Inet U70B

= Identification =

This white-label board may appear in tablets by other brands. One tablet using this board is the "Nimbus 17 V1". On the back of the tablet, the following is printed: cm2 NIMBUS performance 2AM4S-NIMBUS17V1 [serial number sticker]

The PCB has the following silkscreened on it: INET-U70B-REV01 Zeng-gc 2016-11-30

In android, under Settings->About Tablet, you will find:
 * Model Number: Nimbus 17 V1
 * Build Number: Nimbus_20171110_V001

More android build info: [ro.build.characteristics]: [tablet] [ro.build.date.utc]: [1510293882] [ro.build.date]: [Fri Nov 10 14:04:42 CST 2017] [ro.build.description]: [astar_ibt_8723bs-eng 4.4.2 KVT49L 20171110 test-keys] [ro.build.display.id]: [Nimbus_20171110_V001] [ro.build.fingerprint]: [iNet/astar_ibt_8723bs/astar-ibt-8723bs:4.4.2/KVT49L/20171110:eng/test-keys] [ro.build.host]: [inet-server01] [ro.build.id]: [KVT49L] [ro.build.product]: [astar-ibt-8723bs] [ro.build.tags]: [test-keys] [ro.build.type]: [eng] [ro.build.user]: [inet-soft03] [ro.build.version.codename]: [REL] [ro.build.version.incremental]: [20171110] [ro.build.version.release]: [4.4.2] [ro.build.version.sdk]: [19] [ro.product.board]: [exdroid] [ro.product.brand]: [Nimbus] [ro.product.device]: [astar-ibt-8723bs] [ro.product.firmware]: [2.1_20160317] [ro.product.manufacturer]: [unknown] [ro.product.model]: [Nimbus 17 V1] [ro.product.model_mtp]: [Nimbus_17_V1] [ro.product.name]: [astar_ibt_8723bs] [ro.reversion.aw_sdk_tag]: [exdroid4.4.2_r2-a33-v2.1] [ro.rock.gota.brand]: [unknown] [ro.rock.gota.model]: [Nimbus 17 V1] [ro.rock.gota.model_mtp]: [Nimbus_17_V1] [ro.rock.gota.version]: [Nimbus_20171110_V001_1510293882]

= Sunxi support =

Manual build
You can build things for yourself by following our Manual build howto and by choosing from the configurations available below.

Mainline U-Boot
Use the  build target.

Mainline kernel
Use the  device-tree binary.

= Tips, Tricks, Caveats =

= Adding a serial port (voids warranty) =



See the UART howto. A microSD breakout board is recommended for UART access. This does not require disassembly.

Device disassembly
Pop off the back cover by releasing the clips around the edges. The speaker is loosely glued to the back cover, so you will need to gently remove it before fully removing the back cover.

Locating the UART
There are UART TX and RX pads near the SD card slot. You can solder wires onto these pads, but since they are the same pins (PF2 and PF4) used for the microSD card, there is no advantage over using a microSD breakout board to access them.

= Pictures =

= Schematic =

No schematic is available, but here is some hardware info gathered from the stock android build:

GPIO mapping: GPIOs 0-383, platform/sunxi-pinctrl, sunxi-pinctrl: gpio-36 (cd                  ) in  lo gpio-225 (?                   ) out lo gpio-232 (otg_id              ) in  hi gpio-233 (?                   ) out lo

I2C mapping: root@astar-ibt-8723bs:/ # grep. /sys/bus/i2c/devices/*-0*/name /sys/bus/i2c/devices/0-0040/name:gslX680 /sys/bus/i2c/devices/1-0018/name:bma250

Pinctrl mapping: root@astar-ibt-8723bs:/ # cat /sys/kernel/debug/pinctrl/pinctrl-handles Requested pin control handlers their pinmux maps: device: sunxi-pinctrl current state: none device: axp-pinctrl current state: none device: twi0 current state: default state: default type: MUX_GROUP controller sunxi-pinctrl group: PH2 (103) function: twi0 (26) type: MUX_GROUP controller sunxi-pinctrl group: PH3 (104) function: twi0 (26) device: twi1 current state: default state: default type: MUX_GROUP controller sunxi-pinctrl group: PH4 (105) function: twi1 (27) type: MUX_GROUP controller sunxi-pinctrl group: PH5 (106) function: twi1 (27) device: twi2 current state: default state: default type: MUX_GROUP controller sunxi-pinctrl group: PE12 (75) function: twi2 (20) type: MUX_GROUP controller sunxi-pinctrl group: PE13 (76) function: twi2 (20) device: uart0 current state: default state: default type: MUX_GROUP controller sunxi-pinctrl group: PF2 (83) function: uart0 (8) type: CONFIGS_GROUP controller sunxi-pinctrl group PF2 (83) 00010002 type: MUX_GROUP controller sunxi-pinctrl group: PF4 (85) function: uart0 (8) type: CONFIGS_GROUP controller sunxi-pinctrl group PF4 (85) 00010002 device: uart1 current state: default state: default type: MUX_GROUP controller sunxi-pinctrl group: PG6 (93) function: uart1 (17) type: CONFIGS_GROUP controller sunxi-pinctrl group PG6 (93) 00010002 type: MUX_GROUP controller sunxi-pinctrl group: PG7 (94) function: uart1 (17) type: CONFIGS_GROUP controller sunxi-pinctrl group PG7 (94) 00010002 type: MUX_GROUP controller sunxi-pinctrl group: PG8 (95) function: uart1 (17) type: CONFIGS_GROUP controller sunxi-pinctrl group PG8 (95) 00010002 type: MUX_GROUP controller sunxi-pinctrl group: PG9 (96) function: uart1 (17) type: CONFIGS_GROUP controller sunxi-pinctrl group PG9 (96) 00010002

PWM mapping: root@astar-ibt-8723bs:/ # cat /sys/kernel/debug/pwm platform/sunxi_pwm, 2 PWM devices pwm-0  (lcd                 ): requested pwm-1  ((null)              ):

U-Boot log: U-Boot 2011.09-rc1-00024-g36bb972 (Jun 26 2017 - 09:39:25) Allwinner Technology

[     0.271]version: 2.1.0 [     0.360]pmbus:   ready [     0.362]PMU: AXP221 [     0.364]PMU: AXP22x found [     0.368]PMU: dcdc3 1200 [     0.371]PMU: pll1 1008 Mhz,PLL6=600 Mhz AXI=336 Mhz,AHB=200 Mhz, APB1=100 Mhz set power on vol to default dcdc1_vol = 3000 dcdc2_vol = 1100 dcdc3_vol = 1200 dcdc4_vol = 0 dcdc5_vol = 1500 aldo2_vol = 2500 aldo3_vol = 3000 find power_sply to end vbus pc exist, limit to pc fel key old mode run key detect no key found no key input dram_para_set start dram_para_set end [     0.496]DRAM:  512 MiB relocation Offset is: 15aee000 smcl's set manager is NULL OSAL_Power_Enable: workmode = 0 [     0.702]NAND: NAND_UbootInit NAND_UbootInit start NB1 : enter NAND_LogicInit uboot:nand version: 2 32 20170220 1103 nand : get id_number_ctl from script, 2 uboot:nand info: ab14dead ffff4a42 318c 60704 6 nand : get sorting_flag fail, a nand : get CapacityLevel fail, 5fb7fc70 not burn nand partition table! NB1 : nftl num: 2 init nftl: 0 NB1 : NAND_LogicInit ok, result = 0x0 [     1.237]sunxi flash init ok sunxi secure storage is not supported find key burned flag In:   serial Out:  serial Err:  serial fastboot partitions -total partitions:12- -name-       -start-       -size- bootloader : 1000000       2000000 env        : 3000000       1000000 boot       : 4000000       1000000 system     : 5000000       30000000 misc       : 35000000      1000000 recovery   : 36000000      2000000 cache      : 38000000      20000000 metadata   : 58000000      1000000 private    : 59000000      1000000 klog       : 5a000000      1000000 alog       : 5b000000      4000000 UDISK      : 5f000000      0 --- base bootcmd=run setargs_nand boot_normal bootcmd set setargs_nand key 0 recovery key high 100, low 2 cant find fstbt value misc partition found misc_message->command = 0 to be run cmd=run setargs_nand boot_normal mount part name bootloader cant open script.bin, maybe it is not exist WORK_MODE_BOOT board_status_probe [     1.351]pre sys mode sunxi_bmp_logo_display screen_id =0, screen_width =1024, screen_height =600 [     1.474]Hit any key to stop autoboot:  0 read boot or recovery all [     1.953]sunxi flash read :offset 4000000, 12626790 bytes OK no signature [     1.962]ready to boot para err in disp_ioctl, cmd = 0xa,screen id = 1 [     1.969][mmc]: MMC Device 2 not found [     1.973][mmc]:  mmc  not find,so not exit NAND_UbootExit NB1 : NAND_LogicExit nand release dma:0 [     1.977] Starting kernel ...

PMIC info from dmesg: [   0.520045] axp22_board axp22_board: AXP (CHIP ID: 0x06) detected [   0.522136] axp22_dcdc1: 1600 <--> 3400 mV at 3000 mV [    0.522136] axp22_dcdc2: 600 <--> 1540 mV at 1100 mV [    0.522136] axp22_dcdc3: 600 <--> 1860 mV at 1200 mV [    0.522136] axp22_dcdc4: 600 <--> 1540 mV at 1100 mV [    0.522136] axp22_dcdc5: 1000 <--> 2550 mV at 1500 mV [    0.522136] axp22_rtc: 3000 mV [    0.522136] axp22_aldo1: 700 <--> 3300 mV at 3000 mV [    0.522136] axp22_aldo2: 700 <--> 3300 mV at 2500 mV [    0.522136] axp22_aldo3: 700 <--> 3300 mV at 3000 mV [    0.522136] axp22_dldo1: 700 <--> 3300 mV at 700 mV [    0.522136] axp22_dldo2: 700 <--> 3300 mV at 700 mV [    0.522136] axp22_dldo3: 700 <--> 3300 mV at 700 mV [    0.522136] axp22_dldo4: 700 <--> 3300 mV at 700 mV [    0.522136] axp22_eldo1: 700 <--> 3300 mV at 700 mV [    0.522136] axp22_eldo1: supplied by axp22_dcdc1 [   0.522136] axp22_eldo2: 700 <--> 3300 mV at 700 mV [    0.522136] axp22_eldo2: supplied by axp22_dcdc1 [   0.522136] axp22_eldo3: 700 <--> 3300 mV at 700 mV [    0.522136] axp22_eldo3: supplied by axp22_dcdc1 [   0.522136] axp22_dc5ldo: 700 <--> 1400 mV at 1100 mV [    0.522136] axp22_ldoio0: 700 <--> 3300 mV at 3800 mV [    0.522136] axp22_ldoio1: 700 <--> 3300 mV at 3800 mV [    0.530071] axp22_dc1sw: at 700 mV [    0.530071] axp22_dc1sw: supplied by axp22_dcdc1 [   0.565902] no usbc(0) det_vbus gpio and try to axp det_pin [   0.669659] [rtl8723bs]: module power name axp22_dldo1 [   0.669673] [rtl8723bs]: module power ext1 name axp22_dldo2 [   0.669849] [rtl8723bs]: rtl8723bs module power set by axp. [  12.940521] lcd_power0:axp22_dc1sw [  14.590835] [sw_device]:get_power_para: power_ldo = axp22_ldoio1,power_ldo_vol = 3300,power_io = 0,reset_pin = 225

More info from dmesg: [  24.900024] ctp_wakeup gpio number is 225 [  24.904473] ctp_irq gpio number is 37

= Also known as =


 * Nimbus 17 V1

= See also =


 * https://fccid.io/2AM4S-NIMBUS17V1 (FCC registration)