6.2.2 Kernel command line (bootargs)
Depending on the different booting/usage scenarios, you may need different kernel boot parameters set for bootargs.
Table 14. Kernel boot parameters
Kernel parameter
Description
Typical value
Used when
console
Where to output
kernel log by
printk.
console=ttymxc0
i.MX 8M Nano EVK use console=ttymxc1
init
Tells kernel where
the init file is
located.
init=/init
All use cases. "init" in the Android platform
is located in "/" instead of in "/sbin".
androidboot.console
The Android shell
console. It should
be the same as
console=.
androidboot.console=ttymxc0
To use the default shell job control, such as
Ctrl+C to terminate a running process, set
this for the kernel.
cma
CMA memory
size for GPU/VPU
physical memory
allocation.
• For i.MX 8M Nano EVK, it
is 800 MB by default.
• For i.MX 8QuadXPlus, it is
800 MB by default.
For i.MX 8QuadXPlus MEK, the start
address is 0x96000000 and end address is
0xDFFFFFFFF. The CMA size can be
configured to other value, but cannot be
large than 1184 MB as teh Cortex-M4 core
will also allocate memory from CMA and
Cortex-M4 cannot use the memory large
than 0xDFFFFFFFF.
androidboot.selinux
Argument to
disable selinux
check and enable
serial input when
connecting a host
computer to the
target board’s
USB UART port.
For details about
selinux, see
Security-
Enhanced Linux
in Android
androidboot.selinux=permissiv
e
Android Pie 9.0 CTS requirement: serial
input should be disabled by default.
Setting this argument enables console serial
input, which will violate the CTS
requirement.
Setting this argument will also bypass all the
selinux rules defined in Android system. It is
recommended to set this argument for
internal developer.
androidboot.primary_displa
y
It is used to chose
and fix primary
display.
androidboot.primary_display=i
mx-drm
androidboot.primary_display=mxsfb-drm is
only used for MIPI display.
androidboot.lcd_density
It is used to set
the display
density and over
write
ro.sf.lcd_density
in init.rc for MIPI-
to-HDMI display.
androidboot.lcd_density=160
-
Table continues on the next page...
NXP Semiconductors
Booting
Android
™
User's Guide, Rev. P9.0.0_2.3.2, 6 March 2020
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