[Gnuk-users] Chopstx for Cortex-A7 support

[NIIBE Yutaka]

Hello,

I bought two Orange Pi PC(s) (it took a month to get them).  It has
Allwinner H3 as a main chip, which has four cores.

Based on Kaz Kojima's work for Raspberry Pi 2, I ported Chopstx to the
board.  The branch is here:

    http://git.gniibe.org/gitweb/?p=chopstx/chopstx.git;a=shortlog;h=re
fs/heads/cortex-a7-support-opi2

I think it works now (with four cores), somehow.  I have not yet
managed to configure DRAM, and it runs on SRAM.

I learned that those boards and chips are not good yet as free
computing platform, since some important technical information is not
available to public.  This is major difference from STM32F103 or chip
based on Cortex-M3.

For Allwinner H3, it seems that many have been doing good jobs to
disclose technical information and code, so, it's getting better.

I did some reverse engineering for boot0, and got information/code
from the Allwinner mainlining activities of u-boot and Linux.  Then, I
managed to implement a boot code to enable use of JTAG debugger.

Currently, I load a sample program with Chopstx through JTAG debugger.

When I will be able to enable DRAM, I will be able to do something
interesting.

It seems that DRAM configuration and/or power management is difficult
area for free computing.
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