The HVM embedded Java VM For very tiny devices

Overview Hardware near programming: a case example Hardware near programming: a case example in Java Contributions of the HVM Using Java to improve SW development processes for embedded devices

A case example Target: CR16C – 16 bit platform from National – 8 Kb RAM Kb flash (ROM) – GCC available Example – Blink LED slowly and comforting, WHILE – Write simple text to UART interface (serial)

A case example Blinking LEDs, – Port 2, Pin 1 soldered to LED – From CR16c specification:

A case example Writing to UART, – Put byte in transmit register – Enable UART transmit – Clear TX interrupt – Wait for next TX interrupt – From CR16c specification:

A case example in Java Let’s look at the code……………….. Compiling for the CR16c Compiling for other platforms (ATmega2560)

Contributions of the HVM Hardware objects (Martin Schoeberl) 1st level interrupt handling (Stephan Korsholm et. al.) Intelligent class linking (as proguard treeshaker) SDK independence ROM/RAM aware Extremely portable ( gcc –nostdlib *.c )

Improving embedded SW The wedge is made up of proper tools for ensuring software quality: Test driven development, unit testing, regression testing Code review, proper design, static analysis, modeling Scrum, communication & team spirit Intelligence & technical skills are the force pushing the boulder up Destructive forces are changes…… –..in environment –..in tools –..in the physical world –..in HW –..in SW

The birds eye view We are in it for the money! – Increasing SW quality – Increasing speed of development – Increasing agility – Increasing predictability of project progress