Closest to center pin is TX, 3.3v
Hold enter to enter uboot during boot:
Anjoy # printenv
Mstarbin=20150709
bootargs=ubi.mtd=UBI,2048 root=/dev/mtdblock8 rootfstype=squashfs ro init=/linuxrc LX_MEM=0xffe0000 mma_heap=mma_heap_name0,miu=0,sz=0x9E9C000 mma_heap=mma_heap_ipu,miu=0,sz=0x164000 cma=2M mtdparts=nand0:768k@1280k(IPL0),384k(IPL_CUST0),384k(IPL_CUST1),384k(UBOOT0),384k(UBOOT1),256k(ENV0),0x500000(KERNEL),0x500000(RECOVERY),0x2000000(rootfs),0x200000(MISC),0x500000(DATA),-(UBI)
bootcmd=nand read.e 0x22000000 KERNEL 0x500000; bootm 0x22000000;nand read.e 0x22000000 RECOVERY 0x500000; bootm 0x22000000
ethact=sstar_emac
ethaddr=00:30:1b:ba:02:db