JetPack 4.2.1 Kernel boot output

With 4.2.1 the kernel output on the serial port is limited to :

Scanning mmc 1:1...
Found /boot/extlinux/extlinux.conf
Retrieving file: /boot/extlinux/extlinux.conf
733 bytes read in 72 ms (9.8 KiB/s)
L4T boot options
1:      primary kernel
Enter choice: 1:        primary kernel
Retrieving file: /boot/initrd
5562393 bytes read in 350 ms (15.2 MiB/s)
Retrieving file: /boot/Image
34179080 bytes read in 1542 ms (21.1 MiB/s)
append: tegraid= ddr_die=4096M@2048M section=512M memtype=0 vpr_resize usb_port_owner_info=0 lane_owner_info=0 emc_max_dvf
s=0 touch_id=0@63 video=tegrafb no_console_suspend=1 console=ttyS0,115200n8 debug_uartport=lsport,2 earlyprintk=uart8250-32bit,0x700
06000 maxcpus=4 usbcore.old_scheme_first=1 lp0_vec=0x1000@0xff780000 core_edp_mv=1075 core_edp_ma=4000  root=/dev/mmcblk0p1 rw rootw
ait rootfstype=ext4 console=ttyS0,115200n8 console=tty0 fbcon=map:0 net.ifnames=0    root=/dev/mmcblk0p1 rw rootwait rootfstype=ext4
 console=ttyS0,115200n8 console=tty0 fbcon=map:0 net.ifnames=0 quiet
## Flattened Device Tree blob at 83100000
   Booting using the fdt blob at 0x83100000
   reserving fdt memory region: addr=80000000 size=20000
   Using Device Tree in place at 0000000083100000, end 0000000083177282

Starting kernel ...

<hit enter to activate fiq debugger>
[    1.026073] tegradc tegradc.1: dpd enable lookup fail:-19
[    1.537576] Host read timeout at address 545c00c4
[    1.722924] imx219 6-0010: imx219_board_setup: error during i2c read probe (-121)
[    1.730518] imx219 6-0010: board setup failed
[    2.508346] cgroup: cgroup2: unknown option "nsdelegate"
[    3.916865] using random self ethernet address
[    3.921473] using random host ethernet address
[    3.968780] using random self ethernet address
[    3.976279] using random host ethernet address
[    4.091301] random: crng init done
[    4.094710] random: 7 urandom warning(s) missed due to ratelimiting
[    4.429835] tegra-xudc-new 700d0000.xudc: setup request failed: -95

Ubuntu 18.04.2 LTS jetson-desktop ttyS0

How to enable verbose output as per previous JetPack release?

Please remove the “quiet” in kernel cmdline in the “extlinux.conf”
-> /boot/extlinux/extlinux.conf

Thanks, also do you know if its possible with 4.2.1 to copy new compiled dtb files to the sd card instead of flashing through SDK manager?

Normally you have to reflash the dtb. scp would not work.

L4T documentation has some guidance for flashing. You could refer to it first.

Found in the file :

DEFAULT primary

MENU TITLE L4T boot options

LABEL primary
      MENU LABEL primary kernel
      LINUX /boot/Image
      INITRD /boot/initrd
      APPEND ${cbootargs} quiet

# When testing a custom kernel, it is recommended that you create a backup of
# the original kernel and add a new entry to this file so that the device can
# fallback to the original kernel. To do this:
# 1, Make a backup of the original kernel
#      sudo cp /boot/Image /boot/Image.backup
# 2, Copy your custom kernel into /boot/Image
# 3, Uncomment below menu setting lines for the original kernel
# 4, Reboot

# LABEL backup
#    MENU LABEL backup kernel
#    LINUX /boot/Image.backup
#    INITRD /boot/initrd
#    APPEND ${cbootargs}

The one after “APPEND” is the kernel command line. Sorry for my typo. It should be “quiet” lol…