The problem appears to be in the following UEFI structures: typedef struct {
UINT8 Type; ///< 0x01 Hardware Device Path. ///< 0x02 ACPI Device Path. ///< 0x03 Messaging Device Path. ///< 0x04 Media Device Path. ///< 0x05 BIOS Boot Specification Device Path. ///< 0x7F End of Hardware Device Path. UINT8 SubType; ///< Varies by Type ///< 0xFF End Entire Device Path, or ///< 0x01 End This Instance of a Device Path and start a new ///< Device Path. UINT8 Length[2]; ///< Specific Device Path data. Type and Sub-Type define ///< type of data. Size of data is included in Length. } EFI_DEVICE_PATH_PROTOCOL; typedef struct { EFI_DEVICE_PATH_PROTOCOL Header; /// /// Describes the entry in a partition table, starting with entry 1. /// Partition number zero represents the entire device. Valid /// partition numbers for a MBR partition are [1, 4]. Valid /// partition numbers for a GPT partition are [1, NumberOfPartitionEntries]. /// UINT32 PartitionNumber; /// /// Starting LBA of the partition on the hard drive. /// UINT64 PartitionStart; /// /// Size of the partition in units of Logical Blocks. /// UINT64 PartitionSize; /// /// Signature unique to this partition: /// If SignatureType is 0, this field has to be initialized with 16 zeros. /// If SignatureType is 1, the MBR signature is stored in the first 4 bytes of this field. /// The other 12 bytes are initialized with zeros. /// If SignatureType is 2, this field contains a 16 byte signature. /// UINT8 Signature[16]; /// /// Partition Format: (Unused values reserved). /// 0x01 - PC-AT compatible legacy MBR. /// 0x02 - GUID Partition Table. /// UINT8 MBRType; /// /// Type of Disk Signature: (Unused values reserved). /// 0x00 - No Disk Signature. /// 0x01 - 32-bit signature from address 0x1b8 of the type 0x01 MBR. /// 0x02 - GUID signature. /// UINT8 SignatureType; } HARDDRIVE_DEVICE_PATH; It is our guess that HARDDRIVE_DEVICE_PATH is not packed in the Ubuntu source tree. Please confirm. Thanks, Abhishek -- You received this bug notification because you are a member of Ubuntu Bugs, which is subscribed to Ubuntu. https://bugs.launchpad.net/bugs/1272664 Title: Installing UEFI boot entry on Hyper-V gen 2 corrupts VM configuration, making the VM unuseable To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/efibootmgr/+bug/1272664/+subscriptions -- ubuntu-bugs mailing list ubuntu-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs