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Diffstat (limited to 'Documentation/user/booting-linux.rst')
-rw-r--r-- | Documentation/user/booting-linux.rst | 14 |
1 files changed, 14 insertions, 0 deletions
diff --git a/Documentation/user/booting-linux.rst b/Documentation/user/booting-linux.rst index 98628faf9d..f26299efd9 100644 --- a/Documentation/user/booting-linux.rst +++ b/Documentation/user/booting-linux.rst @@ -99,6 +99,20 @@ with addpart to the Kernel: Kernel command line: mtdparts=physmap-flash.0:512k(bootloader),512k(env),4M(kernel),-(root); mxc_nand:1M(bootloader),1M(env),4M(kernel),-(root) +Creating root= options for the Kernel +^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ + +It's a common case that the Linux Kernel is loaded from a filesystem +that later becomes the root filesystem for the Kernel. For several +filesystems barebox can automatically append a suitable root= option +to the Kernel command line. This is done when ``global.bootm.appendroot`` +is true. How the root= option is appended depends on the device type +and filesystem the kernel is booted from. For disk like devices (SD/MMC, +ATA) the partition UUID will be used, the root= option will be something +like ``root=PARTUUID=deadbeef-1``. For UBIFS fileystems it will be +``root=ubi0:volname ubi.mtd=mtdpartname rootfstype=ubifs``. NFS +filesystems will result in ``root=/dev/nfs nfsroot=ip:/path/to/nfsroot,v3,tcp``. +The ``v3,tcp`` part is configurable in ``global.linux.rootnfsopts``. The boot command ---------------- |