手機 - Motorola XT897 - 焊接UART



參考資料:
https://wiki.postmarketos.org/index.php?title=Serial_debugging:Cable_schematics&mobileaction=toggle_view_mobile

雖然司徒一直在找尋XT897的UART位置,但是,始終無法如願,如今PostMarketOS終於找到XT897的UART位置,這真是太令人振奮的消息,因為有了UART協助,在移植方面會方便許多,也讓這台機器更具可玩性,不過,司徒依照PostMarketOS的位置焊接UART,發現UART RXD位置標錯,司徒整理如下

第2腳位:RXD
第3腳位:TXD


為了不要破壞漂亮的外殼,因此,司徒仿照PostMarketOS的作法,使用3.5mm耳機孔當作UART輸出腳位,原本PCB焊點需要使用膠帶隔離


3.5mm耳機孔腳位如下:


跳線


RXD接到MIC,TXD接到Left Audio


製作一條UART轉接線


雖然XT897 UART是1.8v,不過,司徒連接到USB轉UART(3.3v)是可以動作且沒有燒掉


/dev/ttyHSL0
Baudrate 115200bps

** Welcome to MBM Next Generation **
[    1638] Power on status from SBL: 0x00000001
[    1642] Powerup reason for kernel: 0x00000080
[    1714] Skip cid validation for gpt_main!
[    1871] validate_partition: successful validation for gpt_main 
[    1876] found valid signed GPT
[    1885] cid_get_cid_data - START
[    1887] page_size = 1000
[    1891] cid_get_cid_data: Version 1 datablock
[    2159] dbval_read_and_validate_cid_datablock - Success
[    2163] dbval_read_and_validate_cid_datablock - END
[    2168] before swap: dbvc_cid =0x0900
[    2172] after swap: dbvc_cid =0x0009
[    2175] set_cid_value: dbvc_cid_status =0x F
[    2245] UTAG [CAFE000C]: not found or empty
[    2248] UTAG [CAFE0009]: not found or empty
[    2252] USB serial no: T069502NTW
[    2255] UTAG [CAFE000D]: not found or empty
[    2259] Hardware Revision: 0x82B0
[    2263] initialize display...
[    2266] Only one panel driver installed, using it by default
[    2475] MOT panel on and power_mode =0x9c
[    2486] not found sp block for MOT_BOTA: type=0x424f5441
[    2491] there is no bota update information
[    2495] starting app lcd_display
[    2498] starting app mbm
[    2501] shared memory reboot flag 0x05170484
[    2505] powering up normally
[    2507] show logo in thread
[    2728] Showing logo completed
[    2730] CID provisioned 
[    2732] Device is consumer 
[    2747] mot_sst_validate_token: Token header incorrect
[    4084] Set MOT SST values
[    4098] Booting Linux
[    4147] token "console" is found. Replace it with "null".
[    4152] CID provisioned 
[    4154] Device is consumer 
[    4157] UTAG [CAFE0014]: not found or empty
[    4173] UTAG [CAFE0006]: not found or empty
[    4176] UTAG [CAFE0007]: not found or empty
[    4180] cmdline: console=null androidboot.hardware=qcom user_debug=31 loglevel=1 zcache=lz4 androidboot.selinux=permissive selinux=0 androidboot.emmc=true androidboot.serialno=T069502NTWt