ok, been quite busy, 3 to 4 different things going on.
first one: i've been working on getting the eoma68-a20 board up and running (booting) out of NAND flash, that's been quite hair-raising. using a sunxi 3.15-10-rc5 kernel i was able to use the standard mtd-tools package to erase and write to the hynix TSOP48 NAND chip, placing an SPL-enabled recent version of u-boot onto it. this all worked fine... except it turns out that MLC NAND can self-destruct just by reading! all i can say is, no wonder allwinner's bootloader process is so damn complex! it's like a 4-stage boot: boot0 (minimum bring-up), boot1 (capable of reading NAND as well as SD/MMC FAT partitions), then u-boot (modified to read allwinner's strange partition format) and finally linux kernel.
second, the jz4775 CPU Card is finally underway: http://rhombus-tech.net/ingenic/jz4775/news/
this is the first FSF-Endorseable CPU Card, using the 1.2ghz low-power Ingenic MIPS. it seems strange to put a $3 processor alongside $2.50 of NAND Flash and then put in almost $12 of DDR3 RAM ICs (2 GB RAM) but the threshold where SoCs were no longer the most expensive part of a BOM was passed a loong time ago.
third, the laptop main board, i've got everything working except the LCD. i've blown up 2 LCDs already, it was necessary to buy 2 more. first mistake was that it was hard to read the datasheet so the connector was reversed: that resulted in -20V being shoved up the backside of the +3.3v sensitive ICs on the LCD, end result when i was finally able to make up a reversed-cable, the "magic smoke" left that LCD. also i hadn't noticed that i'd shorted the 5V rail to the 3.3v rail, which didn't help, and may have damaged some of the GPIOs on one of the EOMA68-A20 boards i have here. still quite a bit to investigate there.
fourth, i've managed to smoke about 3-4 Power ICs already - various MOSFETs, two 3 Amp RT8288 PMICs from microdesktop boards i'm using for test purposes - all to get the laptop power / charger board up and running. annoying! but finally a couple of hours ago, by making up a 2nd board with minimal components, i managed to get the LTC4155 up and recognised on the I2C bus, as well as check that it was outputting stable 5V from USB-style input. the next phase is to populate the over-voltage and reverse-voltage protection components.
it's getting there... it's just slower than i would like.
l.