Now I will reboot. Wish me luck:
$ fatlabel /dev/nvme0n1p2 SYSTEMOLD
0x41: Dirty bit is set. Fs was not properly unmounted and some data may be corrupt.
Automatically removing dirty bit.
$ blkid
/dev/nvme0n1p1: LABEL="Windows RE tools" BLOCK_SIZE="512" UUID="3C7CF7997CF74C60" TYPE="ntfs" PARTLABEL="Basic data partition" PARTUUID="593e6f89-fa68-472f-85d7-b6fe1dbb2e56"
/dev/nvme0n1p2: LABEL_FATBOOT="SYSTEMOLD" LABEL="SYSTEMOLD" UUID="DCF7-772A" BLOCK_SIZE="512" TYPE="vfat" PARTLABEL="EFI System Partition" PARTUUID="2b95e4aa-736e-45a8-b654-9330261c002f"
/dev/nvme0n1p4: LABEL="Windows" BLOCK_SIZE="512" UUID="4E98FE2698FE0C69" TYPE="ntfs" PARTLABEL="Basic data partition" PARTUUID="916bd45a-eaf0-4a13-83a6-054828309907"
/dev/nvme0n1p5: LABEL="Dane" BLOCK_SIZE="512" UUID="CC242F3B242F2842" TYPE="ntfs" PARTLABEL="Basic data partition" PARTUUID="97257a5d-c2b0-48c7-a3f3-c1aa0da7076a"
/dev/nvme0n1p6: LABEL="nixos" UUID="a86a408b-2039-4002-bb13-ae15ae3d6d1a" BLOCK_SIZE="4096" TYPE="ext4" PARTUUID="a529a036-1e3c-4f5f-af32-6702890eb8b4"
/dev/nvme0n1p7: LABEL="debian" UUID="381b1f3e-67b9-46af-8ad9-dace488e197b" BLOCK_SIZE="4096" TYPE="ext4" PARTUUID="a141548b-5cb7-43e8-ac0a-08c149f18a10"
/dev/nvme0n1p8: LABEL_FATBOOT="SYSTEM" LABEL="SYSTEM" UUID="DCF7-772A" BLOCK_SIZE="512" TYPE="vfat" PARTLABEL="EFI System Partition" PARTUUID="2b95e4aa-736e-45a8-b654-9330261c002f"
/dev/nvme0n1p3: PARTLABEL="Microsoft reserved partition" PARTUUID="5d833726-0e87-430b-b015-dd511b387b19"
$ parted
GNU Parted 3.4
Using /dev/nvme0n1
Welcome to GNU Parted! Type 'help' to view a list of commands.
(parted) name 2 "EFI System Partition OLD"
(parted) quit
$ blkid
/dev/nvme0n1p1: LABEL="Windows RE tools" BLOCK_SIZE="512" UUID="3C7CF7997CF74C60" TYPE="ntfs" PARTLABEL="Basic data partition" PARTUUID="593e6f89-fa68-472f-85d7-b6fe1dbb2e56"
/dev/nvme0n1p2: LABEL_FATBOOT="SYSTEMOLD" LABEL="SYSTEMOLD" UUID="DCF7-772A" BLOCK_SIZE="512" TYPE="vfat" PARTLABEL="EFI System Partition OLD" PARTUUID="2b95e4aa-736e-45a8-b654-9330261c002f"
/dev/nvme0n1p4: LABEL="Windows" BLOCK_SIZE="512" UUID="4E98FE2698FE0C69" TYPE="ntfs" PARTLABEL="Basic data partition" PARTUUID="916bd45a-eaf0-4a13-83a6-054828309907"
/dev/nvme0n1p5: LABEL="Dane" BLOCK_SIZE="512" UUID="CC242F3B242F2842" TYPE="ntfs" PARTLABEL="Basic data partition" PARTUUID="97257a5d-c2b0-48c7-a3f3-c1aa0da7076a"
/dev/nvme0n1p6: LABEL="nixos" UUID="a86a408b-2039-4002-bb13-ae15ae3d6d1a" BLOCK_SIZE="4096" TYPE="ext4" PARTUUID="a529a036-1e3c-4f5f-af32-6702890eb8b4"
/dev/nvme0n1p7: LABEL="debian" UUID="381b1f3e-67b9-46af-8ad9-dace488e197b" BLOCK_SIZE="4096" TYPE="ext4" PARTUUID="a141548b-5cb7-43e8-ac0a-08c149f18a10"
/dev/nvme0n1p8: LABEL_FATBOOT="SYSTEM" LABEL="SYSTEM" UUID="DCF7-772A" BLOCK_SIZE="512" TYPE="vfat" PARTLABEL="EFI System Partition" PARTUUID="2b95e4aa-736e-45a8-b654-9330261c002f"
/dev/nvme0n1p3: PARTLABEL="Microsoft reserved partition" PARTUUID="5d833726-0e87-430b-b015-dd511b387b19"
$ gdisk /dev/nvme0n1
GPT fdisk (gdisk) version 1.0.7
Partition table scan:
MBR: protective
BSD: not present
APM: not present
GPT: present
Found valid GPT with protective MBR; using GPT.
Command (? for help): x
Expert command (? for help): c
Partition number (1-8): 2
Enter the partition's new unique GUID ('R' to randomize): R
New GUID is 4F264EA1-25E5-4309-98D9-79FF1DBE046D
Expert command (? for help): w
Final checks complete. About to write GPT data. THIS WILL OVERWRITE EXISTING
PARTITIONS!!
Do you want to proceed? (Y/N): y
OK; writing new GUID partition table (GPT) to /dev/nvme0n1.
Warning: The kernel is still using the old partition table.
The new table will be used at the next reboot or after you
run partprobe(8) or kpartx(8)
The operation has completed successfully.
$ blkid
/dev/nvme0n1p1: LABEL="Windows RE tools" BLOCK_SIZE="512" UUID="3C7CF7997CF74C60" TYPE="ntfs" PARTLABEL="Basic data partition" PARTUUID="593e6f89-fa68-472f-85d7-b6fe1dbb2e56"
/dev/nvme0n1p2: LABEL_FATBOOT="SYSTEMOLD" LABEL="SYSTEMOLD" UUID="DCF7-772A" BLOCK_SIZE="512" TYPE="vfat" PARTLABEL="EFI System Partition OLD" PARTUUID="4f264ea1-25e5-4309-98d9-79ff1dbe046d"
/dev/nvme0n1p4: LABEL="Windows" BLOCK_SIZE="512" UUID="4E98FE2698FE0C69" TYPE="ntfs" PARTLABEL="Basic data partition" PARTUUID="916bd45a-eaf0-4a13-83a6-054828309907"
/dev/nvme0n1p5: LABEL="Dane" BLOCK_SIZE="512" UUID="CC242F3B242F2842" TYPE="ntfs" PARTLABEL="Basic data partition" PARTUUID="97257a5d-c2b0-48c7-a3f3-c1aa0da7076a"
/dev/nvme0n1p6: LABEL="nixos" UUID="a86a408b-2039-4002-bb13-ae15ae3d6d1a" BLOCK_SIZE="4096" TYPE="ext4" PARTUUID="a529a036-1e3c-4f5f-af32-6702890eb8b4"
/dev/nvme0n1p7: LABEL="debian" UUID="381b1f3e-67b9-46af-8ad9-dace488e197b" BLOCK_SIZE="4096" TYPE="ext4" PARTUUID="a141548b-5cb7-43e8-ac0a-08c149f18a10"
/dev/nvme0n1p8: LABEL_FATBOOT="SYSTEM" LABEL="SYSTEM" UUID="DCF7-772A" BLOCK_SIZE="512" TYPE="vfat" PARTLABEL="EFI System Partition" PARTUUID="2b95e4aa-736e-45a8-b654-9330261c002f"
/dev/nvme0n1p3: PARTLABEL="Microsoft reserved partition" PARTUUID="5d833726-0e87-430b-b015-dd511b387b19"
$ umount /dev/nvme0n1p2
$ mkdosfs -i DCF7772B /dev/nvme0n1p2
mkfs.fat 4.1 (2017-01-24)
$ blkid
/dev/nvme0n1p1: LABEL="Windows RE tools" BLOCK_SIZE="512" UUID="3C7CF7997CF74C60" TYPE="ntfs" PARTLABEL="Basic data partition" PARTUUID="593e6f89-fa68-472f-85d7-b6fe1dbb2e56"
/dev/nvme0n1p2: SEC_TYPE="msdos" UUID="DCF7-772B" BLOCK_SIZE="512" TYPE="vfat" PARTLABEL="EFI System Partition OLD" PARTUUID="4f264ea1-25e5-4309-98d9-79ff1dbe046d"
/dev/nvme0n1p4: LABEL="Windows" BLOCK_SIZE="512" UUID="4E98FE2698FE0C69" TYPE="ntfs" PARTLABEL="Basic data partition" PARTUUID="916bd45a-eaf0-4a13-83a6-054828309907"
/dev/nvme0n1p5: LABEL="Dane" BLOCK_SIZE="512" UUID="CC242F3B242F2842" TYPE="ntfs" PARTLABEL="Basic data partition" PARTUUID="97257a5d-c2b0-48c7-a3f3-c1aa0da7076a"
/dev/nvme0n1p6: LABEL="nixos" UUID="a86a408b-2039-4002-bb13-ae15ae3d6d1a" BLOCK_SIZE="4096" TYPE="ext4" PARTUUID="a529a036-1e3c-4f5f-af32-6702890eb8b4"
/dev/nvme0n1p7: LABEL="debian" UUID="381b1f3e-67b9-46af-8ad9-dace488e197b" BLOCK_SIZE="4096" TYPE="ext4" PARTUUID="a141548b-5cb7-43e8-ac0a-08c149f18a10"
/dev/nvme0n1p8: LABEL_FATBOOT="SYSTEM" LABEL="SYSTEM" UUID="DCF7-772A" BLOCK_SIZE="512" TYPE="vfat" PARTLABEL="EFI System Partition" PARTUUID="2b95e4aa-736e-45a8-b654-9330261c002f"
/dev/nvme0n1p3: PARTLABEL="Microsoft reserved partition" PARTUUID="5d833726-0e87-430b-b015-dd511b387b19"
in hardware-configuraiton.nix I have this:
fileSystems."/boot" =
{ device = "/dev/disk/by-uuid/DCF7-772A";
fsType = "vfat";
};
so it should work.