CHIP – The World’s First Nine Dollar Computer – Hans de Goede, Red Hat

Hans works for Redhat, which has nothing to do with C.H.I.P., Hans is not affiliated with Next Thing Co in any way except as a user of the C.H.I.P.

C.H.I.P. is a full computer it 60x41mm. Core = Allwinnar R8 (1GHz Cortex A8, no virtualisation extensions, Mali 400) + 512MB DDR3 + 4GB NAND + RTL8723BS (802.11b/g/n 2.4GHz + BT 4.0). USB-A, .5mm headphone with mic in or composite video out, USB-B OTG, LiOn/LiPo battery connector (charger is in PMIC).
2 big headers: voltage, LCD/LVDS, CSI, 2x I2C, resistive touch, PWM out, UART. LCD pins can be configured for MMIO (external phy needed). CSI can be configured as SPI2 + MMC2. Roughly 60 pins can be configured as GPIO. One pin is “firmware recovery mode” which is needed to flash an image over USB.
It doesn’t have a good video output on the base board. So need daughterboards with HDMI or VGA out. Pocket chip has LCD + resistive touch + keyboard + case that holds the C.H.I.P. Hans would like to see a daugherboard with wired ethernet. To identify daughterboards the plan is to use 1-wire chips (which have a unique ID so no conflicts, but U-Boot doesn’t have a 1-wire stack).
The board consumes about 2A, so running on USB is difficult.
Mainline support: U-Boot is there, except for the NAND flash (only a simple RO driver is available out of tree) – Free Electrons is working on a mainlining a full NAND driver (cfr. U-Boot). Linux mainline is missing NAND, Wifi/BT (Realtek has an out-of-three driver under GPL, but it’s extremely ugly; someone is working on cleaning it up), video. The IP block for video encoding/decoding has been reverse-engineered, but nobody is working on a driver. Next Thing Co plans to have an out-of-tree driver that uses Allwinner’s Android binary blobs. Similar for GPU. Video output: U-Boot has video output suport, kernel can take this over through simplefb. Maxime Ripard is working on a KMS driver.
A lot of upstream work is done by the linux-sunxi community.
It runs a default Fedora 22 – that kernel and U-Boot already has Allwinner support.


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