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[v3,2/2] Fix image update with image smaller than 10KiB

Message ID 1449585133-9384-2-git-send-email-alban.bedel@avionic-design.de
State Deferred
Headers show

Commit Message

Alban Bedel Dec. 8, 2015, 2:32 p.m. UTC 
The BCT size check assume a quiet large image, however if the image
doesn't contains a bootloader it won't be that large. Change the size
check to only read the minimum data needed to verify the BCT version
and get the size.

Signed-off-by: Alban Bedel <alban.bedel@avionic-design.de>
--
Changelog:
v2: * Add a comment to explain the value of NVBOOT_CONFIG_TABLE_SIZE_MIN
v3: * Only read the minimum data needed
---
 src/cbootimage.h  | 14 ++++++++++++++
 src/data_layout.c |  4 ++--
 2 files changed, 16 insertions(+), 2 deletions(-)
diff mbox

Patch

diff --git a/src/cbootimage.h b/src/cbootimage.h
index 63f0ee9..ba2d997 100644
--- a/src/cbootimage.h
+++ b/src/cbootimage.h
@@ -49,6 +49,20 @@ 
 
 #define MAX_MTS_SIZE (4 * 1024 * 1024)
 
+/* Minimum size to read to at least be able to validate a BCT, it must
+ * include the boot_data_version field with any BCT version while not
+ * beeing larger than the smallest possible BCT. The currently supported
+ * BCT are as follow:
+ *
+ * Chip		Version offset	Total size
+ * T20		32		4080
+ * T30		32		6128
+ * T114		1792		8192
+ * T124		1744		8192
+ * T132		1744		8704
+ * T210		1328		10240
+ */
+#define NVBOOT_CONFIG_TABLE_SIZE_MIN 4080
 #define NVBOOT_CONFIG_TABLE_SIZE_MAX (10 * 1024)
 
 /*
diff --git a/src/data_layout.c b/src/data_layout.c
index 460310d..0eace5f 100644
--- a/src/data_layout.c
+++ b/src/data_layout.c
@@ -1044,7 +1044,7 @@  int data_is_valid_bct(build_image_context *context)
 
 int get_bct_size_from_image(build_image_context *context)
 {
-	u_int8_t buffer[NVBOOT_CONFIG_TABLE_SIZE_MAX];
+	u_int8_t buffer[NVBOOT_CONFIG_TABLE_SIZE_MIN];
 	u_int32_t bct_size = 0;
 	FILE *fp;
 
@@ -1052,7 +1052,7 @@  int get_bct_size_from_image(build_image_context *context)
 	if (!fp)
 		return -ENODATA;
 
-	if (fread(buffer, 1, NVBOOT_CONFIG_TABLE_SIZE_MAX, fp) != NVBOOT_CONFIG_TABLE_SIZE_MAX) {
+	if (fread(buffer, 1, NVBOOT_CONFIG_TABLE_SIZE_MIN, fp) != NVBOOT_CONFIG_TABLE_SIZE_MIN) {
 		fclose(fp);
 		return -ENODATA;
 	}