Arch Linux

cronoshot

Member

Registered: 2026-02-18

Posts: 3

EFI Shell> ls FS0: returns 0byte 0FIle 0Dir. hexedit shows FS0: corect

CONTEXT of the Problem
A: My UEFI is not recognizing my archlinux install EFI boot script (ESP) located on my NVMe partition 1 FAT32. The system has been working since may25. The last update I got was 11FEB26, the day (and one shutdown) before it failed. leading to the fail the system froze as well as the other tty# (ctrl+alt+F#). the kernel would respond with "this operation is disabled" in terminal just fine via the SysRq (alt+prntScrn+j). I restarted by holding down the power button.
B: I reset the UEFI, no fix. old BIOS compatibility is disabled.
C: The UEFI recognizes all disks(nvme boot, sataSSD storage, sataHDD storage) and boots from a 2026.02.01 archISO USB just fine. archRoot>efibootmgr will complete with no errors but the boot list remains unchanged showing 1 entry(archISO USB).
D: Shell>bcfg boot dump -v returns the archISO USB at FS1: (see Shell>map -b) as well as... 00000000: 00 00 42 4F                                                     *..BO*  i saw '*..BO*' in the archISO USB hexedit, i dont know what it or the other HEX means.
E: I am not sure how to proceed next, any insights? I hope this is a fun puzzle for us.

ROOT of the Problem
Using a archISO USB EFI shell...
shell>ls FS0: returns 0bytes 0FIles 0Dirs and no errors, AND Shell>vol FS0: returns "Cannot open file - 'fs0:\'" despite the following...

Shell>map -b returns...
FS1: Alias(s):HD1J0b:;BLK4:
   PciRoot(0x0)/Pci(0x1,0x3)/Pci(0x0,0x0)/USB(0x9,0x0)/HD(1,GPT,AB95D9<etc.>,0x800,0xE3D760)
FS0: Alias(s):HD0b:;BLK1:
   PciRoot(0x0)/Pci(0x1,0x1)/Pci(0x0,0x0)/NVMe(0x1,75-87-BE-<etc.>)/HD(1,GPT,871542<etc.>,0x800,0x200000)
The other drives and partitions are correctly recognized.

FS1: This is the archISO USB.
A:This is assessable with Shell>ls FS1: just fine.
B: It contains all expected files.
C: Hardware path matches my hardware layout.
D: archRoot>fsck.FAT shows no problems. E: archRoot>fdisk shows no problems.
F: Shell>hexedit -d fs1 0 512 shows the same as archRoot>xxd. (For reference: hexedit fs1=what to read, 0=start block, 512=num of blocks to read).
G: Shell>vol FS0: returns "Volume ARCH26FEB (rw)" etc. as expected.

FS0: The EFI knows this is FAT32 otherwise it would not assign FS0: to it, right?.
A: Inassessable with Shell>ls FS0:.
B: Using archISO USB It contains all expected files. like /EFI/BOOT/BOOTx64.efi,  /GRUB, amd-ucode.img, initramfs-linux.img, vmlinuz-linux
C: Hardware path matches my hardware layout.
D: archRoot>fsck.FAT shows no problems.
E: archRoot>fdisk shows no problems.
F: Using Shell>hexedit -d fs0 0 512 shows the same as archRoot>xxd.
G: Shell>vol FS0: returns "Cannot open file - 'fs0:\'"

HARDWARE of the Problem
CPU= AMD 5900X
RAM=32GB
mobo= ASRock.x470 Gaming K4
BIOS=ver.P4.40

Unrelated, Shell>smbiosview returns @ Type=40, Handle=0xE shows HEX as *.............MORDOR..* ||| do i have a sauron sized problem?

Last edited by cronoshot (2026-02-18 17:45:50)

mytArch

Member

Registered: 2024-11-16

Posts: 70

Re: EFI Shell> ls FS0: returns 0byte 0FIle 0Dir. hexedit shows FS0: corect

B: I reset the UEFI, no fix. old BIOS compatibility is disabled.

Previously UEFI boot?
If yes, you could try:
- boot to arch usb;
- mount efi system partition and root volume
- chroot
- (assuming your using GRUB) regenerate grub configuration and redeploy grub;
- exit from chroot and reboot

Good luck

Edit:
did you check through all the firmware defaults, e.g. has the reset turned secureboot on?

Last edited by mytArch (2026-02-19 01:12:04)