[GH-ISSUE #1070] Flatcar PXE boot is broken in netboot.xyz #1828

New issue

Closed

opened 2026-03-01 18:36:42 +03:00 by kerem · 1 comment

kerem commented

2026-03-01 18:36:42 +03:00

Owner

Originally created by @jepio on GitHub (Feb 2, 2022).
Original GitHub issue: https://github.com/netbootxyz/netboot.xyz/issues/1070

Describe the bug

Flatcar PXE booting appears to not work correctly in netboot.xyz. Flatcar ships with an initramfs embedded in the kernel, and a second one that gets overlayed when pxe booting (the second one is passed through the usual iPXE protocol). This works in our testing when initrd=flatcar_production_pxe_image.cpio.gz is provided on the kernel command line. Since commit github.com/netbootxyz/netboot.xyz@efc9fa5dd1 (diff-d3aefe4b4c) an initrd=initrd.magic parameter is passed instead and this breaks boot, as the second initramfs is missing.

I tested with netboot.xyz 2.0.40, which didn't have that commit, and UEFI iPXE boot of Flatcar works correctly. BIOS iPXE boot doesn't work in netboot.xyz 2.0.40, so there appears to be a required iPXE fix since then (we test current iPXE builds directly in many environments and those work)

To Reproduce
Steps to reproduce the behavior:

fetch netboot.xyz.iso
boot in qemu qemu-system-x86_64 -enable-kvm -m 4096 -smp 2 -cdrom netboot.xyz.iso
"Linux Network Installs" -> "Container Linux by Flatcar" (btw. could we rename that to Flatcar Container Linux?) -> any channel
boot gets stuck at "A start job is running for /dev/disk/by-partlabel/USR-A (40s / 1min 30s)" which is a sign that the second initramfs is missing.

Expected behavior

Machine boots to login prompt.

Screenshots

Additional context

Originally created by @jepio on GitHub (Feb 2, 2022). Original GitHub issue: https://github.com/netbootxyz/netboot.xyz/issues/1070 **Describe the bug**  Flatcar PXE booting appears to not work correctly in netboot.xyz. Flatcar ships with an initramfs embedded in the kernel, and a second one that gets overlayed when pxe booting (the second one is passed through the usual iPXE protocol). This works in our testing when `initrd=flatcar_production_pxe_image.cpio.gz` is provided on the kernel command line. Since commit https://github.com/netbootxyz/netboot.xyz/commit/efc9fa5dd1db42bf6f3ebbfe54097729446d3a39#diff-d3aefe4b4c58d9e9d91f58b6fe4025dae8cd5578e0e9f0f944e109fbcbf6db19 an `initrd=initrd.magic` parameter is passed instead and this breaks boot, as the second initramfs is missing. I tested with netboot.xyz 2.0.40, which didn't have that commit, and UEFI iPXE boot of Flatcar works correctly. BIOS iPXE boot doesn't work in netboot.xyz 2.0.40, so there appears to be a required iPXE fix since then (we test current iPXE builds directly in many environments and those work) **To Reproduce** Steps to reproduce the behavior: 1. fetch netboot.xyz.iso 2. boot in qemu `qemu-system-x86_64 -enable-kvm -m 4096 -smp 2 -cdrom netboot.xyz.iso` 3. "Linux Network Installs" -> "Container Linux by Flatcar" (btw. could we rename that to Flatcar Container Linux?) -> any channel 4. boot gets stuck at "A start job is running for /dev/disk/by-partlabel/USR-A (40s / 1min 30s)" which is a sign that the second initramfs is missing. **Expected behavior**  Machine boots to login prompt. **Screenshots**  **Additional context**

kerem

2026-03-01 18:36:42 +03:00

closed this issue
added the
bug
label

kerem commented

2026-03-01 18:36:43 +03:00

Author

Owner

@holymoly commented on GitHub (Feb 25, 2022):

The commit solved the issue partly. When booting is using UEFI it works perfectly. When used in Bios mode there is still an error which also was discussed here https://github.com/flatcar-linux/Flatcar/issues/586#issuecomment-1041476482.
[ 0.932433] Initramfs unpacking failed: invalid magic at start of compressed archive

@holymoly commented on GitHub (Feb 25, 2022): The commit solved the issue partly. When booting is using UEFI it works perfectly. When used in Bios mode there is still an error which also was discussed here https://github.com/flatcar-linux/Flatcar/issues/586#issuecomment-1041476482. ` [ 0.932433] Initramfs unpacking failed: invalid magic at start of compressed archive `

No milestone

No project

No assignees

1 participant

Notifications

Due date

The due date is invalid or out of range. Please use the format "yyyy-mm-dd".

No due date set.

Dependencies

No dependencies set.

Reference

starred/netboot.xyz#1828

No description provided.

Rows
Columns