Setting up serial interface via UART on Rockpro64

imtheone · 05-08-2022, 03:22 PM

Trying to go headless on my rockpro64 with serial interface for console. My setup on Minicom works great through the bootup processes but then freezes at "Starting kernel..." However, back on the tty1, the boot process continues without a snag and I land at a login prompt. Here is output of Minicom:

Welcome to minicom 2.7.1

OPTIONS: I18n
Compiled on May 6 2018, 08:02:47.
Port /dev/ttyUSB0, 12:40:24

Press CTRL-A Z for help on special keys

U-Boot TPL 2021.10 (Jan 20 2022 - 12:36:04)
Channel 0: LPDDR4, 50MHz
BW=32 Col=10 Bk=8 CS0 Row=16/15 CS=1 Die BW=16 Size=2048MB
Channel 1: LPDDR4, 50MHz
BW=32 Col=10 Bk=8 CS0 Row=16/15 CS=1 Die BW=16 Size=2048MB
256B stride
lpddr4_set_rate: change freq to 400000000 mhz 0, 1
lpddr4_set_rate: change freq to 800000000 mhz 1, 0
Trying to boot from BOOTROM
Returning to boot ROM...

U-Boot SPL 2021.10 (Jan 20 2022 - 12:36:04 +0000)
Trying to boot from SPI

U-Boot 2021.10 (Jan 20 2022 - 12:36:04 +0000) Slackware

SoC: Rockchip rk3399
Reset cause: POR
Model: Pine64 RockPro64 v2.1
DRAM: 3.9 GiB
PMIC: RK808
MMC: mmc@fe310000: 3, mmc@fe320000: 1, mmc@fe330000: 0
Loading Environment from SPIFlash... SF: Detected gd25q128 with page size 256 Bytes, erase size 4 KiB, total 16 MiB
*** Warning - bad CRC, using default environment

In: serial
Out: vidconsole
Err: vidconsole
Model: Pine64 RockPro64 v2.1
Net: eth0: ethernet@fe300000
Hit any key to stop autoboot: 0
switch to partitions #0, OK
mmc1 is current device
Scanning mmc 1:1...
Found /extlinux/extlinux.conf
Retrieving file: /extlinux/extlinux.conf
6572 bytes read in 7 ms (916 KiB/s)
1: Boot OS: Slackware Linux
Retrieving file: /initrd-armv8
270804168 bytes read in 11447 ms (22.6 MiB/s)
Retrieving file: /Image-armv8
27582976 bytes read in 1171 ms (22.5 MiB/s)
append: earlyprintk rootfstype=ext4 root=LABEL=SLKroot console=tty1
Retrieving file: /dtb/rockchip/rk3399-rockpro64.dtb
61678 bytes read in 11 ms (5.3 MiB/s)
Moving Image from 0x2080000 to 0x2200000, end=3cd0000
## Flattened Device Tree blob at 01f00000
Booting using the fdt blob at 0x1f00000
Loading Ramdisk to e1cdf000, end f1f214c8 ... OK
Loading Device Tree to 00000000e1ccc000, end 00000000e1cde0ed ... OK

Starting kernel ...

...and thats where it stops sending data. Without a cmdline.txt or config.txt file for configuration (like my rpi4b), I'm not sure how to reconfigure this to continue sending data up to the login prompt.

Thanks

imtheone · 05-12-2022, 10:34 PM

I was running the getty on ttyS0, kernel says:
[ 0.289838] ff180000.serial: ttyS0 at MMIO 0xff180000 (irq = 43, base_baud = 1500000) is a 16550A
[ 0.291046] ff1a0000.serial: ttyS2 at MMIO 0xff1a0000 (irq = 44, base_baud = 1500000) is a 16550A

so, I tried running the getty on ttyS2 and it worked flawlessly. Why S0 wouldn't work when the kernel says it was initialized, has me stumped though

VicFer · 05-12-2022, 11:24 PM

I think the problem is on your boot configuration:

Quote:

append: earlyprintk rootfstype=ext4 root=LABEL=SLKroot console=tty1

Maybe you need to change tty1 to whatever serial port you want to connect to.

Cheers

mralk3 · 05-13-2022, 03:38 AM

Remove "console=tty1" and the serial console will work again. On Rockchip console=tty1 sends all output to the attached display. There are some comments in /boot/extlinux/extlinux.conf explaining.

Quote:

# If you exclusively use the Linux Virtual Consoles (typically with an HDMI monitor or
# LCD panel), you may wish to direct all OS and Kernel output to it.
# You can set console=ttyX (for RK3399 it's tty1).
# However, this precludes the use of the UART ('Serial Console').
# If you want to be able to have console access on both the UART and Linux Virtual
# Console, omit the console= command line operator.