3 ms·

Does it? On my Windows 11 install, the EFI partition is still FAT32. There are no other partitions than the C and the recovery partition. Am I missing somethin

Does it? On my Windows 11 install, the EFI partition is still FAT32. There are no other partitions than the C and the recovery partition. Am I missing something?

CameronNemo 4y ago
The commenter is saying that there is an NTFS boot partition that is chained after the ESP. So UEFI mounts and execs whatever is in the (vFAT) ESP, and then that ESP bootloader loads data from the (NTFS) boot partition.
- vetinari 4y ago
  MSR (that another partition) has no role in Windows boot. Windows will work without it being present at all.
p_l 4y ago
Windows has been setting up Reserved partitions with boot code for some time now - even (or especially) on systems without EFI
- deathanatos 4y ago
  The OP is about a separate boot partition, which is normally where the kernel and associated data (on Linux, an initramfs, obviously Windows would differ a bit). The "Reserved" partition on Windows machines isn't really a boot partition, for any meaningful definition of it. It's just … reserved, and MS being MS. On my machine, it's empty (unformatted, all 0s). It is lightly documented here: https://learn.microsoft.com/en-us/windows-hardware/manufacture/desktop/configure-uefigpt-based-hard-drive-partitions?view=windows-11#microsoft-reserved-partition-msr https://learn.microsoft.com/en-us/windows-hardware/manufactu... (I'd expect your typical GPT Windows install to have about four partitions: the ESP, the empty "reserved" partition, a recovery partition, and the main NTFS partition.)
  - cesarb 4y ago
    > The "Reserved" partition on Windows machines isn't really a boot partition, for any meaningful definition of it. It's just … reserved, and MS being MS. On my machine, it's empty (unformatted, all 0s). It is lightly documented here: https://learn.microsoft.com/en-us/windows-hardware/manufacture/desktop/configure-uefigpt-based-hard-drive-partitions?view=windows-11#microsoft-reserved-partition-msr https://learn.microsoft.com/en-us/windows-hardware/manufactu... IIRC, that "reserved" partition is to allow converting the data partition which follows it to a "dynamic disk" (which AFAIK, is Microsoft's equivalent to a Linux LVM PV). That conversion needs to grow the partition backwards to prepend some headers, and that extra space comes from shrinking the reserved partition just before it.
  - p_l 4y ago
    On various BIOS-based systems, the reserved partition would contain files necessary for booting windows from its system volume, bridging the gap between what could be accessed by simplistic MBR boot code, the NTFS boot code block, and the NTFS-understanding, ARC emulating (for NT5) or EFI-emulating (NT6) boot system that would load target system. Details on whether reserved partition would be created and what would be on it depend on hardware you're installing on, and if separate boot partition is necessary windows installer would inform you about need to create an extra partition.

Does it? On my Windows 11 install, the EFI partition is still FAT32. There are no other partitions than the C and the recovery partition. Am I missing something?

CameronNemo 4y ago

The commenter is saying that there is an NTFS boot partition that is chained after the ESP. So UEFI mounts and execs whatever is in the (vFAT) ESP, and then that ESP bootloader loads data from the (NTFS) boot partition.

vetinari 4y ago
MSR (that another partition) has no role in Windows boot. Windows will work without it being present at all.

p_l 4y ago

Windows has been setting up Reserved partitions with boot code for some time now - even (or especially) on systems without EFI

deathanatos 4y ago
The OP is about a separate boot partition, which is normally where the kernel and associated data (on Linux, an initramfs, obviously Windows would differ a bit). The "Reserved" partition on Windows machines isn't really a boot partition, for any meaningful definition of it. It's just … reserved, and MS being MS. On my machine, it's empty (unformatted, all 0s). It is lightly documented here: https://learn.microsoft.com/en-us/windows-hardware/manufacture/desktop/configure-uefigpt-based-hard-drive-partitions?view=windows-11#microsoft-reserved-partition-msr https://learn.microsoft.com/en-us/windows-hardware/manufactu... (I'd expect your typical GPT Windows install to have about four partitions: the ESP, the empty "reserved" partition, a recovery partition, and the main NTFS partition.)
- cesarb 4y ago
  > The "Reserved" partition on Windows machines isn't really a boot partition, for any meaningful definition of it. It's just … reserved, and MS being MS. On my machine, it's empty (unformatted, all 0s). It is lightly documented here: https://learn.microsoft.com/en-us/windows-hardware/manufacture/desktop/configure-uefigpt-based-hard-drive-partitions?view=windows-11#microsoft-reserved-partition-msr https://learn.microsoft.com/en-us/windows-hardware/manufactu... IIRC, that "reserved" partition is to allow converting the data partition which follows it to a "dynamic disk" (which AFAIK, is Microsoft's equivalent to a Linux LVM PV). That conversion needs to grow the partition backwards to prepend some headers, and that extra space comes from shrinking the reserved partition just before it.
- p_l 4y ago
  On various BIOS-based systems, the reserved partition would contain files necessary for booting windows from its system volume, bridging the gap between what could be accessed by simplistic MBR boot code, the NTFS boot code block, and the NTFS-understanding, ARC emulating (for NT5) or EFI-emulating (NT6) boot system that would load target system. Details on whether reserved partition would be created and what would be on it depend on hardware you're installing on, and if separate boot partition is necessary windows installer would inform you about need to create an extra partition.