MYiR MYD-JX8MX Series, Development Manual

Page: 23 / 31

4.7 UART test
Uart port test, here to modify the default debug uart port to test, the J18 is the default debug port output.
evk_8mq:/ # cat /proc/cmdline
console=ttymxc0,115200 earlycon=ec_imx6q,0x30860000,115200 init=/init androidboot.gui_resolution=1080p androidb
oot.console=ttymxc0 androidboot.hardware=freescale androidboot.fbTileSupport=enable cma=960M androidboot.primar
y_display=imx-drm firmware_class.path=/vendor/firmware transparent_hugepage=never androidboot.wificountrycode=C
N androidboot.wifivendor=rtk buildvariant=userdebug androidboot.serialno=0e1c09d6f060954c androidboot.btmacaddr
=0e:1c:09:d6:f0:60 androidboot.soc_type=imx8mq androidboot.storage_type=sd androidboot.boottime=1BLL:0,1BLE:662
8,KL:0,KD:0,AVB:4165,ODT:0,SW:0 androidboot.bootreason=cold,powerkey androidboot.verifiedbootstate=orange andro
idboot.slot_suffix=_a root=PARTUUID=1563086f-dbe4-469c-ad2f-7de87c9a3ff0 androidboot.vbmeta.device=PARTUUID=bd6
540bd-1b10-49c3-964c-3c34132c7d65 androidboot.vbmeta.avb_version=1.1 androidboot.vbmeta.device_state=unlocked a
ndroidboot.vbmeta.hash_alg=sha256 androidboot.vbmeta.size=3264 androidboot.vbmeta.digest=350fd45a58b5bb99a48a1c
30cf222138dcbc6a57b44767acfab0bef72bcdc616 androidboot.veritymode=disabled skip_initramfs rootwait androidboot.
dtbo_idx=0 androidboot.keystore=software
We can change console output by setting console=ttymxcx and androidboot.console=ttymxcx in uboot.
uart Note
ttymxc0 J18
ttymxc1 J19
ttymxc3 J21
For example set J21 as a debug uart port for testing, the steps are as follows.
1.boot up and press any key to enter uboot mode.
2.set the bootargs.
setenv bootargs 'console=ttymxc3,115200 earlycon=ec_imx6q,0x30860000,115200 init=/init androidboot.gui_resoluti
on=1080p androidboot.console=ttymxc3 androidboot.hardware=freescale androidboot.fbTileSupport=enable cma=960M a
ndroidboot.primary_display=imx-drm firmware_class.path=/vendor/firmware transparent_hugepage=never androidboot.
wificountrycode=CN androidboot.wifivendor=rtk buildvariant=userdebug androidboot.serialno=0e1c09d6f060954c andr
oidboot.btmacaddr=0e:1c:09:d6:f0:60 androidboot.soc_type=imx8mq androidboot.storage_type=sd androidboot.boottim
e=1BLL:0,1BLE:6628,KL:0,KD:0,AVB:4165,ODT:0,SW:0 androidboot.bootreason=cold,powerkey androidboot.verifiedboots
tate=orange androidboot.slot_suffix=_a root=PARTUUID=1563086f-dbe4-469c-ad2f-7de87c9a3ff0 androidboot.vbmeta.de
vice=PARTUUID=bd6540bd-1b10-49c3-964c-3c34132c7d65 androidboot.vbmeta.avb_version=1.1 androidboot.vbmeta.device
_state=unlocked androidboot.vbmeta.hash_alg=sha256 androidboot.vbmeta.size=3264 androidboot.vbmeta.digest=350fd
45a58b5bb99a48a1c30cf222138dcbc6a57b44767acfab0bef72bcdc616 androidboot.veritymode=disabled skip_initramfs root
wait androidboot.dtbo_idx=0 androidboot.keystore=software'
3.save
save
Restart again, you will find the debug info output from J21.
4.7 UART test
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