Hi, i riddled over UEFI appendix A: > > Do you mean that one has to interpret the statement of UEFI 2.4 > > "All EFI GUIDs (Globally Unique Identifiers) have the format described > > in RFC 4122 [...] > > It should also be noted that TimeLow, TimeMid, TimeHighAndVersion fields > > in the EFI are encoded as little endian." > > as > > The text format of EFI GUIDs is the same as in RFC 4122, but the binary > > representation is byte-swapped at the first 4, 2, and 2 bytes.
Andrei Borzenkov wrote: > Yes. See other mail I just sent :) I have to give in, since i am not in the position to raise protest against Intel et.al. because of obfuscating english language. :)) > > Value "modification-date" produces a low > > quality GUID from the value set by option --modification-date=. > How? Time base UUID (Version 1) requires "node data" I am aware that the result is a poor fake of an UUID. Its time granularity is below any standard. No site id. So i let it pose as random. The reason for offering it is to reduce the number of parameters which one has to remember for reproducibly producing an ISO. (--modification-date= must be used in any case to override the automatic "now" timestamping of the ISO filesystem.) > > The partition GUIDs will be generated in a reproducible way by exoring a > > little-endian 32 bit counter with the disk GUID beginning at byte offset 9. > Not sure I follow - what counter? Partition number. I shall clarify this in the API. In result the GUID byte strings of a grub-mkrescue GPT will look like GPT disk GUID : 2303cd2a73c7424aa29825632da7f446 GPT partition GUID : 1 2303cd2a73c7424aa29925632da7f446 GPT partition GUID : 2 2303cd2a73c7424aa29a25632da7f446 GPT partition GUID : 3 2303cd2a73c7424aa29b25632da7f446 GPT partition GUID : 4 2303cd2a73c7424aa29c25632da7f446 In current xorriso, the first partition GUID is the original random and disk GUID is derived from it as last one: GPT disk GUID : 6d359a15f8763e47b9ee78207025c200 GPT partition GUID : 1 6d359a15f8763e47b9ea78207025c200 ... GPT partition GUID : 4 6d359a15f8763e47b9e978207025c200 > My copy of 2.4 RevC still does not mention IEEE 802 I have a PDF with title Unified Extensible Firmware Interface Specification Version 2.4 Errata B April, 2014 In appendix A, table 218, row "Node" i read: "Byte Offset: 10" "Byte Length: 6" "Description: The spatially unique node identifier. This can be based on any IEEE 802 address obtained from a network card. If no network card exists in the system, a cryptographic-quality random number can be used." > Yes it could be more clear. They should pay you a reward for compensating this flaw. Have a nice day :) Thomas _______________________________________________ Grub-devel mailing list Grub-devel@gnu.org https://lists.gnu.org/mailman/listinfo/grub-devel
