YBKJ A20

= Identification = PCB Board marked with "YBKJ_A20_V3.0". There are no other identifiable markings.

In android, under Settings->About Tablet, you will find:
 * Model Number:  SoftwinerEvb
 * Build Number:  sugar_ref001-eng 4.2.2 JDQ39 20131115 test-keys
 * Android Kernel: 3.3.0 zhoujiequan@zhoujiequan-desktop #25

= Sunxi support =

Current status

 * U-boot patch still missing.
 * Sunxi kernel 3.4 + Debian armhf confirmed working
 * No DTB for mainline yet.

Manual build

 * For building u-boot, use the "" target.
 * The .fex file can be found in sunxi-boards as ybkj_a20.fex

Everything else is the same as the manual build howto.

= Tips, Tricks, Caveats =

FEL mode
There is no USB OTG so FEL mode is pointless. However, it can be triggered by sending '2' via the serial console as normal.

Meminfo dump
dram_clk         = 432 dram_type        = 3 dram_rank_num    = 1 dram_chip_density = 2048 dram_io_width    = 16 dram_bus_width   = 32 dram_cas         = 9 dram_zq          = 0x7f dram_odt_en      = 0 dram_tpr0        = 0x38d48893 dram_tpr1        = 0xa0a0 dram_tpr2        = 0x22a00 dram_tpr3        = 0x0 dram_emr1        = 0x4 dram_emr2        = 0x10 dram_emr3        = 0x0

= Adding a serial port (voids warranty) =



Device disassembly
Lid is held on with a few plastic clips. I was able to remove it without any tools as it was quite loose.

Locating the UART
Connector J10 is conveniently silk screened with pinout for serial port. Just solder on jumper leads according to our UART howto.

= Pictures =

= Also known as =

Sold under many descriptions on Ebay.

= See also =