====== Imagination CI20 reference board ======

NOTE: this is a work in progress!

===== Overview =====

The CI20 reference board from Imagination Technologies contains:

  * Ingenic JZ7480
  * 1GB RAM
  * (TODO)

===== What's working =====

  * SMP
  * USB1
  * Basic NEMC bus, required for ethernet and NAND
  * Ethernet
  * Serial console

There are apparently multiple UARTs on this board -see http://elinux.org/CI20_Hardware#Dedicated_UART_header for the console uart (uart4).

===== Workspace =====

  * https://github.com/akabaev/freebsd ; branch 'kan-ci20'.

===== Building FreeBSD =====

  * make TARGET=mips TARGET_ARCH=mipsel TARGET_CPUTYPE=mips32r2 buildworld
  * make TARGET=mips TARGET_ARCH=mipsel TARGET_CPUTYPE=mips32r2 buildkernel KERNCONF=CI20

Use TARGET_ARCH=mipselhf to enable hard float support. This appears to work (thank you, Ruslan!), but was only lightly tested on this board.

===== Booting FreeBSD =====

  * you need kernel.tramp.bin from the obj directory, NOT the kernel that's installed in DESTDIR/boot/kernel
  * at uboot:
  * setenv ipaddr %%<%%local ip>
  * setenv serverip %%<%%ip address of tftp server>
  * tftpboot 0x88000000 kernel.tramp.bin
  * go 0x88000000 hint.dme.0.macaddr=${ethaddr}

===== Notes =====

The earlier software version (Debian 7) shipped with a uboot/dts that used uart0. This isn't the dedicated uart4 connector.

When you upgrade to debian 8 it'll come with an updated uboot/dts which will change the dts to point the console out uart4.

%%FreeBSD%%'s dts (sys/gnu/dts/mips/ingenic/ci20.dts) sets stdout-path = &uart4, which matches the updated firmware. For the Debian 7 firmware, you should change this to uart0 before compiling the kernel so the bootloader console and %%FreeBSD%% serial console match.

===== Links =====

  * http://elinux.org/MIPS_Creator_CI20
  * http://elinux.org/CI20_Hardware
  * http://elinux.org/CI20_Distros