Also the installer should use FAT32 instead of FAT16 for EFI SYSTEM PARTITION as mandated by the UEFI Spec. FAT16 ESP partition is not recognised by Windows UEFI bootloader because of this.
The below quote is copied form the UEFI Specification 2.3.1 - Chapter 12.3 File System Format. [QUOTE] EFI encompasses the use of FAT32 for a system partition, and FAT12 or FAT16 for removable media. The FAT32 system partition is identified by an OSType value other than that used to identify previous versions of FAT. This unique partition type distinguishes an EFI defined file system from a normal FAT file system. The file system supported by EFI includes support for long file names. FAT defines that all files in a directory must have a unique name, and unique is defined as a case insensitive match. UEFI does not impose a restriction on the number or location of System Partitions that can exist on a system. System Partitions are discovered when required by UEFI firmware by examining the partition GUID and verifying that the contents of the partition conform to the FAT file system as defined in Section 12.3.1.1. Further, UEFI implementations may allow the use of conforming FAT partitions which do not use the ESP GUID. Partition creators may prevent UEFI firmware from examining and using a specific partition by setting bit 1 of the Partition Attributes (see 5.3.3) which will exclude the partition as a potential ESP. [/QUOTE] The installer should also reuse the existing filesystem if a valid FAT32 EFISYS partition is selected during installation instead simply formatting the partition to FAT16. ** Summary changed: - selecting efi partition overwrites windows bootloader + Installer should not format an existing EFI SYSTEM PARTITION and should use FAT32 instead of FAT16 as the FS -- You received this bug notification because you are a member of Ubuntu Bugs, which is subscribed to Ubuntu. https://bugs.launchpad.net/bugs/769669 Title: Installer should not format an existing EFI SYSTEM PARTITION and should use FAT32 instead of FAT16 as the FS To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/partman-efi/+bug/769669/+subscriptions -- ubuntu-bugs mailing list [email protected] https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs
