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Accessibility (Kernel): Difference between revisions

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Martijn Braam says:
Martijn Braam says:
<q>It depends on the device, of course,
<q>It depends on the device, of course,
but I don't think adding support for usb-serial adapters would be a problem.
but I don't think adding support for USB-serial adapters would be a problem.
I already did that to test some things on the PinePhone.
I already did that to test some things on the PinePhone.
I guess enabling prolific, ftdi, and ch340 would cover most adapter cables.
I guess enabling prolific, ftdi, and ch340 would cover most adapter cables.
Unfortunately, it would be a per-device kernel tweak.
Unfortunately, it would be a per-device kernel tweak.
I'm not sure how much devices have usb serial support built in already.
I'm not sure how many devices have USB serial support built in already.
The allwinner kernel only has CH341 support currently.
The allwinner kernel only has CH341 support currently.
It looks like the generic driver is 14.4KB and ch341 adds 4.7KB.
It looks like the generic driver is 14.4KB and ch341 adds 4.7KB.
Serial drivers aren't really big...</q>
Serial drivers aren't really big...
(The drivers are all listed under drivers/usb/serial in the kconfig utility.)</q>


=== Virtual Console ===
=== Virtual Console ===
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between multiple virtual consoles to access unrelated user interfaces.</q>
between multiple virtual consoles to access unrelated user interfaces.</q>


Virtual console support (CONFIG_VT) is required to boot pmOS.
Virtual console support
([[Kernel configuration#CONFIG_VT|CONFIG_VT]]) is required to boot pmOS.
So, it ''should'' be supported on any device running the [[The_Mainline_Kernel|mainline kernel]].
So, it ''should'' be supported on any device running the [[The_Mainline_Kernel|mainline kernel]].
That said, problems have been reported (e.g., with version 4.4).
That said, problems have been reported (e.g., with version 4.4).
== Resources ==
*  [[Kernel configuration]] - detailed config information for pmOS

Revision as of 17:11, 22 August 2020

Introduction

In order to support accessibility packages, some kernel modifications may be needed. Some of these can be made at the level of Alpine Linux or pmOS; others will need to be made separately for each supported device.

Modifications

Serial Adapters

Dave Mielke (BRLTTY's developer) says: It'd be very cool for the kernel to have support for all known USB-to-serial adapters, plus any indirectly needed serial support, enabled. That way, those with older braille devices that only have a serial port would benefit for the mere extra cost of the adapter cable. Sure would beat having to purchase a newer braille device.

Martijn Braam says: It depends on the device, of course, but I don't think adding support for USB-serial adapters would be a problem. I already did that to test some things on the PinePhone. I guess enabling prolific, ftdi, and ch340 would cover most adapter cables. Unfortunately, it would be a per-device kernel tweak. I'm not sure how many devices have USB serial support built in already. The allwinner kernel only has CH341 support currently. It looks like the generic driver is 14.4KB and ch341 adds 4.7KB. Serial drivers aren't really big... (The drivers are all listed under drivers/usb/serial in the kconfig utility.)

Virtual Console

Many forms of assistive technology make use of a virtual console:

A virtual console (VC) – also known as a virtual terminal (VT) – is a conceptual combination of the keyboard and display for a computer user interface. It is a feature of some Unix-like operating systems such as BSD, Linux, illumos and UnixWare in which the system console of the computer can be used to switch between multiple virtual consoles to access unrelated user interfaces.

Virtual console support (CONFIG_VT) is required to boot pmOS. So, it should be supported on any device running the mainline kernel. That said, problems have been reported (e.g., with version 4.4).

Resources