[Suspend2][ 10/35] [Suspend2] Parse filewriter signature.

[Nigel Cunningham <nigel@suspend2.net>]

Given a pointer to what we expect to be a filewriter signature, return
whether it is unrecognised (-1), a file without an image (0) or a file with
an image to resume from (1).

Signed-off-by: Nigel Cunningham <nigel@suspend2.net>

 kernel/power/suspend_file.c |   20 ++++++++++++++++++++
 1 files changed, 20 insertions(+), 0 deletions(-)

diff --git a/kernel/power/suspend_file.c b/kernel/power/suspend_file.c
index 6851977..d5f0310 100644
--- a/kernel/power/suspend_file.c
+++ b/kernel/power/suspend_file.c
@@ -365,3 +365,23 @@ cleanup:
 	target_storage_available = 0;
 }
 
+int parse_signature(struct filewriter_header *header)
+{
+	int have_image = !memcmp(HaveImage, header->sig, sizeof(HaveImage) - 1);
+	int no_image_header = !memcmp(NoImage, header->sig, sizeof(NoImage) - 1);
+
+	if (no_image_header)
+		return 0;
+
+	if (!have_image)
+		return -1;
+
+	if (header->resumed_before)
+		set_suspend_state(SUSPEND_RESUMED_BEFORE);
+	else
+		clear_suspend_state(SUSPEND_RESUMED_BEFORE);
+
+	target_header_start = header->first_header_block;
+	return 1;
+}
+

--
Nigel Cunningham		nigel at suspend2 dot net