The “Warning: unable to open an initial console” on a 2.2 kernel usually means the kernel (or init) can’t open /dev/console (or a fallback tty) from whatever root filesystem it mounted first (your real root or your initrd). That’s almost always due to:
/dev/console missing or wrong type/major/minor,
console support not enabled in the kernel (virtual terminal/serial),
mounting a root/initrd whose /dev is empty/minimal,
wrong permissions/ownership on console devices,
booting with serial console without the right devices or kernel config.
You don’t need to “point LILO to a dev image” directly; if you use an initrd, you specify it with initrd=..., and that initrd must contain a proper /dev (including /dev/console). If you boot straight to the disk’s root fs, that /dev must be correct.
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Verify your essential device nodes (on the root filesystem the 2.2 kernel will mount)
Boot the working 2.0 kernel. Then check and (re)create the must-have character devices:
Code:
# As root, on your *real* root filesystem (not a chroot, not a tmpfs):
ls -l /dev/console /dev/tty /dev/tty0 /dev/null /dev/zero /dev/ptmx || true
# Create/repair them if missing or wrong. The major/minor values are the classic ones:
# /dev/console -> c 5,1 (permissions usually 0600 root:root)
# /dev/tty -> c 5,0 (0666)
# /dev/tty0 -> c 4,0 (0666) (VGA console first VT)
# /dev/null -> c 1,3 (0666)
# /dev/zero -> c 1,5 (0666)
# /dev/ptmx -> c 5,2 (0666) (ptmx for devpts, optional but helpful)
# Recreate with canonical modes:
mknod -m 600 /dev/console c 5 1
mknod -m 666 /dev/tty c 5 0
mknod -m 666 /dev/tty0 c 4 0
mknod -m 666 /dev/null c 1 3
mknod -m 666 /dev/zero c 1 5
mknod -m 666 /dev/ptmx c 5 2
chown root:root /dev/console /dev/tty /dev/tty0 /dev/null /dev/zero /dev/ptmx
The majors/minors did not change between 2.0 and 2.2 for these core devices; 2.2 is simply stricter about them being present and usable.
If you plan to use serial console, also make sure your serial devices exist
Code:
# Standard PC COM ports
mknod -m 660 /dev/ttyS0 c 4 64
mknod -m 660 /dev/ttyS1 c 4 65
chown root:uucp /dev/ttyS0 /dev/ttyS1 # or root:dialout depending on your system
``
Kernel config: enable console support that matches how you want to see output
Rebuild your 2.2 kernel with:
Built-in (not modules) for whatever is needed to get to the root fs.
Storage (IDE/SCSI driver for your disk controller) - ** NOTE - 2.x kernels do not support SSD/NVME drives. You will need an older drive.
Filesystem (likely ext2)
Console/VT support:
CONFIG_VT=y
CONFIG_VGA_CONSOLE=y (if using VGA text console)
CONFIG_SERIAL=y and CONFIG_SERIAL_CONSOLE=y (if using serial console)
Optional: CONFIG_UNIX98_PTYS=y and CONFIG_DEVPTS_FS=y if you want /dev/pts behavior. If you enable devpts, consider adding a mount in rc.sysinit:
Code:
mount -t devpts devpts /dev/pts
If you intend to use serial console,
Code:
append="console=ttyS0,115200n8"
Red Hat 5.2 used an initrd to preload SCSI/IDE modules for the root disk. If your 2.2 kernel has all storage + filesystem needed built-in, you can boot without an initrd. If you do use an initrd:
Build an initrd that includes:
Required storage modules
linuxrc or init script
A minimal /dev containing at least /dev/console, /dev/tty, /dev/null, etc.
Point LILO to it:
Code:
image=/boot/vmlinuz-2.2.x
label=linux-2.2
root=/dev/hda2 # adjust to your actual root
read-only
initrd=/boot/initrd-2.2.x.img
append="...optional console=... if serial..."
Make sure /sbin/init exists and is executable. If debugging, you can try:
Root FS driver must be built-in, not a module; otherwise the kernel can’t mount root, and you’ll fall back to the initrd and hit /dev issues.
If you see the console warning and other messages about “Trying to execute init” or “No init found”, confirm the path to /sbin/init and that your root device in LILO (root=/dev/…) is correct.
Make sure /dev is the real directory on your root (not a stale mount or mis-specified chroot when you created nodes).
Permissions: /dev/console typically 0600 root:root. Some init setups prefer 0600; others tolerate 0600/0620/0666. If paranoid, try 0660 root:tty and ensure init can open it.
You will need (at the very least) these devices.
Code:
# Core
mknod -m 600 /dev/console c 5 1
mknod -m 666 /dev/tty c 5 0
mknod -m 666 /dev/tty0 c 4 0
mknod -m 666 /dev/null c 1 3
mknod -m 666 /dev/zero c 1 5
mknod -m 666 /dev/ptmx c 5 2
# Optional for ttys
for i in 1 2 3 4 5 6; do mknod -m 620 /dev/tty$i c 4 $i; done
# Serial (as needed)
mknod -m 660 /dev/ttyS0 c 4 64
mknod -m 660 /dev/ttyS1 c 4 65
Here is an example LILO I have used before.
Code:
image=/boot/vmlinuz-2.2.26 # adjust name
label=linux-2.2
root=/dev/hda2 # your root
read-only
append="console=tty0" # or omit; or use console=ttyS0,115200
Given RH 5.2’s age, the most likely fix is:
Recreate /dev/console et al. on the root filesystem you’re booting with 2.2.
Ensure the 2.2 kernel has VT/VGA console (or serial console) enabled.
If you use an initrd, ensure it contains the device nodes (or remove the need for initrd by compiling drivers in).
You probably do not need different major/minor numbers for 2.2; you just need the correct classic ones present and accessible.
...as you can see, this is not a trival project.
How are you planning to console—VGA or serial? And are you building your storage + ext2 built-in or relying on modules/initrd?
, but there may be a limit to one's patience, especially if one enters into a "dependency hell".
