Chopstx 1.18

[NIIBE Yutaka]

Hello,

Chopstx 1.18 is released.

	tag release/1.18
	Tagger: NIIBE Yutaka <gniibe at fsij.org>
	Date:   Mon Dec 30 10:51:15 2019 +0900
	commit cc49f4ef23f119c7279bd980eb54a76100ef7446

It has fixes for chopstx_poll with condition variables and GNU/Linux emulation.

This release is from STABLE-BRANCH-1 branch.

In the master branch (for 2.0), I pushed changes for RISC-V port (from
riscv branch).  The riscv branch is dead now.  I'm currently using
picolibc for RISC-V port.

In "example-lcd" directory of master, we have an example using USB, LCD
(through SPI) and serial for the target board.  The LCD screen
resolution is 160x80.  It requires 25600-byte of memory to store screen
data from host, while GD32VF103 only has 32KiB.  The USB module on
GD32VF103 is different one.  It supports modes of Hub and On-the-Go,
too.  It appears as same(similar) as STM32F105/107 (not STM32F103).

The target board is Sipeed Longan nano.  It is available at Seeed
Studio.  Distributors include Digikey, Mouser, and Akiduki.

While I implemented a USB driver for GD32VF103 (and possibly for
STM32F105/107), I wondered availability of free hardware design of USB
module.  This month, I found a blog article:

    https://antmicro.com/blog/2019/12/testing-usb-cores-with-python-and-cocotb/

Happy Hacking (and/in) Happy Holidays,
--