En ouvrant le MK20 on trouve 6 pads sur le coté dont un semble correspondre à l’UART de boot du T113-S3.

Si on branche un adaptateur USB-UART dessus on obtient la sortie suivante :
$ tio -b 115200 /dev/ttyUSB0
[tio 22:20:30] tio v1.32
[tio 22:20:30] Press ctrl-t q to quit
[tio 22:20:30] Connected
[192]HELLO! BOOT0 is starting!
[195]BOOT0 commit : 4d16602
[198]set pll start
[200]fix vccio detect value:0xc0
[207]periph0 has been enabled
[210]set pll end
[211][pmu]: bus read error
[214]board init ok
[216]ZQ value = 0x2d
[218]get_pmu_exist() = -1
[221]ddr_efuse_type: 0xa
[223]trefi:7.8ms
[225][AUTO DEBUG] single rank and full DQ!
[230]ddr_efuse_type: 0xa
[232]trefi:7.8ms
[234][AUTO DEBUG] rank 0 row = 13
[238][AUTO DEBUG] rank 0 bank = 8
[241][AUTO DEBUG] rank 0 page size = 2 KB
[245]DRAM BOOT DRIVE INFO: V0.33
[248]DRAM CLK = 792 MHz
[250]DRAM Type = 3 (2:DDR2,3:DDR3)
[253]DRAMC read ODT off.
[256]DRAM ODT value: 0x42.
[259]ddr_efuse_type: 0xa
[262]DRAM SIZE =128 M
[264]dram_tpr4:0x0
[266]PLL_DDR_CTRL_REG:0xf8004100
[269]DRAM_CLK_REG:0xc0000000
[272][TIMING DEBUG] MR2= 0x18
[279]DRAM simple test OK.
[281]rtc standby flag is 0x0, super standby flag is 0x0
[286]dram size =128
[289]card no is 0
[291]sdcard 0 line count 4
[293][mmc]: mmc driver ver 2021-05-21 14:47
[303][mmc]: Wrong media type 0x0
[306][mmc]: ***Try SD card 0***
[316][mmc]: HSSDR52/SDR25 4 bit
[319][mmc]: 50000000 Hz
[321][mmc]: 3840 MB
[323][mmc]: ***SD/MMC 0 init OK!!!***
[422]Loading boot-pkg Succeed(index=0).
[426]Entry_name = u-boot
[433]Entry_name = optee
[437]Entry_name = dtb
[440]mmc not para
[442]Jump to second Boot.
M/TC: OP-TEE version: 6aef7bb2-dirty (gcc version 5.3.1 20160412 (Linaro GCC 5.3-2016.05)) #1 Fri Jul 23 09:25:11 UTC 2021 arm
U-Boot 2018.05-g6c4e831 (Sep 28 2025 - 10:28:48 +0000) Allwinner Technology
[00.498]CPU: Allwinner Family
[00.501]Model: sun8iw20
[00.503]DRAM: 128 MiB
[00.506]Relocation Offset is: 04e9b000
[00.535]secure enable bit: 0
[00.538]CPU=1008 MHz,PLL6=600 Mhz,AHB=200 Mhz, APB1=100Mhz MBus=300Mhz
[00.544]gic: sec monitor mode
[00.551]flash init start
[00.553]workmode = 0,storage type = 1
[00.556][mmc]: mmc driver ver uboot2018:2021-06-15 14:00:00
[00.562][mmc]: get sdc_type fail and use default host:tm1.
[00.568][mmc]: can't find node "mmc0",will add new node
[00.572][mmc]: fdt err returned <no error>
[00.576][mmc]: Using default timing para
[00.580][mmc]: SUNXI SDMMC Controller Version:0x50310
[00.598][mmc]: card_caps:0x3000000a
[00.601][mmc]: host_caps:0x3000003f
[00.606]sunxi flash init ok
[00.608]line:703 init_clocks
[00.611]drv_disp_init
request pwm success, pwm7:pwm7:0x2000c00.
[00.624]drv_disp_init finish
[00.627]boot_gui_init:start
[00.629]set disp.dev2_output_type fail. using defval=0
FDT ERROR:fdt_get_all_pin:get property handle pinctrl-0 error:FDT_ERR_INTERNAL
disp_sys_pin_set_state, fdt_set_all_pin, ret=-1
[00.646]
[00.648]info: LCD model is MK20
[00.711]info: LCD_power_on_MK20_PLUS run
[00.714]
[00.716]boot_gui_init:finish
part[00.746]
[00.748]info: LCD model is MK20
[00.751]info: LCD_panel_init_MK20_PLUS run
[00.755]info : init hardwave spi ...
[00.760]info : init hardwave spi finish
partno erro : can't find partition bootloader
522061878098556 bytes read in 0 ms (12.9 MiB/s)
[00.817]info: load image...
[01.467]
no erro : can't find partition bootloader
54 bytes read in 3 ms (17.6 KiB/s)
[01.487]bmp_name=bootlogo.bmp size 76938
76938 bytes read in 9 ms (8.2 MiB/s)
[01.536]Loading Environment from SUNXI_FLASH... OK
[01.572]Item0 (Map) magic is bad
[01.575]the secure storage item0 copy0 magic is bad
[01.581]Item0 (Map) magic is bad
[01.584]the secure storage item0 copy1 magic is bad
[01.589]Item0 (Map) magic is bad
secure storage read widevine fail
[01.595]secure storage read widevine fail with:-1
secure storage read ec_key fail
[01.602]secure storage read ec_key fail with:-1
secure storage read ec_cert1 fail
[01.609]secure storage read ec_cert1 fail with:-1
secure storage read ec_cert2 fail
[01.617]secure storage rea[01.620]LCD open finish
d ec_cert2 fail with:-1
secure storage read ec_cert3 fail
[01.627]secure storage read ec_cert3 fail with:-1
secure storage read rsa_key fail
[01.635]secure storage read rsa_key fail with:-1
secure storage read rsa_cert1 fail
[01.642]secure storage read rsa_cert1 fail with:-1
secure storage read rsa_cert2 fail
[01.650]secure storage read rsa_cert2 fail with:-1
secure storage read rsa_cert3 fail
[01.657]secure storage read rsa_cert3 fail with:-1
[01.662]out of usb burn from boot: not need burn key
partno erro : can't find partition private
root_partition is rootfs
set root to /dev/mmcblk0p5
[01.682]update part info
[01.689]update bootcmd
[01.696]change working_fdt 0x46a5ae70 to 0x46a3ae70
[01.717]update dts
geth_sys_init:624: get node 'gmac0' error
geth_sys_init fail!
[01.724]Board Net Initialization Failed
[01.728]No ethernet found.
Hit any key to stop autoboot: 0
[01.972]no vendor_boot partition is found
Android's image name: t113-pro
[01.985]Starting kernel ...
[01.987][mmc]: MMC Device 2 not found
[01.991][mmc]: mmc 2 not find, so not exit
Langage du code : JavaScript (javascript)
Les trois PADs du dessus sont certainement une UART pour le GD32.













