### System details

Lenovo Thinkpad T14 Gen 1 AMD

### What's wrong?

## Summary

Omarchy fails to find its ArchISO boot device during early boot on a Lenovo ThinkPad T14.

The USB stick is readable by GRUB and GRUB successfully loads the kernel and initramfs. However, once Linux takes over, ArchISO cannot find the installation medium.

The reliable workaround is surprisingly simple: **immediately after GRUB has loaded the kernel/initramfs, unplug the USB stick and plug it back in.** If this is done early enough, Omarchy boots normally.

## Hardware / installation media

* Lenovo ThinkPad T14 Gen 1 AMD 
* Omarchy ISO built 2026-08-25
* USB stick: ~16 GB
* ISO flashed from Windows using balenaEtcher
* Internal drive: NVMe SSD
* UEFI boot

## Normal boot behavior

GRUB can read the USB stick without problems and loads:

```text
/arch/boot/x86_64/vmlinuz-linux-t2
/arch/boot/x86_64/initramfs-linux-t2.img
```

The normal Omarchy GRUB entry uses:

```text
archisobasedir=arch
archisosearchuuid=2026-08-25-11-17-12-00
xe.enable_panel_replay=0
initramfs_async=0
```

After removing `quiet splash`, the actual failure becomes visible:

```text
Waiting 10 seconds for device /dev/disk/by-uuid/2026-08-25-11-17-12-00 ...

Searching for '/boot/2026-08-25-11-17-12-00.uuid' in '/dev/nvme0n1p1'
Searching for '/boot/2026-08-25-11-17-12-00.uuid' in '/dev/nvme0n1p2'
Searching for '/boot/2026-08-25-11-17-12-00.uuid' in '/dev/nvme0n1p3'
Searching for '/boot/2026-08-25-11-17-12-00.uuid' in '/dev/nvme0n1p4'

ERROR: Device '2026-08-25-11-17-12-00' not found
```

It then drops into the initramfs/rootfs emergency shell.

## Interesting observation

Before replugging the USB stick, `/dev/sda` exists, but `blkid` does not identify an ISO filesystem on it and ArchISO does not find the expected UUID.

After unplugging and reconnecting the USB stick while Linux is running, the device is immediately detected correctly:

```text
sda      14.6G
├─sda1    5.8G
└─sda2     23M
```

`blkid` then reports:

```text
/dev/sda1:
UUID="2026-08-25-11-17-12-00"
LABEL="OMARCHY_202608"
TYPE="iso9660"
```

and:

```text
/dev/sda2:
LABEL="ARCHISO_EFI"
TYPE="vfat"
```

The ISO contents can then be mounted and read normally, including:

```text
/arch/x86_64/airootfs.sfs
/arch/x86_64/airootfs.sha512
/boot/2026-08-25-11-17-12-00.uuid
```

So the ISO itself appears intact and readable once the USB device has been reinitialized.

## Working workaround

The easiest workaround I found is:

1. Boot the Omarchy USB stick.
2. Let GRUB load the kernel and initramfs.
3. Immediately after leaving the bootloader, briefly unplug the USB stick.
4. Plug it back in before ArchISO finishes looking for its boot device.
5. ArchISO now sees `/dev/sda1` with the correct UUID and Omarchy continues booting.

This is reproducible.

Simply leaving the USB stick connected from GRUB through Linux startup causes the failure. I tried all available USB ports on the laptop, no change.

## Additional symptom

When the USB device is in the broken state, keyboard input in the initramfs emergency shell is also extremely sluggish and unreliable:

* key presses may take a long time to register
* some presses are lost
* holding a key slightly too long can produce duplicate characters
* even Enter can have a noticeable delay

This makes me wonder whether the issue is related to USB/xHCI initialization rather than specifically USB mass storage.

## Expected behavior

The USB device should remain usable when control passes from UEFI/GRUB to the Linux kernel, and ArchISO should find:

```text
/dev/disk/by-uuid/2026-08-25-11-17-12-00
```

without requiring a physical USB disconnect/reconnect.

## Actual behavior

GRUB can read the installation medium, but Linux initially does not expose the ISO filesystem/UUID correctly. Physically reconnecting the USB device causes it to become fully usable immediately.