mruby machine - An Operating System for Microcontroller

HASUMI Hitoshi

2020-09-04

Me
HASUMI Hitoshi（羽角均）
@hasumikin（ハスミキン）
From Ruby City Matsue,
a holy place of
（熱燗）
Developer on Rails
（レールに乗った開発者）
Coffee
Curry
Soba (NoEmojiError)

Motivation
MicroPython
Generally, we keep minimal configuration of
MicroPython under 80K of ARM Thumb2 code
(which includes compiler and interactive
prompt, ...). That means a Cortex-M
microcontroller with 128KB of flash can host a
minimal version together with some hardware
drivers.
[cited from `https://github.com/micropython/micropython/wiki/FAQ']

Motivation
MicroPython
Regarding RAM usage, (...) 8KB is minimal
amount to run simple scripts. As Python is
interpreted high-level language, the more
memory you have, the more capable
applications you can run. The reference
MicroPython board, PyBoard, has 128KB of RAM.
[cited from `https://github.com/micropython/micropython/wiki/FAQ']

Motivation
mruby and mruby/c
Flashing mruby application into 128KB ROM and
running it on 128KB RAM are difficult
mruby/c runs on 64KB RAM but it doesn't have
mruby compiler
You have to compile Ruby script into VM code before
embedding

Motivation
MicroPython:
"Overwhelming, we are!"
「圧倒的じゃないか、我が軍は」

Motivation
Would it be great if we have a
smaller mruby compiler?

Target Microcontroller
PSoC5LP: Reference board of mruby/c
Arm Cortex-M3 32bit processor
64KB RAM
256KB ROM
It will be comparable to MicroPython if Ruby runs
on PSoC5LP with compiler

Terms
mruby
A Ruby implementation for general embedded purpose
mrbc
The original mruby compiler bundled with mruby
mruby/c
Another implementation of mruby VM for one-chip
microcontroller
It doesn't have compiler

Terms
mmrbc (mini mruby compiler)
Another mruby compiler for one-chip microcontroller
mmruby (mini mruby) = mmrbc + mruby/c
mruby machine
A microcontroller embedded with integration of
mmruby, CUI shell and peripheral drivers

Cross compilation tools for bare metal Arm
arm-none-eabi-gcc, arm-none-eabi-ar, arm-none-
eabi-ld, arm-none-eabi-strip, etc.
What is "arm-none-eabi-" ?
arm: Arm architecture
none: Without OS (Bare metal)
eabi: Embedded Application Binary Interface

Three tool-chains in my laptop (Intel 64)
1. (x86_64-linux-gnu-)gcc
Usual compilation in daily development
2. arm-linux-gnueabi-gcc
Binary runs on QEMU (machine emulator)
3. arm-none-eabi-gcc (--with-newlib)
To make a final library archive (libmmrbc.a) for
bare metal Arm

Docker image
((‘tag:center’))
https://hub.docker.com/r/
hasumikin/arm-none-eabi-tools

C Library
glibc (GNU C Library)
Newlib
Another C library especially for embedded system
Some implementation is missed. eg) regex.c
Newlib-nano
Even smaller version of Newlib for Arm processor
Yet other libraries
EGLIBC, Clibc, sglibc, etc.

Repo
https://github.com/hasumikin/mmruby

Features of mmrbc
Portable and Less dependent
Doesn't depend on mruby nor mruby/c
(To the contrary, mrbc depends on mruby itself)
Depends on only standard C library including Newlib(-
nano)
Can be integrated with both mruby and mruby/c

Features of mmrbc
Small (by linking to Newlib-nano)
Fits in less than 256KB ROM (including mruby/c VM
and some application code)
Runs enough on less than 128KB RAM

Features of mmrbc
Lemon as a parser generator instead of Yacc/Bison
Originally a parser generator of SQLite

Yacc/Bison
LALR(1) parser generator, typical choice of parser
generator
Yacc (Barkley Yacc)
Non-reentrant
Parser-Calls-Lexer style (CRuby and mruby use it)
Bison (Gnu Bison. Modernized version of Yacc)
Reentrant, Thread-Safe and Lexer-Calls-Parser style
(You can also select old Yacc style)

Lemon
Reentrant
Lexer-Calls-Parser style

$Parser-Calls-Lexer style (Yacc) yyparse(p); /* in y.tab.c (generated by Yacc) */ int yyparse(parser_state *p) { yytoken = yylex(yylval, p); /* makes AST according as you defined */ ... goto yyhogefuga; ... } /* yylex() is called by parser */ int yylex(void *lval, parser_state *p) { # Find next token and return token type return tokenType; } GenerateVMCode(p->ast);$ Lexer-Calls-Parser style (Lemon)
/* in your own Lexer */
while (hasMoreToken(rubyScript)) {
token = getToken(rubyScript);
Parse(parser, tokenType, token);
}
Parse(parser, 0, "");
/* in parse.c (generated by Lemon) */
void Parse(void *yyp, int yymajor, ...) {
/* makes AST according as you defined */
...
}
GenerateVMCode(p->ast);

Lexer-Calls-Parser style (Lemon)
/* in your own Lexer */
while (hasMoreToken(rubyScript)) {
token = getToken(rubyScript);
Parse(parser, tokenType, token);
}
Parse(parser, 0, "");
/* in parse.c (generated by Lemon) */
void Parse(void *yyp, int yymajor, ...) {
/* makes AST according as you defined */
...
}
GenerateVMCode(p->ast);

Lemon
LALR(1) parser generator as well
Reentrant
Lexer-Calls-Parser style
Generated parser is, I'm still not sure though,
Faster than Yacc/Bison (according to its document)
Smaller code (according to someone)
Grammar syntax of parse.y is different from Yacc/
Bison

Lemon
https://sqlite.org/src/doc/trunk/doc/lemon.html

RAM consumption
mruby's branch
`mruby3` as of August 14th

RAM consumption
To make things simple, both mrbc and mmrbc are
built for x86_64 architecture
using malloc() and free() of glibc
(mmrbc usually uses mrbc_alloc() to manage heap area)
Linux file system to load Ruby script
(microcontroller doesn't have file system)
As a result, we can simply compare with valgrind

$RAM consumption Analysis command looks like: valgrind \ --tool=massif \ --stacks=yes \ path/to/(mrbc|mmrbc) path/to/script.rb Showing the result: ms_print massif.out.xxxx | less$ RAM consumption: Case 1
Ruby code:
# hello_world.rb
puts "Hello World!"
Output:
Hello World!

RAM consumption: Case 1
Ruby code:
# hello_world.rb
puts "Hello World!"
Output:
Hello World!

RAM consumption: Case 1 / mrbc
--------------------------------------------------------------------------------
Command:
../mruby/build/host/bin/mrbc ./hello_world.rb
Massif arguments:
--stacks=yes
ms_print arguments: massif.out.4087
--------------------------------------------------------------------------------
KB
157.8^
#
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: ::: ::: ::: ::: : : ::: : @:: ::@: :: ::@ :::: :: :: @: :: ::@ @#
0 +----------------------------------------------------------------------->Mi
0
3.235

RAM consumption: Case 1 / mmrbc
--------------------------------------------------------------------------------
Command:
../mmruby/build/host-production/bin/mmrbc ./hello_world.rb
Massif arguments:
--stacks=yes
ms_print arguments: massif.out.1652
--------------------------------------------------------------------------------
KB
11.17^
#
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@ :@: : :: @@#:::::
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@: :::@:::@:::@:::@@#::::::
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0 +----------------------------------------------------------------------->ki
0
224.5

$RAM consumption: Case 2 Ruby code: # idiotic_script.rb ary = Array.new(3) ary[0] = {a: 123e2} ary[0][:key] = "string" ary[1] = %w(abc ABC Hello) ary[2] = 0x1f ary[3] = !true puts "my name is #{self.class}, result is #{ary[2] * ary[0][:a]}" p ary$ RAM consumption: Case 2
Output:
my name is Object, result is 381300
[{:a=>12300, :key=>"string"}, ["abc", "ABC", "Hello"], 31, false]

RAM consumption: Case 2
Output:
my name is Object, result is 381300
[{:a=>12300, :key=>"string"}, ["abc", "ABC", "Hello"], 31, false]

RAM consumption: Case 2 / mrbc
--------------------------------------------------------------------------------
Command:
../mruby/build/host/bin/mrbc ./idiotic_script.rb
Massif arguments:
--stacks=yes
ms_print arguments: massif.out.4133
--------------------------------------------------------------------------------
KB
162.9^
##
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:: :::: ::::: :: :: ::: :@ :::: @ :: ::@:: ::: :::@ :: :::@ @:@# :
|
:: :::: ::::: :: :: ::: :@ :::: @ :: ::@:: ::: :::@ :: :::@ @:@# :
0 +----------------------------------------------------------------------->Mi
0
3.470

RAM consumption: Case 2 / mmrbc
--------------------------------------------------------------------------------
Command:
../mmruby/build/host-production/bin/mmrbc idiotic_script.rb
Massif arguments:
--stacks=yes
ms_print arguments: massif.out.13414
--------------------------------------------------------------------------------
KB
53.20^
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0 +----------------------------------------------------------------------->Mi
0
1.616

RAM consumption: Summary
━━━━━━━━━━┳━━━━━┳━━━━━
Ruby script
┃ mrbc ┃ mmrbc
━━━━━━━━━━╋━━━━━╋━━━━━
hello_world.rb
┃ 157.8KB ┃ 11.17KB
━━━━━━━━━━╋━━━━━╋━━━━━
idiotic_script.rb ┃ 162.9KB ┃ 53.20KB
━━━━━━━━━━┻━━━━━┻━━━━━
Note: These results are larger than possible results on
32bit architecture because of pointer size

$Idiotic script # idiotic_script.rb ary = Array.new(3) ary[0] = {a: 123e2} ary[0][:key] = "string" ary[1] = %w(abc ABC Hello) ary[2] = 0x1f ary[3] = !true puts "my name is #{self.class}, result is #{ary[2] * ary[0][:a]}" p ary => my name is Object, result is 381300 [{:a=>12300, :key=>"string"}, ["abc", "ABC", "Hello"], 31, false] Syntax that mmrbc can compile$ $Syntax implemented lvar, $gvar, @ivar, CONSTANT assignment, fcall, method chain Literals: Array, Hash, String, Fixnum, Float, etc. Keywords: true, false, nil, return, self, etc. +, -, *, /, %, **, +=, -=, *=, /=, %=, &=, |=, ^=, **=, <<=, >>= !, ~, +, -, not, &, |, ^, <<, >> Syntax sugar: %w(a b c) Interpolation: "The answer is #{get_result(@attr)}!"$ Syntax
under construction
if then elif else end, unless
case when else then
while, until, break, next, redo, retry, for in
[0,1].each do |var| end
def method_name(arg); end
class MyClass < ParentClass; end
rescue, ensure
..., etc.

Syntax
under construction
if then elif else end, unless
case when else then
while, until, break, next, redo, retry, for in
[0,1].each do |var| end
def method_name(arg); end
class MyClass < ParentClass; end
rescue, ensure
..., etc.

Roadmap
https://github.com/hasumikin/mmruby/issues/6

Code size (to estimate ROM consumption)
% ls -l
(...)
.rwxrwxrwx
.rwxrwxrwx
.rwxrwxrwx
.rwxrwxrwx
609k
903k
650k
425k
hasumi
hasumi
hasumi
hasumi
17
17
17
17
Aug
Aug
Aug
Aug
7:03
7:03
7:03
7:03
mruby_machine_PSoC5LP.a
mruby_machine_PSoC5LP.elf
mruby_machine_PSoC5LP.hex
mruby_machine_PSoC5LP.map
% size mruby_machine_PSoC5LP.elf
text
data
bss
dec
hex filename
136080
320 63009 199409 30af1 mruby_machine_PSoC5LP.elf

Summary
mmrbc is a mini mruby compiler
VM code runs on both mruby VM and mruby/c VM
Still incomplete regarding syntax and memory
efficiency
mruby machine
= mmrbc + mruby/c + shell + dirivers
Runs on PSoC5LP { RAM: 64KB, ROM: 256KB }

Description

Presentation slide for RubyKaigi Takeout 2020

Text

Page: 1

mruby machine
An Operating System for Microcontroller
HASUMI Hitoshi @hasumikin
September 4-5, 2020

Page: 2

Me
HASUMI Hitoshi（羽角 均）
@hasumikin（ハスミキン）
From Ruby City Matsue,
a holy place of
（熱燗）
Developer on Rails
（レールに乗った開発者）
Coffee
Curry
Soba (NoEmojiError)

Page: 3

Page: 4

Chapter 1
Background

Page: 5

Motivation
MicroPython
Generally, we keep minimal configuration of
MicroPython under 80K of ARM Thumb2 code
(which includes compiler and interactive
prompt, ...). That means a Cortex-M
microcontroller with 128KB of flash can host a
minimal version together with some hardware
drivers.
[cited from `https://github.com/micropython/micropython/wiki/FAQ']

Page: 6

Motivation
MicroPython
Regarding RAM usage, (...) 8KB is minimal
amount to run simple scripts. As Python is
interpreted high-level language, the more
memory you have, the more capable
applications you can run. The reference
MicroPython board, PyBoard, has 128KB of RAM.
[cited from `https://github.com/micropython/micropython/wiki/FAQ']

Page: 7

Motivation
mruby and mruby/c
Flashing mruby application into 128KB ROM and
running it on 128KB RAM are difficult
mruby/c runs on 64KB RAM but it doesn't have
mruby compiler
You have to compile Ruby script into VM code before
embedding

Page: 8

Motivation
MicroPython:
"Overwhelming, we are!"
「圧倒的じゃないか、我が軍は」

Page: 9

Motivation
Would it be great if we have a
smaller mruby compiler?

Page: 10

Target Microcontroller
PSoC5LP: Reference board of mruby/c
Arm Cortex-M3 32bit processor
64KB RAM
256KB ROM
It will be comparable to MicroPython if Ruby runs
on PSoC5LP with compiler

Page: 11

Demo

Page: 12

Chapter 2
Terms and Tools

Page: 13

Terms
mruby
A Ruby implementation for general embedded purpose
mrbc
The original mruby compiler bundled with mruby
mruby/c
Another implementation of mruby VM for one-chip
microcontroller
It doesn't have compiler

Page: 14

Terms
mmrbc (mini mruby compiler)
Another mruby compiler for one-chip microcontroller
mmruby (mini mruby) = mmrbc + mruby/c
mruby machine
A microcontroller embedded with integration of
mmruby, CUI shell and peripheral drivers

Page: 15

mruby machine

Page: 16

Cross compilation tools for bare metal Arm
arm-none-eabi-gcc, arm-none-eabi-ar, arm-none-
eabi-ld, arm-none-eabi-strip, etc.
What is "arm-none-eabi-" ?
arm: Arm architecture
none: Without OS (Bare metal)
eabi: Embedded Application Binary Interface

Page: 17

Three tool-chains in my laptop (Intel 64)
1. (x86_64-linux-gnu-)gcc
Usual compilation in daily development
2. arm-linux-gnueabi-gcc
Binary runs on QEMU (machine emulator)
3. arm-none-eabi-gcc (--with-newlib)
To make a final library archive (libmmrbc.a) for
bare metal Arm

Page: 18

Docker image
((‘tag:center’))
https://hub.docker.com/r/
hasumikin/arm-none-eabi-tools

Page: 19

C Library
glibc (GNU C Library)
Newlib
Another C library especially for embedded system
Some implementation is missed. eg) regex.c
Newlib-nano
Even smaller version of Newlib for Arm processor
Yet other libraries
EGLIBC, Clibc, sglibc, etc.

Page: 20

Chapter 3
mmrbc

Page: 21

Repo
https://github.com/hasumikin/mmruby

Page: 22

Features of mmrbc
Portable and Less dependent
Doesn't depend on mruby nor mruby/c
(To the contrary, mrbc depends on mruby itself)
Depends on only standard C library including Newlib(-
nano)
Can be integrated with both mruby and mruby/c

Page: 23

Features of mmrbc
Small (by linking to Newlib-nano)
Fits in less than 256KB ROM (including mruby/c VM
and some application code)
Runs enough on less than 128KB RAM

Page: 24

Features of mmrbc
Lemon as a parser generator instead of Yacc/Bison
Originally a parser generator of SQLite

Page: 25

Yacc/Bison
LALR(1) parser generator, typical choice of parser
generator
Yacc (Barkley Yacc)
Non-reentrant
Parser-Calls-Lexer style (CRuby and mruby use it)
Bison (Gnu Bison. Modernized version of Yacc)
Reentrant, Thread-Safe and Lexer-Calls-Parser style
(You can also select old Yacc style)

Page: 26

Lemon
Reentrant
Lexer-Calls-Parser style

Page: 27

Parser-Calls-Lexer style (Yacc)
yyparse(p);
/* in y.tab.c (generated by Yacc) */
int yyparse(parser_state *p) {
yytoken = yylex(yylval, p);
/* makes AST according as you defined */
...
goto yyhogefuga;
...
}
/* yylex() is called by parser */
int yylex(void *lval, parser_state *p) {
# Find next token and return token type
return tokenType;
}
GenerateVMCode(p->ast);

Page: 28

Lexer-Calls-Parser style (Lemon)
/* in your own Lexer */
while (hasMoreToken(rubyScript)) {
token = getToken(rubyScript);
Parse(parser, tokenType, token);
}
Parse(parser, 0, "");
/* in parse.c (generated by Lemon) */
void Parse(void *yyp, int yymajor, ...) {
/* makes AST according as you defined */
...
}
GenerateVMCode(p->ast);

Page: 29

Lemon
LALR(1) parser generator as well
Reentrant
Lexer-Calls-Parser style
Generated parser is, I'm still not sure though,
Faster than Yacc/Bison (according to its document)
Smaller code (according to someone)
Grammar syntax of parse.y is different from Yacc/
Bison

Page: 30

Lemon
https://sqlite.org/src/doc/trunk/doc/lemon.html

Page: 31

Chapter 4:
How smaller than mrbc?

Page: 32

RAM consumption
mruby's branch
`mruby3` as of August 14th

Page: 33

RAM consumption
To make things simple, both mrbc and mmrbc are
built for x86_64 architecture
using malloc() and free() of glibc
(mmrbc usually uses mrbc_alloc() to manage heap area)
Linux file system to load Ruby script
(microcontroller doesn't have file system)
As a result, we can simply compare with valgrind

Page: 34

RAM consumption
Analysis command looks like:
valgrind \
--tool=massif \
--stacks=yes \
path/to/(mrbc|mmrbc) path/to/script.rb
Showing the result:
ms_print massif.out.xxxx | less

Page: 35

RAM consumption: Case 1
Ruby code:
# hello_world.rb
puts "Hello World!"
Output:
Hello World!

Page: 36

RAM consumption: Case 1 / mrbc
--------------------------------------------------------------------------------
Command:
../mruby/build/host/bin/mrbc ./hello_world.rb
Massif arguments:
--stacks=yes
ms_print arguments: massif.out.4087
--------------------------------------------------------------------------------
KB
157.8^
#
|
#
|
#
|
#
|
#
|
@#
|
@#
|
@#
|
@@@#
|
@@:::::::::::@:::::::@ @#
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@:::::::@ :::: :: :: @: :: ::@ @#
|
:::::@:::::@: :: ::@ :::: :: :: @: :: ::@ @#
|
::::::::::::::::::::::: : @:: ::@: :: ::@ :::: :: :: @: :: ::@ @#
|
::::: ::: ::: ::: : : ::: : @:: ::@: :: ::@ :::: :: :: @: :: ::@ @#
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: ::: ::: ::: ::: : : ::: : @:: ::@: :: ::@ :::: :: :: @: :: ::@ @#
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: ::: ::: ::: ::: : : ::: : @:: ::@: :: ::@ :::: :: :: @: :: ::@ @#
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: ::: ::: ::: ::: : : ::: : @:: ::@: :: ::@ :::: :: :: @: :: ::@ @#
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: ::: ::: ::: ::: : : ::: : @:: ::@: :: ::@ :::: :: :: @: :: ::@ @#
|
: ::: ::: ::: ::: : : ::: : @:: ::@: :: ::@ :::: :: :: @: :: ::@ @#
|
: ::: ::: ::: ::: : : ::: : @:: ::@: :: ::@ :::: :: :: @: :: ::@ @#
0 +----------------------------------------------------------------------->Mi
0
3.235

Page: 37

RAM consumption: Case 1 / mmrbc
--------------------------------------------------------------------------------
Command:
../mmruby/build/host-production/bin/mmrbc ./hello_world.rb
Massif arguments:
--stacks=yes
ms_print arguments: massif.out.1652
--------------------------------------------------------------------------------
KB
11.17^
#
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@#
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@@# ::
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@@#:::::
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@
@ :@: : :: @@#:::::
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@ :::@: :@::: :::@@#:::::
|
@ :::@: :@:::@:::@@#:::::
|
@:::::@:::@:::@:::@@#:::::
|
@: :::@:::@:::@:::@@#:::::
|
::
@: :::@:::@:::@:::@@#::::::
|
::
@: :::@:::@:::@:::@@#::::::
|
:: :
@: :::@:::@:::@:::@@#::::::
|
:: :
@: :::@:::@:::@:::@@#::::::
|
::::
@: :::@:::@:::@:::@@#::::::
|
::::
@: :::@:::@:::@:::@@#::::::
|
::::
@: :::@:::@:::@:::@@#::::::
|
::::
@: :::@:::@:::@:::@@#::::::
|
::::
@: :::@:::@:::@:::@@#::::::
|
::::
::::::::::::::: @:::::@::: @: :::@:::@:::@:::@@#::::::
|
::::::::::::: :: : :::::::::@:::::@::: @: :::@:::@:::@:::@@#:::::@
0 +----------------------------------------------------------------------->ki
0
224.5

Page: 38

RAM consumption: Case 1 / mmrbc
--------------------------------------------------------------------------------
Command:
../mmruby/build/host-production/bin/mmrbc ./hello_world.rb
Massif arguments:
--stacks=yes
ms_print arguments: massif.out.1652
--------------------------------------------------------------------------------
KB
11.17^
#
|
@#
|
@@# ::
|
@@#:::::
|
@
@ :@: : :: @@#:::::
|
@ :::@: :@::: :::@@#:::::
|
@ :::@: :@:::@:::@@#:::::
|
@:::::@:::@:::@:::@@#:::::
|
@: :::@:::@:::@:::@@#:::::
|
::
@: :::@:::@:::@:::@@#::::::
|
::
@: :::@:::@:::@:::@@#::::::
|
:: :
@: :::@:::@:::@:::@@#::::::
|
:: :
@: :::@:::@:::@:::@@#::::::
|
::::
@: :::@:::@:::@:::@@#::::::
|
::::
@: :::@:::@:::@:::@@#::::::
|
::::
@: :::@:::@:::@:::@@#::::::
|
::::
@: :::@:::@:::@:::@@#::::::
|
::::
@: :::@:::@:::@:::@@#::::::
|
::::
::::::::::::::: @:::::@::: @: :::@:::@:::@:::@@#::::::
|
::::::::::::: :: : :::::::::@:::::@::: @: :::@:::@:::@:::@@#:::::@
0 +----------------------------------------------------------------------->ki
0
224.5
8888

Page: 39

RAM consumption: Case 2
Ruby code:
# idiotic_script.rb
ary = Array.new(3)
ary[0] = {a: 123e2}
ary[0][:key] = "string"
ary[1] = %w(abc ABC Hello)
ary[2] = 0x1f
ary[3] = !true
puts "my name is #{self.class}, result is #{ary[2] * ary[0][:a]}"
p ary

Page: 40

RAM consumption: Case 2
Output:
my name is Object, result is 381300
[{:a=>12300, :key=>"string"}, ["abc", "ABC", "Hello"], 31, false]

Page: 41

RAM consumption: Case 2 / mrbc
--------------------------------------------------------------------------------
Command:
../mruby/build/host/bin/mrbc ./idiotic_script.rb
Massif arguments:
--stacks=yes
ms_print arguments: massif.out.4133
--------------------------------------------------------------------------------
KB
162.9^
##
|
#
|
@#
|
@#
|
@#
|
@#
|
@:@#
|
@:@#
|
@:@# :
|
:::@@::::::@@@@:@# :
|
:::::::@::::::::::@ :: :::@ @:@# :
|
::::@@:::::@ :: ::@:: ::: :::@ :: :::@ @:@# :
|
::::::::::::: :@ :::: @ :: ::@:: ::: :::@ :: :::@ @:@# :
|
::::::::::::: :: :: ::: :@ :::: @ :: ::@:: ::: :::@ :: :::@ @:@# :
|
:: :::: ::::: :: :: ::: :@ :::: @ :: ::@:: ::: :::@ :: :::@ @:@# :
|
:: :::: ::::: :: :: ::: :@ :::: @ :: ::@:: ::: :::@ :: :::@ @:@# :
|
:: :::: ::::: :: :: ::: :@ :::: @ :: ::@:: ::: :::@ :: :::@ @:@# :
|
:: :::: ::::: :: :: ::: :@ :::: @ :: ::@:: ::: :::@ :: :::@ @:@# :
|
:: :::: ::::: :: :: ::: :@ :::: @ :: ::@:: ::: :::@ :: :::@ @:@# :
|
:: :::: ::::: :: :: ::: :@ :::: @ :: ::@:: ::: :::@ :: :::@ @:@# :
0 +----------------------------------------------------------------------->Mi
0
3.470

Page: 42

RAM consumption: Case 2 / mmrbc
--------------------------------------------------------------------------------
Command:
../mmruby/build/host-production/bin/mmrbc idiotic_script.rb
Massif arguments:
--stacks=yes
ms_print arguments: massif.out.13414
--------------------------------------------------------------------------------
KB
53.20^
#
|
#
|
@# :::
|
@# : :
|
@# : :
|
@@# : :
|
@@# :: :
|
@@#::: :
|
@@#::: :
|
@@::@@#::: :
|
@@: @@#::: :
|
@@:@:::@::::@@: @@#::: ::
|
@::@::@ :@:: @:: :@@: @@#::: ::
|
@:::@@@:@::@: @ :@:: @:: :@@: @@#::: ::
|
@@:@::@:: @@ :@::@: @ :@:: @:: :@@: @@#::: ::
|
::@@@ :@: @:: @@ :@::@: @ :@:: @:: :@@: @@#::: ::
|
:::::: :::::@ @ :@: @:: @@ :@::@: @ :@:: @:: :@@: @@#::: ::
|
:::::@@:: :::::: ::@ @ :@: @:: @@ :@::@: @ :@:: @:: :@@: @@#::: ::
|
: :: @ :: :::::: ::@ @ :@: @:: @@ :@::@: @ :@:: @:: :@@: @@#::: ::
|
: :: @ :: :::::: ::@ @ :@: @:: @@ :@::@: @ :@:: @:: :@@: @@#::: ::
0 +----------------------------------------------------------------------->Mi
0
1.616

Page: 43

RAM consumption: Summary
━━━━━━━━━━┳━━━━━┳━━━━━
Ruby script
┃ mrbc ┃ mmrbc
━━━━━━━━━━╋━━━━━╋━━━━━
hello_world.rb
┃ 157.8KB ┃ 11.17KB
━━━━━━━━━━╋━━━━━╋━━━━━
idiotic_script.rb ┃ 162.9KB ┃ 53.20KB
━━━━━━━━━━┻━━━━━┻━━━━━
Note: These results are larger than possible results on
32bit architecture because of pointer size

Page: 44

Idiotic script
# idiotic_script.rb
ary = Array.new(3)
ary[0] = {a: 123e2}
ary[0][:key] = "string"
ary[1] = %w(abc ABC Hello)
ary[2] = 0x1f
ary[3] = !true
puts "my name is #{self.class}, result is #{ary[2] * ary[0][:a]}"
p ary
=>
my name is Object, result is 381300
[{:a=>12300, :key=>"string"}, ["abc", "ABC", "Hello"], 31, false]
Syntax that mmrbc can compile

Page: 45

Syntax
implemented
lvar, $gvar, @ivar, CONSTANT
assignment, fcall, method chain
Literals: Array, Hash, String, Fixnum, Float, etc.
Keywords: true, false, nil, return, self, etc.
+, -, *, /, %, **, +=, -=, *=, /=, %=, &=, |=, ^=, **=, <<=, >>=
!, ~, +, -, not, &, |, ^, <<, >>
Syntax sugar: %w(a b c)
Interpolation: "The answer is #{get_result(@attr)}!"

Page: 46

Syntax
under construction
if then elif else end, unless
case when else then
while, until, break, next, redo, retry, for in
[0,1].each do |var| end
def method_name(arg); end
class MyClass < ParentClass; end
rescue, ensure
..., etc.

Page: 47

Roadmap
https://github.com/hasumikin/mmruby/issues/6

Page: 48

Code size (to estimate ROM consumption)
% ls -l
(...)
.rwxrwxrwx
.rwxrwxrwx
.rwxrwxrwx
.rwxrwxrwx
609k
903k
650k
425k
hasumi
hasumi
hasumi
hasumi
17
17
17
17
Aug
Aug
Aug
Aug
7:03
7:03
7:03
7:03
mruby_machine_PSoC5LP.a
mruby_machine_PSoC5LP.elf
mruby_machine_PSoC5LP.hex
mruby_machine_PSoC5LP.map
% size mruby_machine_PSoC5LP.elf
text
data
bss
dec
hex filename
136080
320 63009 199409 30af1 mruby_machine_PSoC5LP.elf

Page: 49

Code size (to estimate ROM consumption)
% ls -l
(...)
.rwxrwxrwx
.rwxrwxrwx
.rwxrwxrwx
.rwxrwxrwx
609k
903k
650k
425k
hasumi
hasumi
hasumi
hasumi
17
17
17
17
Aug
Aug
Aug
Aug
7:03
7:03
7:03
7:03
mruby_machine_PSoC5LP.a
mruby_machine_PSoC5LP.elf
mruby_machine_PSoC5LP.hex
mruby_machine_PSoC5LP.map
% size mruby_machine_PSoC5LP.elf
text
data
bss
dec
hex filename
136080
320 63009 199409 30af1 mruby_machine_PSoC5LP.elf
136_080 ＋ 320 ＝ 136_400 ≒ 133.2KB

Page: 50

Summary
mmrbc is a mini mruby compiler
VM code runs on both mruby VM and mruby/c VM
Still incomplete regarding syntax and memory
efficiency
mruby machine
= mmrbc + mruby/c + shell + dirivers
Runs on PSoC5LP { RAM: 64KB, ROM: 256KB }