On 10/6/14, 7:32, "Mika Westerberg" [off-list ref]
wrote:

On Mon, Oct 06, 2014 at 02:50:21PM +0100, Grant Likely wrote:

quoted

quoted

+/* ACPI _DSD device properties UUID:

daffd814-6eba-4d8c-8a91-bc9bbf4aa301 */

quoted

+static const u8 prp_uuid[16] = {
+	0x14, 0xd8, 0xff, 0xda, 0xba, 0x6e, 0x8c, 0x4d,
+	0x8a, 0x91, 0xbc, 0x9b, 0xbf, 0x4a, 0xa3, 0x01
+};

?

What is the encoding used here? I see the first 4 bytes for "daffd814"
encoded in little endian (0x14 first), and then the remaining values
encoded in big-endian for each number. Is this typical for UUID values?

The buffer format is explained in ACPI 5.1 spec, page 823.

I generated the above so that I compiled a _DSD with correct UUID using
iASL and then disassambled it with the same tool.

I bugged Mika with the same question, it's a fairly non-intuitive encoding
:-)

-- 
Darren Hart
Intel Open Source Technology Center