This document discusses functional programming on microcontroller units (MCUs) and summarizes the speaker's workshop on this topic. It explores reasons for using functional languages on MCUs and Internet of Things devices due to benefits like strong typing and runtime error avoidance. Several cross-compilers from functional languages to C suitable for MCUs are presented, like Ajhc for Haskell and Rust, along with experiences running them on boards like the mbed LPC1768 and Seeeduino Arch Pro. Debugging options using pyOCD and OpenOCD are also covered.

1. Functional MCU programming
Metasepi Project / Kiwamu Okabe

2. Who am I ?
☆ http://www.masterq.net/
☆ Twitter: @master_q
☆ Organizer of Metasepi Project
☆ A developer of Ajhc Haskell compiler
☆ A Debian Maintainer
☆ 10 years' experience in developing
OS using NetBSD

3. Kick off workshop at Nagoya !
Functional MCU programing workshop
☆ At Nagoya
☆ Meeting minutes
http://metasepi.org/posts/2014-01-05-mbed_fp_0.html
☆ Now planning the next workshop...

4. Why functional lang for MCU?
☆ Internet of Things (IoT)
☆ We will live in IoT world
☆ Can't debug IoT device on the field
☆ Should avoid runtime error
☆ We need strong type !

5. What is functional app?

6. Choice of cross compiler

7. Cross compiler: (A)jhc
http://ajhc.metasepi.org/
☆ Language: Haskell
☆ Haskell language is major !
☆ Need GC heap = Need more memory
☆ Experience running on MCU
ARM Cortex-M
https://github.com/ajhc/demo-cortex-m3

8. Cross compiler: ATS
http://www.ats-lang.org/
☆ Language: ML
☆ Optional GC = Need low memory
☆ No experience running on MCU
☆ Document translated into Japanese
http://jats-ug.metasepi.org/

9. Cross compiler: Rust
http://www.rust-lang.org/
☆ Language: Own syntax like C or JS
☆ Optional GC = Need low memory
☆ Experience running on MCU
ARM Cortex-M
https://github.com/neykov/armboot
☆ Developing by Mozilla
☆ @pirapira knows the detail of it

10. Choice of MCU board

11. Which MCU? Of course mbed!?
Why?
☆ Major
☆ 32bit
☆ Large memory size (> 20kB)
☆ Debugger
☆ Ethernet

12. Which board is good for us...
☆ mbed LPC1768 (¥5,200)
RAM 32kB+32kB
Ethernet
https://mbed.org/platforms/mbed-LPC1768/
☆ Seeeduino Arch Pro ($43.41)
RAM 32kB+32kB
Ethernet
http://www.seeedstudio.com/depot/arch-pro-p-1677.html
☆ FRDM-KL46Z (¥1,634)
RAM 32kB
No Ethernet
http://www.freescale.com/webapp/sps/site/prod_summary.jsp?
code=FRDM-KL46Z

13. Choice of debugger

14. gdbserver: pyOCD
https://github.com/mbedmicro/pyOCD
☆ Only for MCU using CMSIS-DAP
☆ But now support only mbed LPC1768
☆ In future, support more board ?

15. gdbserver: OpenOCD
http://openocd.sourceforge.net/
☆ Comming CMSIS-DAP support!
☆ Need HIDAPI library
http://www.signal11.us/oss/hidapi/

16. OpenOCD enabling CMSIS-DAP
$
$
$
$
$
$
git clone git://github.com/signal11/hidapi.git
cd hidapi
./bootstrap
./configure
make
sudo make install
$ git clone https://github.com/master-q/openocd.git
$ cd openocd
$ git checkout masterq-mbedfest-201401
$ ./bootstrap
$ ./configure --enable-cmsis-dap
--ship-Olimex ARM-JTAG-EW Programmer
yes (auto)
CMSIS-DAP Compliant Debugger
yes
$ make
Some time the following FRDM-KL46Z patch is useful.
http://permalink.gmane.org/gmane.comp.debugging.openocd.devel/24258

17. On mbed LPC1768
$ sudo ./src/openocd -f tcl/board/mbed-lpc1768.cfg
$ arm-none-eabi-gdb
(gdb) target remote
(gdb) monitor reset
(gdb) load
Blink.elf
localhost:3333
halt
Push hard rest button.
(gdb) c
But too slow...
Transfer rate: 50 bytes/sec, 3818 bytes/write.
:(

18. On Seeeduino Arch Pro
Same as mbed LPC1768.

19. On FRDM-KL46Z
Use project at https://github.com/0xc0170/kinetis_klxx_gcc.
$ sudo ./src/openocd -f tcl/board/frdm-kl46z.cfg
--snip-cortex_m reset_config sysresetreq
Info : CMSIS-DAP: FW Version = 1.0
Info : SWCLK/TCK = 0 SWDIO/TMS = 1 TDI = 0 TDO = 0 nTRST = 0
nRESET = 1
Info : DAP_SWJ Sequence (reset: 50+ '1' followed by 0)
Info : CMSIS-DAP: Interface ready
Info : clock speed 100 kHz
Info : IDCODE 0x0bc11477
Info : MKL46Z256VLL4.cpu: hardware has 2 breakpoints, 2 watchpoints
Info : accepting 'gdb' connection from 3333
Warn : Cannot communicate... target not halted.
Error: auto_probe failed
Error: Connect failed. Consider setting up a gdb-attach event for
the target to prepare.
Error: attempted 'gdb' connection rejected
X(

20. Be a hacker such as ねむいさん
http://nemuisan.blog.bai.ne.jp/
☆ OpenOCD hacker
☆ There is his patch at following URL
http://nemuisan.blog.bai.ne.jp/?eid=192848#OPENOCD

21. Functional programming fanzine
☆ http://www.paraiso-lang.org/ikmsm/
☆ About Haskell or OCaml or . . .
☆ About Ajhc in C84 book
☆ About Android app with Haskell in
C85 book
☆ Call me if you read it!
http://www.paraiso-lang.org/ikmsm/books/c85.html