors, GPT_STORED_ON_DEVICE));
-	EXPECT(1 == CheckHeader(h2, 1, gpt->drive_sectors, gpt->gpt_drive_sectors, GPT_STORED_ON_DEVICE));
+	EXPECT(1 == CheckHeader(h1, 0, gpt->streaming_drive_sectors, gpt->gpt_drive_sectors, 0));
+	EXPECT(1 == CheckHeader(h2, 1, gpt->streaming_drive_sectors, gpt->gpt_drive_sectors, 0));
 
 	/* We should ignore the alternate_lba field entirely */
 	BuildTestGptData(gpt);
 	h1->alternate_lba++;
 	h2->alternate_lba++;
 	RefreshCrc32(gpt);
-	EXPECT(0 == CheckHeader(h1, 0, gpt->drive_sectors, gpt->gpt_drive_sectors, GPT_STORED_ON_DEVICE));
-	EXPECT(0 == CheckHeader(h2, 1, gpt->drive_sectors, gpt->gpt_drive_sectors, GPT_STORED_ON_DEVICE));
+	EXPECT(0 == CheckHeader(h1, 0, gpt->streaming_drive_sectors, gpt->gpt_drive_sectors, 0));
+	EXPECT(0 == CheckHeader(h2, 1, gpt->streaming_drive_sectors, gpt->gpt_drive_sectors, 0));
 
 	BuildTestGptData(gpt);
 	h1->alternate_lba--;
 	h2->alternate_lba--;
 	RefreshCrc32(gpt);
-	EXPECT(0 == CheckHeader(h1, 0, gpt->drive_sectors, gpt->gpt_drive_sectors, GPT_STORED_ON_DEVICE));
-	EXPECT(0 == CheckHeader(h2, 1, gpt->drive_sectors, gpt->gpt_drive_sectors, GPT_STORED_ON_DEVICE));
+	EXPECT(0 == CheckHeader(h1, 0, gpt->streaming_drive_sectors, gpt->gpt_drive_sectors, 0));
+	EXPECT(0 == CheckHeader(h2, 1, gpt->streaming_drive_sectors, gpt->gpt_drive_sectors, 0));
 
 	BuildTestGptData(gpt);
 	h1->entries_lba++;
@@ -595,19 +597,19 @@ static int MyLbaTest(void)
 	 * We support a padding between primary GPT header and its entries. So
 	 * this still passes.
 	 */
-	EXPECT(0 == CheckHeader(h1, 0, gpt->drive_sectors, gpt->gpt_drive_sectors, GPT_STORED_ON_DEVICE));
+	EXPECT(0 == CheckHeader(h1, 0, gpt->streaming_drive_sectors, gpt->gpt_drive_sectors, 0));
 	/*
 	 * But the secondary table should fail because it would overlap the
 	 * header, which is now lying after its entry array.
 	 */
-	EXPECT(1 == CheckHeader(h2, 1, gpt->drive_sectors, gpt->gpt_drive_sectors, GPT_STORED_ON_DEVICE));
+	EXPECT(1 == CheckHeader(h2, 1, gpt->streaming_drive_sectors, gpt->gpt_drive_sectors, 0));
 
 	BuildTestGptData(gpt);
 	h1->entries_lba--;
 	h2->entries_lba--;
 	RefreshCrc32(gpt);
-	EXPECT(1 == CheckHeader(h1, 0, gpt->drive_sectors, gpt->gpt_drive_sectors, GPT_STORED_ON_DEVICE));
-	EXPECT(1 == CheckHeader(h2, 1, gpt->drive_sectors, gpt->gpt_drive_sectors, GPT_STORED_ON_DEVICE));
+	EXPECT(1 == CheckHeader(h1, 0, gpt->streaming_drive_sectors, gpt->gpt_drive_sectors, 0));
+	EXPECT(1 == CheckHeader(h2, 1, gpt->streaming_drive_sectors, gpt->gpt_drive_sectors, 0));
 
 	return TEST_OK;
 }
@@ -656,9 +658,9 @@ static int FirstUsableLbaAndLastUsableLbaTest(void)
 		h2->last_usable_lba = cases[i].secondary_last_usable_lba;
 		RefreshCrc32(gpt);
 
-		EXPECT(CheckHeader(h1, 0, gpt->drive_sectors, gpt->gpt_drive_sectors, GPT_STORED_ON_DEVICE) ==
+		EXPECT(CheckHeader(h1, 0, gpt->streaming_drive_sectors, gpt->gpt_drive_sectors, 0) ==
 		       cases[i].primary_rv);
-		EXPECT(CheckHeader(h2, 1, gpt->drive_sectors, gpt->gpt_drive_sectors, GPT_STORED_ON_DEVICE) ==
+		EXPECT(CheckHeader(h2, 1, gpt->streaming_drive_sectors, gpt->gpt_drive_sectors, 0) ==
 		       cases[i].secondary_rv);
 	}
 
@@ -1424,50 +1426,50 @@ static int CheckHeaderOffDevice()
 	RefreshCrc32(gpt);
 	// GPT is stored on the same device so first usable lba should not
 	// start at 0.
-	EXPECT(1 == CheckHeader(primary_header, 0, gpt->drive_sectors,
-		gpt->gpt_drive_sectors, GPT_STORED_ON_DEVICE));
+	EXPECT(1 == CheckHeader(primary_header, 0, gpt->streaming_drive_sectors,
+		gpt->gpt_drive_sectors, 0));
 	// But off device, it is okay to accept this GPT header.
-	EXPECT(0 == CheckHeader(primary_header, 0, gpt->drive_sectors,
-		gpt->gpt_drive_sectors, GPT_STORED_OFF_DEVICE));
+	EXPECT(0 == CheckHeader(primary_header, 0, gpt->streaming_drive_sectors,
+		gpt->gpt_drive_sectors, GPT_FLAG_EXTERNAL));
 
 	BuildTestGptData(gpt);
 	primary_header->number_of_entries = 100;
 	RefreshCrc32(gpt);
 	// Normally, number of entries is 128. So this should fail.
-	EXPECT(1 == CheckHeader(primary_header, 0, gpt->drive_sectors,
-		gpt->gpt_drive_sectors, GPT_STORED_ON_DEVICE));
+	EXPECT(1 == CheckHeader(primary_header, 0, gpt->streaming_drive_sectors,
+		gpt->gpt_drive_sectors, 0));
 	// But off device, it is okay.
-	EXPECT(0 == CheckHeader(primary_header, 0, gpt->drive_sectors,
-		gpt->gpt_drive_sectors, GPT_STORED_OFF_DEVICE));
+	EXPECT(0 == CheckHeader(primary_header, 0, gpt->streaming_drive_sectors,
+		gpt->gpt_drive_sectors, GPT_FLAG_EXTERNAL));
 
 	primary_header->number_of_entries = MIN_NUMBER_OF_ENTRIES - 1;
 	RefreshCrc32(gpt);
 	// However, too few entries is not good.
-	EXPECT(1 == CheckHeader(primary_header, 0, gpt->drive_sectors,
-		gpt->gpt_drive_sectors, GPT_STORED_OFF_DEVICE));
+	EXPECT(1 == CheckHeader(primary_header, 0, gpt->streaming_drive_sectors,
+		gpt->gpt_drive_sectors, GPT_FLAG_EXTERNAL));
 
 	// Repeat for secondary header.
 	BuildTestGptData(gpt);
 	GptHeader* secondary_header = (GptHeader*)gpt->secondary_header;
 	secondary_header->first_usable_lba = 0;
 	RefreshCrc32(gpt);
-	EXPECT(1 == CheckHeader(secondary_header, 1, gpt->drive_sectors,
-		gpt->gpt_drive_sectors, GPT_STORED_ON_DEVICE));
-	EXPECT(0 == CheckHeader(secondary_header, 1, gpt->drive_sectors,
-		gpt->gpt_drive_sectors, GPT_STORED_OFF_DEVICE));
+	EXPECT(1 == CheckHeader(secondary_header, 1, gpt->streaming_drive_sectors,
+		gpt->gpt_drive_sectors, 0));
+	EXPECT(0 == CheckHeader(secondary_header, 1, gpt->streaming_drive_sectors,
+		gpt->gpt_drive_sectors, GPT_FLAG_EXTERNAL));
 
 	BuildTestGptData(gpt);
 	secondary_header->number_of_entries = 100;
 	RefreshCrc32(gpt);
-	EXPECT(1 == CheckHeader(secondary_header, 1, gpt->drive_sectors,
-		gpt->gpt_drive_sectors, GPT_STORED_ON_DEVICE));
-	EXPECT(0 == CheckHeader(secondary_header, 1, gpt->drive_sectors,
-		gpt->gpt_drive_sectors, GPT_STORED_OFF_DEVICE));
+	EXPECT(1 == CheckHeader(secondary_header, 1, gpt->streaming_drive_sectors,
+		gpt->gpt_drive_sectors, 0));
+	EXPECT(0 == CheckHeader(secondary_header, 1, gpt->streaming_drive_sectors,
+		gpt->gpt_drive_sectors, GPT_FLAG_EXTERNAL));
 
 	secondary_header->number_of_entries = MIN_NUMBER_OF_ENTRIES - 1;
 	RefreshCrc32(gpt);
-	EXPECT(1 == CheckHeader(secondary_header, 1, gpt->drive_sectors,
-		gpt->gpt_drive_sectors, GPT_STORED_OFF_DEVICE));
+	EXPECT(1 == CheckHeader(secondary_header, 1, gpt->streaming_drive_sectors,
+		gpt->gpt_drive_sectors, GPT_FLAG_EXTERNAL));
 
 	return TEST_OK;
 }
diff --git a/tests/vboot_kernel_tests.c b/tests/vboot_kernel_tests.c
index c546ed12..6f47ae35 100644
--- a/tests/vboot_kernel_tests.c
+++ b/tests/vboot_kernel_tests.c
@@ -289,7 +289,7 @@ static void ReadWriteGptTest(void)
 	GptHeader *h;
 
 	g.sector_bytes = MOCK_SECTOR_SIZE;
-	g.drive_sectors = g.gpt_drive_sectors = MOCK_SECTOR_COUNT;
+	g.streaming_drive_sectors = g.gpt_drive_sectors = MOCK_SECTOR_COUNT;
 	g.valid_headers = g.valid_entries = MASK_BOTH;
 
 	ResetMocks();
@@ -315,11 +315,11 @@ static void ReadWriteGptTest(void)
 	Memset(mock_gpt_primary, '\0', sizeof(*mock_gpt_primary));
 	TEST_EQ(AllocAndReadGptData(handle, &g), 0,
 		"AllocAndRead primary invalid");
-	TEST_EQ(CheckHeader(mock_gpt_primary, 0, g.drive_sectors,
-                g.gpt_drive_sectors, GPT_STORED_ON_DEVICE),
+	TEST_EQ(CheckHeader(mock_gpt_primary, 0, g.streaming_drive_sectors,
+                g.gpt_drive_sectors, 0),
                 1, "Primary header is invalid");
-	TEST_EQ(CheckHeader(mock_gpt_secondary, 1, g.drive_sectors,
-		g.gpt_drive_sectors, GPT_STORED_ON_DEVICE),
+	TEST_EQ(CheckHeader(mock_gpt_secondary, 1, g.streaming_drive_sectors,
+		g.gpt_drive_sectors, 0),
                 0, "Secondary header is valid");
 	TEST_CALLS("VbExDiskRead(h, 1, 1)\n"
 		   "VbExDiskRead(h, 1023, 1)\n"
@@ -334,11 +334,11 @@ static void ReadWriteGptTest(void)
 	Memset(mock_gpt_secondary, '\0', sizeof(*mock_gpt_secondary));
 	TEST_EQ(AllocAndReadGptData(handle, &g), 0,
 		"AllocAndRead secondary invalid");
-	TEST_EQ(CheckHeader(mock_gpt_primary, 0, g.drive_sectors,
-		g.gpt_drive_sectors, GPT_STORED_ON_DEVICE),
+	TEST_EQ(CheckHeader(mock_gpt_primary, 0, g.streaming_drive_sectors,
+		g.gpt_drive_sectors, 0),
                 0, "Primary header is valid");
-	TEST_EQ(CheckHeader(mock_gpt_secondary, 1, g.drive_sectors,
-		g.gpt_drive_sectors, GPT_STORED_ON_DEVICE),
+	TEST_EQ(CheckHeader(mock_gpt_secondary, 1, g.streaming_drive_sectors,
+		g.gpt_drive_sectors, 0),
                 1, "Secondary header is invalid");
 	TEST_CALLS("VbExDiskRead(h, 1, 1)\n"
 		   "VbExDiskRead(h, 2, 32)\n"
@@ -354,11 +354,11 @@ static void ReadWriteGptTest(void)
 	Memset(mock_gpt_secondary, '\0', sizeof(*mock_gpt_secondary));
 	TEST_EQ(AllocAndReadGptData(handle, &g), 1,
 		"AllocAndRead primary and secondary invalid");
-	TEST_EQ(CheckHeader(mock_gpt_primary, 0, g.drive_sectors,
-		g.gpt_drive_sectors, GPT_STORED_ON_DEVICE),
+	TEST_EQ(CheckHeader(mock_gpt_primary, 0, g.streaming_drive_sectors,
+		g.gpt_drive_sectors, 0),
                 1, "Primary header is invalid");
-	TEST_EQ(CheckHeader(mock_gpt_secondary, 1, g.drive_sectors,
-		g.gpt_drive_sectors, GPT_STORED_ON_DEVICE),
+	TEST_EQ(CheckHeader(mock_gpt_secondary, 1, g.streaming_drive_sectors,
+		g.gpt_drive_sectors, 0),
                 1, "Secondary header is invalid");
 	TEST_CALLS("VbExDiskRead(h, 1, 1)\n"
 		   "VbExDiskRead(h, 1023, 1)\n");
@@ -385,8 +385,8 @@ static void ReadWriteGptTest(void)
 		   "VbExDiskRead(h, 991, 32)\n"
 		   "VbExDiskWrite(h, 1, 1)\n"
 		   "VbExDiskWrite(h, 2, 32)\n");
-	TEST_EQ(CheckHeader(mock_gpt_primary, 0, g.drive_sectors,
-		g.gpt_drive_sectors, GPT_STORED_ON_DEVICE),
+	TEST_EQ(CheckHeader(mock_gpt_primary, 0, g.streaming_drive_sectors,
+		g.gpt_drive_sectors, 0),
                 0, "Fix Primary GPT: Primary header is valid");
 
 	/*
@@ -410,8 +410,8 @@ static void ReadWriteGptTest(void)
 		   "VbExDiskRead(h, 1023, 1)\n"
 		   "VbExDiskWrite(h, 1023, 1)\n"
 		   "VbExDiskWrite(h, 991, 32)\n");
-	TEST_EQ(CheckHeader(mock_gpt_secondary, 1, g.drive_sectors,
-		g.gpt_drive_sectors, GPT_STORED_ON_DEVICE),
+	TEST_EQ(CheckHeader(mock_gpt_secondary, 1, g.streaming_drive_sectors,
+		g.gpt_drive_sectors, 0),
                 0, "Fix Secondary GPT: Secondary header is valid");
 
 	/* Data which is changed is written */