Hardware Reference
In-Depth Information
Figure 6-3:
he cmdline
.txt ile in
/boot
In a Linux-based desktop or laptop, these options are normally passed to the kernel by a tool
known as a
bootloader
, which has its own coniguration ile. On the Pi, the options are simply
entered directly into
cmdline.txt
to be read by the Pi at startup.
Almost any kernel option supported by Linux can be entered into the
cmdline.txt
ile, to
alter things like the appearance of the console or which kernel is loaded. As an example, here
is the
cmdline.txt
ile from the Debian distribution, which should be written in the ile as
one continuous line:
dwc_otg.lpm_enable=0 console=ttyAMA0,115200 Æ
kgdboc=ttyAMA0,115200 console=tty1 root=/dev/mmcblk0p2 Æ
rootfstype=ext4 rootwait
he irst option,
dwg_otc.lpm_enable
, tells the Pi to disable the
On-he-Go (OTG)
mode
of its USB controller, to prevent problems that can occur when the functionality is enabled
without proper support in the operating system. he majority of Linux distributions for the
Pi disable this mode.
