3rd-party/linux-kernel-module-cheat
1
0
Fork 0
mirror of https://github.com/cirosantilli/linux-kernel-module-cheat.git synced 2026-01-23 02:05:57 +01:00
Code Issues Releases Wiki Activity

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

Browse Source
This commit is contained in:
Ciro Santilli 六四事件 法轮功
2019-12-10 00:00:00 +00:00
parent 6d0a900f4c
commit 50ac89b779
2 changed files with 25 additions and 0 deletions
Download Patch File Download Diff File Expand all files Collapse all files

23
README.adoc
View File

@@ -6646,6 +6646,29 @@ Source: link:kernel_modules/warn_on.c[]
Can also be activated with the `panic_on_warn` boot parameter. Can also be activated with the `panic_on_warn` boot parameter.
[[not-syncing]]
==== not syncing: VFS: Unable to mount root fs on unknown-block(0,0)
Let's learn how to diagnose problems with the root filesystem not being found. TODO add a sample panic error message for each error type:
* https://askubuntu.com/questions/41930/kernel-panic-not-syncing-vfs-unable-to-mount-root-fs-on-unknown-block0-0/1048477#1048477
This is the diagnosis procedure:
* does the filesystem appear on the list of filesystems? If not, then likely you are missing either:
** the driver for that hardware type, e.g. hard drive / SSD type. Here, Linux does not know how to communicate with a given hardware to get bytes from it at all. In simiulation, the most important often missing one is virtio which needs:
+
....
CONFIG_VIRTIO_PCI=y
CONFIG_VIRTIO_BLK=y
....
** the driver for that filesystem type. Here, Linux can read bytes from the hardware, but cannot interpret them as a tree of files because it does not recognize the file system format. For example, to boot from <<squashfs>> we would need:
+
....
CONFIG_SQUASHFS=y
....
* your filesystem of interest appears in the list, then you just need to set the `root` <<kernel-command-line-parameters,command line parameter>> to point to that, e.g. `root=/dev/sda`
=== Pseudo filesystems === Pseudo filesystems
Pseudo filesystems are filesystems that don't represent actual files in a hard disk, but rather allow us to do special operations on filesystem-related system calls. Pseudo filesystems are filesystems that don't represent actual files in a hard disk, but rather allow us to do special operations on filesystem-related system calls.

2
linux_config/default
View File

@@ -7,6 +7,7 @@ CONFIG_MODULE_SRCVERSION_ALL=y
# Filesystems. # Filesystems.
CONFIG_DEBUG_FS=y CONFIG_DEBUG_FS=y
CONFIG_OVERLAY_FS=y CONFIG_OVERLAY_FS=y
# https://cirosantilli.com/linux-kernel-module-cheat#squashfs
CONFIG_SQUASHFS=y CONFIG_SQUASHFS=y
# GDB debugging. # GDB debugging.
@@ -77,6 +78,7 @@ CONFIG_NET_9P_VIRTIO=y
CONFIG_PCI=y CONFIG_PCI=y
CONFIG_PCI_HOST_COMMON=y CONFIG_PCI_HOST_COMMON=y
CONFIG_PCI_HOST_GENERIC=y CONFIG_PCI_HOST_GENERIC=y
# https://cirosantilli.com/linux-kernel-module-cheat#not-syncing
CONFIG_VIRTIO_PCI=y CONFIG_VIRTIO_PCI=y
CONFIG_VIRTIO_BLK=y CONFIG_VIRTIO_BLK=y