Could someone help me recovering my system after a BIOS disaster?

[Steeledpick]

@HardCode4All

[root@CachyOS liveuser]# cachy-chroot
Info: Found 7 block devices
Info: Found partition: Partition: /dev/sda1: FS: exfat UUID: F31D-4CE1
Info: Found partition: Partition: /dev/sda2: FS: vfat UUID: 3105-B091
Info: Found partition: Partition: /dev/sdb1: FS: vfat UUID: AA97-0100
Info: Found partition: Partition: /dev/nvme0n1p1: FS: vfat UUID: C817-5774
Info: Found partition: Partition: /dev/nvme0n1p3: FS: btrfs UUID: 0b4778d2-2b54-48a9-a184-b2a951e9335a
Info: Found partition: Partition: /dev/nvme0n1p4: FS: btrfs UUID: 8070f09c-85d9-4420-b00e-a941b3a85f83
Info: Found partition: Partition: /dev/nvme0n1p5: FS: btrfs UUID: ae032e5c-f8de-4f79-842b-280801eaa772
✔ Select the block device for the root partition (use arrow keys): · Partition: /dev/nvme0n1p3: FS: btrfs UUID: 0b4
778d2-2b54-48a9-a184-b2a951e9335a
Info: Selected BTRFS partition, mounting and listing subvolumes...
Info: Mounting partition /dev/nvme0n1p3 at /tmp/cachyos-chroot-temp-mount-0b4778d2-2b54-48a9-a184-b2a951e9335a-AmJPH
v with options: []
Info: Unmounting partition at /tmp/cachyos-chroot-temp-mount-0b4778d2-2b54-48a9-a184-b2a951e9335a-AmJPHv
✔ Do you want to use CachyOS BTRFS preset to auto mount root subvolume? · yes
Info: Mounting partition /dev/nvme0n1p3 at /tmp/cachyos-chroot-root-mount-0b4778d2-2b54-48a9-a184-b2a951e9335a-vWciU
q with options: ["-o", "subvolid=2297"]
Info: Mounting additional partitions based on /etc/fstab...
Info: Found 13 entries in /etc/fstab
Info: Mounting partition /dev/nvme0n1p1 at /tmp/cachyos-chroot-root-mount-0b4778d2-2b54-48a9-a184-b2a951e9335a-vWciU
q/boot with options: []
Warning: Partition already mounted: UUID=0b4778d2-2b54-48a9-a184-b2a951e9335a /, skipping...
Info: Mounting partition /dev/nvme0n1p3 at /tmp/cachyos-chroot-root-mount-0b4778d2-2b54-48a9-a184-b2a951e9335a-vWciU
q/root with options: ["-o", "subvolid=257"]
Info: Mounting partition /dev/nvme0n1p3 at /tmp/cachyos-chroot-root-mount-0b4778d2-2b54-48a9-a184-b2a951e9335a-vWciU
q/srv with options: ["-o", "subvolid=258"]
Info: Mounting partition /dev/nvme0n1p3 at /tmp/cachyos-chroot-root-mount-0b4778d2-2b54-48a9-a184-b2a951e9335a-vWciU
q/var/cache with options: ["-o", "subvolid=259"]
Info: Mounting partition /dev/nvme0n1p3 at /tmp/cachyos-chroot-root-mount-0b4778d2-2b54-48a9-a184-b2a951e9335a-vWciU
q/var/tmp with options: ["-o", "subvolid=260"]
Info: Mounting partition /dev/nvme0n1p3 at /tmp/cachyos-chroot-root-mount-0b4778d2-2b54-48a9-a184-b2a951e9335a-vWciU
q/var/log with options: ["-o", "subvolid=261"]
Info: Mounting partition /dev/nvme0n1p4 at /tmp/cachyos-chroot-temp-mount-8070f09c-85d9-4420-b00e-a941b3a85f83-Yhxo9
9 with options: []
Info: Unmounting partition at /tmp/cachyos-chroot-temp-mount-8070f09c-85d9-4420-b00e-a941b3a85f83-Yhxo99
Warning: No subvolume specified in fstab, using root subvolume
Info: Mounting partition /dev/nvme0n1p4 at /tmp/cachyos-chroot-root-mount-0b4778d2-2b54-48a9-a184-b2a951e9335a-vWciU
q/home with options: ["-o", "subvolid=5"]
Info: Mounting partition /dev/nvme0n1p5 at /tmp/cachyos-chroot-temp-mount-ae032e5c-f8de-4f79-842b-280801eaa772-m5dnk
g with options: []
Info: Unmounting partition at /tmp/cachyos-chroot-temp-mount-ae032e5c-f8de-4f79-842b-280801eaa772-m5dnkg
Warning: No subvolume specified in fstab, using root subvolume
Info: Mounting partition /dev/nvme0n1p5 at /tmp/cachyos-chroot-root-mount-0b4778d2-2b54-48a9-a184-b2a951e9335a-vWciU
q/apps with options: ["-o", "subvolid=5"]
Warning: Invalid fs_spec in fstab, skipping...
Warning: Device UUID=a75b588d-76cf-42e1-b8eb-d2069050cfcf not found, skipping mounting...
Warning: Device UUID=4c288d62-bc3c-428c-a1e9-cd1c3feebb0b not found, skipping mounting...
Info: Finished mounting additional partitions
? Do you want to mount additional partitions? (y/n) ›

Inside the Chroot

Ensure rEFInd is installed (it likely already is): pacman -Syu refind
Run the installer: refind-install
This is the simplest and most common usage. It will:
Detect your ESP (mounted at /boot in the chroot).
Copy rEFInd files to /boot/EFI/refind/ (or the standard location).
Install necessary filesystem drivers (based on your /boot filesystem).
Create or update the UEFI NVRAM boot entry using efibootmgr.

No options are usually needed for standard setups. when you bios update it wipes uefi nvram and this procedure should fix that.

Hopefully that will help