Linux without initrd: unable to mount rootfs

## 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)