AnsweredAssumed Answered

earlycon on imx6sx Linux

Question asked by Eugen Warkentin on Apr 24, 2019
Latest reply on Apr 24, 2019 by Victor Linnik

I am trying to enable earlycon on imx6sx. I appended "earlycon=ec_imx21,0x02020000,1152008n" string to the kernel parameter passed from uboot to the kernel.  Indeed, this enabled the early console, but unfortunately, text output became garbled on my terminal:


setenv mmcargs setenv bootargs console=\${console},\${baudrate} root=/dev/mmcblk3p2 rootwait rw earlycon=ec_imx21,0x02020000,115200n8
=> saveenv
Saving Environment to MMC...
Writing to MMC(2)... done
=> boot
Kernel image @ 0x80800000 [ 0x000000 - 0x458180 ]
## Flattened Device Tree blob at 83000000
Booting using the fdt blob at 0x83000000
Using Device Tree in place at 83000000, end 8300f6fb
switch to ldo_bypass mode!


Starting kernel ...


Uncompressing Linux... done, booting the kernel.
[ 0.000000] Booting Linux on physical CPU 0x0
[ 0.000000] Linux version 4.9.88-rt66-gf5546cd-dirty (warkene@lbnidevlinux01) (gcc version 7.3.0 (GCC) ) #9 SMP PREEMPT RT Tue Apr 23 16:08:54 CDT 2019
[ 0.000000] CPU: ARMv7 Processor [412fc09a] revision 10 (ARMv7), cr=10c53c7d
[ 0.000000] CPU: PIPT / VIPT nonaliasing data cache, VIPT aliasing instruction cache
[ 0.000000] OF: fdt:Machine model: Freescale i.MX6 SoloX SDB RevB Board (Shure Blackhawk DSM eval)
[ 0.000000] earlycon: ec_imx21 at MMIO 0x02020000 (options '115200n8')
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[ 5.679913] console [ttymxc0] enabled
[ 5.684709] bootconsole [ec_imx21] disabled
[ 5.684709] bootconsole [ec_imx21] disabled
[ 5.709531] 21f4000.serial: ttymxc4 at MMIO 0x21f4000 (irq = 71, base_baud = 5000000) is a IMX
[ 5.752225] imx sema4 driver is registered.



It looks like baud rate was not set correctly?


Any help you can give will be greatly appreciated.



Eugen W.