Attaching a bit more of the boot log.

HugeTLB registered 1.00 GiB page size, pre-allocated 0 pages
HugeTLB registered 32.0 MiB page size, pre-allocated 0 pages
HugeTLB registered 2.00 MiB page size, pre-allocated 0 pages
HugeTLB registered 64.0 KiB page size, pre-allocated 0 pages
iommu: Default domain type: Translated 
iommu: DMA domain TLB invalidation policy: strict mode 
SCSI subsystem initialized
EDAC MC: Ver: 3.0.0
clocksource: Switched to clocksource arch_sys_counter
workingset: timestamp_bits=62 max_order=19 bucket_order=0
Block layer SCSI generic (bsg) driver version 0.4 loaded (major 252)
io scheduler mq-deadline registered
cacheinfo: Unable to detect cache hierarchy for CPU 0
brd: module loaded
VFS: Mounted root (tmpfs filesystem) on device 0:15.
Freeing unused kernel memory: 704K
Run /init as init process
  with arguments:
    /init
  with environment:
    HOME=/
    TERM=linux
Kernel panic - not syncing: Requested init /init failed (error -2).
CPU: 0 PID: 1 Comm: swapper/0 Not tainted 5.15.0-rc7-00001-g8d7daa446b53-dirty #33
Call trace:
 dump_backtrace+0x0/0x1d0
 show_stack+0x14/0x20
 dump_stack_lvl+0x64/0x7c
 dump_stack+0x14/0x2c
 panic+0x158/0x304
 kernel_init+0xf0/0x150
 ret_from_fork+0x10/0x20
Kernel Offset: disabled
CPU features: 0x00001001,20000802
Memory Limit: none
---[ end Kernel panic - not syncing: Requested init /init failed (error -2). ]---

I am building an embedded linux OS for an experimental FPGA platform. I used upstream U-boot(boot-loader), linux(kernel) and buildroot(just for filesystem). I followed some examples and enabled the required initrd/initramfs support in my linux config.

CONFIG_BLK_DEV_INITRD=y
CONFIG_BLK_DEV_RAM=y
CONFIG_BLK_DEV_RAM_COUNT=1
CONFIG_BLK_DEV_RAM_SIZE=10240

I used the bootm command in u-boot to load a FIT image that comprises of the linux kernel, dtb and the rootfs.cpio(compiled from buildroot). Relevant info here:FIT_Test These are the bootargs passed to the kernel:

console=ttyS0,9600 earlyprintk maxcpus=1 earlycon root=/dev/ram init=/init rw rootfstype=tmpfs debug

**Note:** Couple of other things I tried , but resulted in the same error. - Passing the kernel,dtb and fs image separately. - Tried a basic initramfs with just an init script , simple directory structure and a separately compiled busybox placed in /bin/busybox with symbolic links. - Rather than passing an external FS, I passed the path to the initramfs source and compiled it into the kernel with CONFIG_INITRAMFS_SOURCE. I would appreciate any feedback/pointers on what I could be missing, been stuck on this for while now.

I have downloaded OpenWRT files for PC from OpenWRT site . I have installed DHCP and TFTP (in my LAN) and can boot (other) kernels from them. Now I want to boot these OpenWRT files. I wrote in PXE config DEFAULT minimallinux SAY Now booting Minimal Linux... LABEL minimallinux MENU LABEL Minimal Linux KERNEL vmlinuz INITRD rootfs-squashfs.img.gz It boots, loads kernel, then loads image, then starts boot printouts and finaly crashes with kernel panic and reboots VFS:Cannot open root device "(null)" or unknown-block(0,0): error-6 Please append a correct "root=" boot option; here are the available partitions: Kernel panic - not syncing: VFS: Unable to mount root fs on unknown un-blokc(0,0) I also tried KERNEL vmlinuz APPEND initrd=rootfs-squashfs.img.gz boot=live toram=rootfs-squashfs.img.gz and some other combinations but failed. Any hints appreciated :)

An embedded Linux device I am working with has the following kernel parameter: root=/dev/ram0 Additionally, the kernel image is bundled together with an initrd and device tree to make a *flattened image tree*, or FIT image. When fully booted the device does not have persistent storage. That is, anything written to the file system is completely volatile. Considering the root= parameter passed to the kernel, this is not surprising. My questions is: How does this work? - I do know that Uboot copies the kernel into ram and executes it with a bootm command, but where do the filesystem files come from? Are they contained within the initrd? My understanding of an initrd is that it is a temporary construct. If so, it would be an offset into FIT image blob. So, how is just passing root=/dev/ram0 sufficient for the kernel to know where its file system is? - Does the kernel perform introspection and read the FIT image's header to determine placement of constituent components? - How are file system changes supported inside a FIT image considering it will be packed together with both the kernel and device tree blob?

I'm facing an issue while booting a custom RHEL 8.10 ISO. During the boot process, I encounter the following error:

initqueue: /usr/sbin/fetch-kickstart-disk: line 24: rmdir: command not found

I extracted initrd.img, modified /usr/sbin/fetch-kickstart-disk, and then rebuilt the ISO. However, the problem persists. Has anyone encountered this issue before? Any suggestions on how to properly modify initrd.img or ensure rmdir is available during boot? Thanks This is what I tried: * Extract the image:

-sh
    xzcat initrd.img | cpio -idmv

* Modify line 24 to remove rmdir command:

-sh
    vi usr/sbin/fetch-kickstart-disk

* Recreate the image file

-sh
    find . | cpio -o -H newc | xz --check=crc32 -9 > /WORK/isolinux/initrd.img

* Build the ISO file

-sh
    xorriso -as mkisofs -o /RHEL-8-10-0-BaseOS-x86_64.iso -b isolinux/isolinux.bin -c isolinux/boot.cat -no-emul-boot -boot-load-size 4 -boot-info-table  /WORK/

First, the issue that I'm having is being unable to run VirtualBox on Kali 2.0. I set up a usb live with persistence running Kali 2.0, which at the time had the 4.6.0-kali1-amd64 kernel. I have since updated/upgraded/dist-upgraded etc with all of the recommended sources. As a part of this, the new headers/kernels that have been installed are 4.9.0-kali4-amd64. However, even after boot, the kernel is 4.6.0, as confirmed by uname -r and the error thrown by vbox. I know normally grub needs to be config'd, though there is no grub bootloader in the usb live boot. The error thrown by virtualbox says that no suitable driver was found for the 4.6.0 kernel, and also that the system is not set up to dynamically create drivers (though I believe that this is due to the fact that it is making the driver for the 4.9.0, but this is not the running kernel).

I want to boot a system with an initramfs that's the actual final filesystem, not a temporary initramfs for loading drivers. Unfortunately, Linux imposes different (and in my case, undesirable) behaviors when using initramfs, including at least the following differences: - devtmpfs is not auto-mounted, at least not at first, but seems to get auto-mounted at some point later which I can't figure out. - Instead of running /sbin/init (or the init program specified by init= on the command line) the kernel attempts to invoke /init. I know it's possible to work around these by putting some extra junk on the initramfs, but I'd rather it just behave like a normal root fs. Is there any way to achieve this? If I do need to work around it with userspace scripting in the initramfs, I at least want to understand what triggers the auto-mounting of devtmpfs.

I am trying to install CentOS 6 on new hardware for testing because our software is dependent on the package versions in CentOS 6. The trivial answer would be to update the software to run on a newer version since CentOS 6 is well past EOL, but I'm not a software dev and we will be looking at the LOE soon. The current state: - The machine has an Intel 13th gen i5-1335U processor with a UEFI only BIOS (no legacy mode) and secure boot disabled - CentOS 7.5+ and Debian 10.0+ works, but earlier versions do not - I am using x86_64 installers and burning them to removable media with Rufus in UEFI mode - I have verified that when installing they are using GPT partitions - The installers themselves will boot into GRUB (legacy or 2), but when it tries to load the kernel and initrd/initramfs it fails - Currently I have Debian 12 installed with CentOS 6 so Debian is controlling Grub 2, but it still won't boot into CentOS 6 -Older hardware which have legacy mode in their BIOS is able to use both MBR & GPT partitions and boot CentOS 6 (Intel Atom E3845) - I am able to virtulize RHEL 6 in Qemu running in Debian 12 Failed attempts to fix so far: - Recreated the RHEL 6 initramfs in Debian 12 - Modify the RHEL 6 GRUB 2 entry - Use the GRUB 2 OS prober to create a RHEL 6 entry - When loading an installer it either goes to a blinking cursor or the GRUB splash image is frozen on screen. In that state I am not able to switch to any TTYs - Adding echo statements to a custom GRUB entry makes it seem that it loads the initramfs. It shows the echo statements before loading the kernel, after loading the kernel but before loading initramfs, and after loading initramfs. After the echo statements show on screen it either reboots the machine or hangs with no TTYs. My current theories: - The kernels are not compiled with necessary modules/parameters - There is something with initrd/iniramfs which is preventing the kernel from booting - The intel microcode included with the installers does not support the newer processor - Even though secure boot has been disabled I need to install a self-signed MOK & shim Any ideas on why an older distro won't load on new hardware?

I'm trying to create a multiboot usb drive for Debian images including a live system, netinst, and DVD-1 iso. I've got as far as creating the partitions 1. EFI fat32 2. Boot luks2 3. ISOs luks2 Then I install grub targeting the efi and boot partitions, add a vmlinuz and initrd to the boot partition along with a custom grub.cfg. Grub successful unlocks the boot partition and then runs the kernel. However, at this point I can't get the kernel to unlock the ISOs partition where the iso images are. As far as I understand it, the initrd file downloaded from: https://deb.debian.org/debian/dists/bookworm/main/installer-amd64/current/images/hd-media/ does not include support for cryptsetup, nor does any other initrd image I've tried. It looks like I need to edit or make my own. My host system (also Debian) is able to unlock a luks partition so it is obviously possible, but I don't know the steps to take to set this up on a usb drive. My grub.cfg menuentries look a bit like:

# Workaround for "out of memory" error
rmmod tpm

menuentry "Install" {
   set isofile="/debian-${VERSION}-amd64-${installer}.iso"
   set options="cryptdevice=UUID=${cryptuuid}:luks root=/dev/mapper/luks quiet splash"
   linux /vmlinuz iso-scan/filename=$isofile $options
   initrd /initrd.img
}

menuentry "Live" {
    loopback loop ($root)$isofile
    linux (loop)/live/vmlinuz boot=live findiso=$isofile
    initrd (loop)/live/initrd.img
}

At the moment the iso-scan fails to find the iso image and it appears that the 3rd partition is never unlocked. I'm a little bit over my head with creating a custom initrd and am not sure where to start. A lot of the documentation assumes you are running commands on the local system for the local system. EDIT: I've had some success using debootstrap and then chroot, installing a few things and then using mkinitramfs, however it doesn't load properly > Gave up waiting for root file system device. Common problems: ... ALERT! /dev/mapper/luks does not exist. Dropping to a shell!

initramfs failed to do its job a few days ago and I've just noticed today that my boot partition was almost full because of useless initrd images. Is there a way of telling Debian to keep only two or three initrd images at most? I'm not sure that I have the same problem under Mobian which is derived from Debian. I'm under Debian 12 as far as I know.

I am trying to create a custom ramdisk, but it keeps failing right before launching init. Here is the script: https://gist.github.com/amanuel2/f3e8bb9399f3b3bd36a90cd925ecf63d Logs: Edit 2: Logs: https://pastebin.com/FUxUtiSE Script: https://gist.github.com/amanuel2/f3e8bb9399f3b3bd36a90cd925ecf63d

I have a laptop (with UEFI) that used to be able to boot from a usb stick, but can't any more. The problem started when I interrupted a fresh install of Devuan Live. The laptop has a non-removable mmcblk device and a removable (real) hard disk. Both have several linux kernels on them (Debian, Ubuntu). At power on I get the usual grub2 menu, but whatever I choose: it loads the kernel, then the initrd, but then nothing else happens. If I just load a kernel (no initrd) and boot, it starts booting but halts with a kernel panic (VFS syncing problem). memtest won't boot either. What could be the source of problem, and is there anything I could do to save the laptop? The only tool I have on the laptop itself is the grub2 console. Otherwise I could move the hard disk to another PC, put something on it, put it back in the laptop and try to get it booted.

in short, I was not satisfied with the available distros as they are either roo large or are missing the features I need ootb, I also want it to boot it into ramdisk, so I made my own ISO. This ISO contains the isolinux bootloader, the linux kernel and the initrd which contains busybox and a few other tools. Now the issue I'm having is that busybox init is trying to pivot_root and I haven't specified root, I also don't want to pivot as all I need is already in the ramdisk, however setting root=/dev/ram0 doesn't work(invalid partition/root) and it still causes a kernel panic Under "Operation" in this [link](https://www.kernel.org/doc/html/latest/admin-guide/initrd.html) I want to get to step 5 and no further, I haven't found much yet, so I am asking here. How would I prevent linux/busybox/init from trying to leave the ramdisk?

I use an initrd currently on an imx8 processor that uses buildroot for a base filesystem. (kernel is 5.10.52) For debugging purposes, I want to bypass the initrd and load the filesystem I copied to a real device partition (/dev/mmcblk2p2) -- so I pass: noinitrd root=/dev/mmcblk2p2 init=/linuxrc to the kernel command line. It gets completely ignored and boots /linuxrc that is in the initrd. console shows: Run /init as init process no matter what... and /proc/cmdline shows the parameters I pass in... Is noinitrd ignored? Are there any magic paramters that allow my system to boot off a physical partition with noinitrd specified?

I'm running Debian Bookworm on a TS412 (QNAP); it stores the kernel & initrd in flash. It has a total of 16MB of flash. So even after tweaking with the MD partitions the best I can get is a 12MB initrd . I'm using xz compression. But even so, the initial initrd was 12.5MB. I know the common fix is to reduce modules, but they are not the real issue.

2984    .../usr/lib/modules
6036    .../usr/share
18824   .../usr/lib/arm-linux-gnueabi

Looking in arm-linux-gnueabi it had stuff like libX11... This machine does not even have a console (even getting a serial line is difficult) it certainly does not need "X". So I removed lots of packages totally (apt-get remove ...) in fact rather more than I should really. But the result was a much smaller initrd (about 5MB IIRC) which boots and runs just fine. Problem is, if I ssh onto the box and run say emacs(1) it'd be nice to project the GUI version back to my normal desktop (which has lots of memory and big displays, etc.) but this would require installing the X client libraries on the TS412. Now I don't see why just because I have the package with the X client libraries installed, that a copy needs to be kept on initrd, they aren't needed during boot. Is there a way to limit other stuff from getting onto initrd, not just modules (which are not the culprit) I've already tried document searches for guides to limit initrd.

## Setup Partitions:

# fdisk -l /dev/sda
...
Device     Boot Start    End Sectors Size Id Type
/dev/sda1  *     2048  51199   49152  24M  c W95 FAT32 (LBA)
/dev/sda2       51200 204799  153600  75M 83 Linux

[Syslinux](https://wiki.archlinux.org/title/Syslinux) configuration:

UI menu.c32
LABEL linux
        LINUX ../bzImage
        APPEND nomodeset rootfstype=ext4 root=/dev/sda2

/init:

#!/bin/sh

mount -t proc proc proc
mount -t sysfs sysfs sys
mount -t devtmpfs udev dev

/bin/sh
poweroff -f

## Testing Booting via QEMU works:

# qemu-system-x86_64 /dev/sda

However, booting on my laptop gives:

Kernel panic - not syncing: VFS: Unable to mount root fs on unknown-block(0,0)

If I use an initrd:

...
APPEND nomodeset rootfstype=tmpfs initrd=../initrd.img

...then my laptop boots fine, despite the initrd not having any kernel modules ## See also - https://unix.stackexchange.com/questions/9451/booting-without-initrd - [Unable to mount...](https://unix.stackexchange.com/a/414662/450817)

I need advice if possible to load entire system into RAM. Let's imagine following situation: Booting LIVE OS from DVD and login as root lsblk shows

NAME   MAJ:MIN RM  SIZE RO TYPE MOUNTPOINTS
loop0    7:0    0  2.9G  1 loop 
sda      8:0    0 19.1G  0 disk 
|-sda1   8:1    0    1G  0 part 
`-sda2   8:2    0 18.1G  0 part 
sr0     11:0    1 1024M  0 rom

I cannot do netboot with ipxe because I will need to have VPN. The only option here is to use DD and overwrite existing /dev/sda with my custom alpine.img I will use qemu and apline linux virt image. Here are the steps I have done so far: - Booted Alpine linux from iso and created /dev/sda - sda will bave only boot partition as mounting point as following:

NAME   MAJ:MIN RM  SIZE RO TYPE MOUNTPOINTS
sda      8:0    0    1G  0 disk 
├─sda1   8:1    0  300M  0 part /boot

- in /boot directory I have copied following:

/boot/
├── alpine-rootfs.tar.gz
├── System.map-virt
├── boot -> .
├── config-virt
├── extlinux.conf
├── initramfs-virt
├── ldlinux.c32
├── ldlinux.sys
├── libcom32.c32
├── libutil.c32
├── lost+found
├── mboot.c32
├── menu.c32
├── vesamenu.c32
└── vmlinuz-virt

extlinux.conf contains

# Generated by update-extlinux 6.04_pre1-r15
DEFAULT menu.c32
PROMPT 0
MENU TITLE Alpine/Linux Boot Menu
MENU HIDDEN
MENU AUTOBOOT Alpine will be booted automatically in # seconds.
TIMEOUT 10
LABEL virt
  MENU LABEL Linux virt
  LINUX vmlinuz-virt
  INITRD initramfs-virt
  APPEND root=/dev/ram0 modules=sd-mod,usb-storage,ext4 quiet rootfstype=ext4

In the initramfs-virt I have added following code:

# Create a RAM disk with a filesystem (adjust the size as needed)
mkdir -p /sysroot
mount -t tmpfs -o size=512M tmpfs /sysroot
# Extract the contents of your root filesystem (e.g., Alpine Linux) to the RAM disk
tar -xzvf /path/to/your/alpine-rootfs.tar.gz -C /sysroot
# Pivot to the RAM disk as the new root filesystem
exec switch_root /sysroot /sbin/init

Unfortunately boot process fails, Can someone advice what am I doing wrong here The whole point here is to have following solution: - Once rescue DVD is booted use dd to overwrite existing /dev/sda with my custom alpine.img - next boot from custom alpine.img and load system into RAM - once you login to shell create ssh tunnelling and deploy final operating system

I have an issue when using an external NVME drive, grub successfully boots but once entering the entry default configuration (nixos generation) it gives me the below error: > "Timed out waiting for device /dev/dis/by-uuid/... to appear" I've double checked the UUID of the / partiton and it correctly matches what is in /etc/fstab and hardware-configuration.nix (which got generated with nixos-generate-config). In the grub recovery console if I do a ls -l I can see the partition with the correct UUID as well. I've also added "nvme" to boot.initrd.availableKernelModules. I'm able to nixos-enter the system via an external "live usb" with no issue. I suspect I need an additional initrd kernel module to be able to boot this, but I'm not sure which one? I've tried: 1. Adding these modules (got these from https://help.ubuntu.com/community/BootFromUSB) :

usbcore
sd_mod
ehci_hcd
uhci_hcd
ohci_hcd
usb_storage
scsi_mod

which still results in the same error. 2. Copying the partition to the internal drive (as opposed to the external NVME drive which still results in the same error.

After **update-initramfs -c -k KERNELVERSION**(I didn't do any change and just type this command), the initrd will always has different size with the previous initrd. And this situation happen on Debian 11 and Ubuntu 20.04. Does initrd has different compression method each time?

I am trying to learn stuff about initrd. I have followed this tutorial to build my own initrd from scratch, and I installed busybox on it. Then I made an .iso from it with isolinux, so I could test it in virtualbox. It works great! I have the basic commands from busybox, so I wanted to mount a filesystem. But the /dev directory is almost empty (no sda), except for some files I created while following the tutorial. I learned about udev and I think this is what I need. However I am not sure how to go on this. Should I just grab the latest source code from udev, compile it and add it to my initrd? And then call /bin/udev or something like that in my init script? Or is there an other/better way to populate the /dev directory? **Edit:** Some additional info and updates on what I have done already. - I test everything in virtual box. I just installed ubuntu minimal in virtual box, made an .iso from my initrd, and then boot from the iso in virtualbox. - I used the vmlinuz and /lib/modules that were present on a debian-businesscard.iso and copied those over to my initrd which I created by following the tutorial I linked earlier. - Kernel has CONFIG_DEVTMPFS=y - Some devices show up in /dev, like tty0-tty63 and some others, but no sda/hda. - Ran lspci -k in my currently running OS and in a virtual box to check which modules are in use. SATA Controller says it uses ahci as module. - When I execute modprobe -v ahci it complains a lot about "unknown symbol: ata_some_stuff", but after that it returns something like SCSI Subsystem initialized, ATA-6: VBOX HARDDISK and Direct-Access ATA VBOX HARDDISK. However, still no harddrive devices found in /dev. My current /init/ script is as follows: #!/bin/ash mount -t devtmpfs none /dev mount -t proc /proc /proc mount -t sysfs none /sys modprobe -v ahci echo "Hello world" exec /bin/ash --login Does anyone has any idea what I am doing wrong and what I should be doing instead?

I have been trying to load an updated initrd.img file with updated drivers on booting the Centos 7.6 ISO, however it seems to still load the old driver even though I have replaced the driver. ##Steps taken:## ###Extracted initrd image from ISO:### 1. Mounted CentOS 7.6 ISO 2. Copied the initrd.img from isolinux/initrd.img to temporary folder (/tmp/image) 3. Created a new folder at /tmp/image/initrd 4. Extracted the initrd.img the folder by running

xz -dc /dev/null | cpio -c -o | xz -9 --check=crc32 > ../initrd.img

3. Copy the generated initrd.img back into the ISO at isolinux/initrd.img and images/pxe/initrd.img ##Expected Results## After updating the driver in the initrd.img and copying it into the ISO, I expect the new driver (e1000e version 3.6.0) to be loaded in after the ISO install boot process is complete. ##Actual Results## I am able to boot from the ISO and install Centos 7 from it, however after installing Centos, running the following command:

modinfo e1000e

Gives the old version of the driver that was on the initrd.img initially (e1000e version 3.2.6) rather than version 3.6.0 which I loaded onto the initrd.img image. I am not too sure what I am doing wrong, whether I am creating the driver incorrectly, loading the driver incorrectly, creating the initrd.img incorrectly or anything else. Any help would be appreciated as I have been trying to get this working for the past few days. This is my first post, so let me know if I am doing anything wrong or if any additional information is required debug this issue. Cheers