8227425: Add support for e-paper displays on i.MX6 devices

[jgneff]

This is a request to add support for e-paper displays with the i.MX 6 Series of Applications Processors. It's a follow-up request to Issue #339, "Add support for e-paper displays," which was implemented by Pull Request #369.

Report Classification

Issue Type: Request for Enhancement
Component: JavaFX
Subcomponent: graphics: JavaFX Graphics
Operating System: Ubuntu
Java Release: 13

Report Details

Synopsis

Add support for e-paper displays on i.MX6 devices

Description

This request follows up on the plans in Issue #339 which stated:

Once the implementation is stable, other more powerful models can be added, such as the Kobo Glo HD with an i.MX6SL processor and the Kobo Clara HD with an i.MX6SLL processor, each based on the ARM Cortex-A9 core.

While Pull Request #369 added support for the two oldest e-reader models still being updated by Kobo, the Kobo Touch B and C, this is a request to add support for two more recent models. The following sections provide details on the new device models, new NXP processors, and new Ubuntu releases to be supported.

New device models

The following table lists the device characteristics and Linux kernel versions of all four models. The SD column is the storage size of the internal microSD card. The new models to be supported are shown in boldface type.

Year	Product Name	CPU	Screen (px)	RAM (MiB)	SD (GB)	Kernel
2012	Kobo Touch B	i.MX507	800 × 600	256	2	2.6.35
2013	Kobo Touch C	i.MX507	800 × 600	256	2	2.6.35
2015	Kobo Glo HD	i.MX6SL	1448 × 1072	512	4	3.0.35
2018	Kobo Clara HD	i.MX6SLL	1448 × 1072	512	8	4.1.15

New NXP processors

The following table lists the features of the NXP processors that include an e-paper display controller. There are not yet any Kobo e-readers with the i.MX7D processor. The new processors to be supported by this request are shown in boldface type.

CPU	Frequency (GHz)	Architecture	ARM Core	Memory Bus (MHz)
i.MX507	0.8	ARMv7-A	Cortex-A8	266
i.MX6SL	1.0	ARMv7-A	Cortex-A9	400
i.MX6SLL	1.0	ARMv7-A	Cortex-A9	400
i.MX7D	2 × 1.2	ARMv7-A	Cortex-A7	533

New Ubuntu releases

The following table lists the minimum kernel version required by recent Long Term Support (LTS) releases of Ubuntu and the version of the C library they contain (/lib/arm-linux-gnueabihf/libc-2.XX.so). It also shows the initial install size of each release and the total number of packages available. The new Ubuntu releases to be tested with this request are shown in boldface type.

Ubuntu Release	Minimum Kernel	C Library	Size (MB)	Packages
14.04 LTS	2.6.32	2.19	190	46,273
16.04 LTS	3.2.0	2.23	109	54,520
18.04 LTS	3.2.0	2.27	55	59,624

All of the Kobo e-readers can run Ubuntu 14.04 LTS. The Kobo Clara HD has a more recent Linux kernel (version 4.1.15), which allows it to run Ubuntu 16.04 LTS and Ubuntu 18.04 LTS.

Ubuntu 18.04 LTS includes OpenJDK 11, the minimum version required for the latest JavaFX SDK. The other Ubuntu releases use the arm32 build of OpenJDK 13 from AdoptOpenJDK, which requires a minimum C library version of 2.15. (The download page states that it requires "glibc version 2.17 or higher," but the highest version I can find in the build is GLIBC_2.15 for lib/libjava.so.)

All device models

To put this request in perspective, the following table lists all of the e-readers still being updated by Kobo. The devices are grouped by their hardware class, known as the Mark Number. Only the Mark 7 models are still for sale as new, although other models can be found used or refurbished. The four models to be tested are shown in boldface type with the JavaFX version in which the support was added or is expected.

Hardware	Code Name	Model	ID	Product Name	JavaFX
Mark 3	trilogy	N905B	310	Kobo Touch B	13
Mark 4	trilogy	N905C	320	Kobo Touch C	13
	kraken	N613	330	Kobo Glo
	pixie	N705	340	Kobo Mini
	dragon	N204B	350	Kobo Aura HD
Mark 5	phoenix	N514	360	Kobo Aura
	dahlia	N250	370	Kobo Aura H20
Mark 6	alyssum	N437	371	Kobo Glo HD	14
	pika	N587	372	Kobo Touch 2.0
	daylight	N709	373	Kobo Aura ONE
	snow	N867	374	Kobo Aura H2O Edition 2 v1
	star	N236	375	Kobo Aura Edition 2 v1
	daylight	N709	381	Kobo Aura ONE Limited Edition
Mark 7	nova	N249	376	Kobo Clara HD	14
	snow	N867	378	Kobo Aura H2O Edition 2 v2
	star	N236	379	Kobo Aura Edition 2 v2
	frost	N782	380	Kobo Forma
	storm	N873	384	Kobo Libra H2O

System / OS / Java Runtime Information

The system configuration of the two new devices is listed below. The screen on both models is a 6-inch E Ink Carta display panel with a resolution of 1448 × 1072 pixels and a density of 300 pixels per inch, supporting up to 16 levels of gray (4-bit grayscale).

Kobo Glo HD

The Kobo Glo HD has a 1.0 GHz i.MX6SL Multimedia Application Processor and 512 MB of RAM. This processor has an ARM Cortex-A9 core implementing the ARMv7-A architecture. The system runs Ubuntu Base 14.04.6 LTS (Trusty Tahr) in a chroot environment.

ubuntu@glohd1:~$ uname -a
Linux glohd1 3.0.35+ #4072 PREEMPT
Mon Dec 19 09:25:37 CST 2016 armv7l armv7l armv7l GNU/Linux

ubuntu@glohd1:~$ ldd --version
ldd (Ubuntu EGLIBC 2.19-0ubuntu6.15) 2.19

ubuntu@glohd1:~$ getconf GNU_LIBPTHREAD_VERSION
NPTL 2.19

ubuntu@glohd1:~$ ~/opt/jdk-13.0.1+9/bin/java -version
openjdk version "13.0.1" 2019-10-15
OpenJDK Runtime Environment AdoptOpenJDK (build 13.0.1+9)
OpenJDK Server VM AdoptOpenJDK (build 13.0.1+9, mixed mode)

Kobo Clara HD

The Kobo Clara HD has a 1.0 GHz i.MX6SLL Multimedia Application Processor and 512 MB of RAM. This processor has an ARM Cortex-A9 core implementing the ARMv7-A architecture. The system runs Ubuntu Base 14.04.6 LTS (Trusty Tahr), Ubuntu Base 16.04.6 LTS (Xenial Xerus), and Ubuntu Base 18.04.3 LTS (Bionic Beaver), each in a chroot environment.

Ubuntu 14.04 LTS

ubuntu@clarahd:~$ uname -a
Linux clarahd 4.1.15-00084-gcd0d3a4 #29 SMP PREEMPT
Wed Nov 21 11:31:06 CST 2018 armv7l armv7l armv7l GNU/Linux

ubuntu@clarahd:~$ ldd --version
ldd (Ubuntu EGLIBC 2.19-0ubuntu6.15) 2.19

ubuntu@clarahd:~$ getconf GNU_LIBPTHREAD_VERSION
NPTL 2.19

ubuntu@clarahd:~$ ~/opt/jdk-13.0.1+9/bin/java -version
openjdk version "13.0.1" 2019-10-15
OpenJDK Runtime Environment AdoptOpenJDK (build 13.0.1+9)
OpenJDK Server VM AdoptOpenJDK (build 13.0.1+9, mixed mode)

Ubuntu 16.04 LTS

ubuntu@clarahd:~$ uname -a
Linux clarahd 4.1.15-00084-gcd0d3a4 #29 SMP PREEMPT
Wed Nov 21 11:31:06 CST 2018 armv7l armv7l armv7l GNU/Linux

ubuntu@clarahd:~$ ldd --version
ldd (Ubuntu GLIBC 2.23-0ubuntu11) 2.23

ubuntu@clarahd:~$ getconf GNU_LIBPTHREAD_VERSION
NPTL 2.23

ubuntu@clarahd:~$ ~/opt/jdk-13.0.1+9/bin/java -version
openjdk version "13.0.1" 2019-10-15
OpenJDK Runtime Environment AdoptOpenJDK (build 13.0.1+9)
OpenJDK Server VM AdoptOpenJDK (build 13.0.1+9, mixed mode)

Ubuntu 18.04 LTS

ubuntu@clarahd:~$ uname -a
Linux clarahd 4.1.15-00084-gcd0d3a4 #29 SMP PREEMPT
Wed Nov 21 11:31:06 CST 2018 armv7l armv7l armv7l GNU/Linux

ubuntu@clarahd:~$ ldd --version
ldd (Ubuntu GLIBC 2.27-3ubuntu1) 2.27

ubuntu@clarahd:~$ getconf GNU_LIBPTHREAD_VERSION
NPTL 2.27

ubuntu@clarahd:~$ java -version
openjdk version "11.0.4" 2019-07-16
OpenJDK Runtime Environment (build 11.0.4+11-post-Ubuntu-1ubuntu218.04.3)
OpenJDK Server VM (build 11.0.4+11-post-Ubuntu-1ubuntu218.04.3, mixed mode)

[jgneff]

JBS bug ID: https://bugs.openjdk.java.net/browse/JDK-8227425

[jgneff]

Closed by Pull Request openjdk/jfx#60.

Note that Ubuntu Base 20.04 LTS (Focal Fossa) was added to the list of new Ubuntu releases tested on the Kobo Clara HD. Below is the updated table for "New Ubuntu releases."

Ubuntu Release	Minimum Kernel	C Library	Size (MB)	Packages
14.04 LTS	2.6.32	2.19	190	46,273
16.04 LTS	3.2.0	2.23	109	54,520
18.04 LTS	3.2.0	2.27	55	59,624
20.04 LTS	3.2.0	2.31	60	57,516