Odilia on Linux mobile devices

[C-Loftus]

I am very excited at the prospect of Odilia on Linux mobile devices. I feel that as of now, screen readers which exist on mobile tend to take an all or nothing approach that totally changes how standard navigation is done. It would be amazing to have a scriptable, lightweight screen reader that could be customized to fit a variety of user personas.

TLDR

These are some preliminary tests from my tinkering. It seems to start fine, but postmarketOS/alpine is just missing some dependencies for a11y stuff so there are runtime issues I am unable to figure out. Still cool to tinker with though and it is promising.

Version

I am using a standard pinephone, not the pro model, with phosh and postmarketOS.

pine64-pinephone:~$ uname -a
Linux pine64-pinephone 6.12.1 #2-postmarketos-allwinner SMP PREEMPT Sat Dec 21 00:33:52 UTC 20 aarch64 Linux

Building

Someone who is more experienced at Rust than I am may provide better insight on this, but I found this build to work.

Add to ~/.cargo/config (I think this is needed to explicitly use the gcc linker?)

[target.aarch64-unknown-linux-musl]
linker = "aarch64-linux-gnu-gcc"

Then add the target and cross compile.

rustup target add aarch64-unknown-linux-musl
RUSTFLAGS="-C link-arg=-lgcc" cargo build --target=aarch64-unknown-linux-musl --release

I needed to add that link-arg explicitly in the cargo build command since otherwise it failed. Not sure why.

I then can run scp target/aarch64-unknown-linux-musl/release/odilia user@172.16.42.1:/home/user to copy Odilia to my home dir and run it on the phone.

Running

Dependencies

speech-dispatcher needs to be installed manually but is easy to do since its in alpine repos. Once that is started spd-say works and says the text passed in, but for some reason the shell command itself hangs and never terminates.

at-spi needs to be installed likewise by running apk add at-spi2-core.

Running Odilia Itself

The Odilia binary itself works but it seems to have issues connecting to the at-spi bus. I confirmed that dbus and at-spi were running with pgrep.

pine64-pinephone:~$ pgrep -fl at-spi
4594 /usr/libexec/at-spi-bus-launcher
4600 /usr/bin/dbus-daemon
4619 /usr/libexec/at-spi2-registryd

pine64-pinephone:~$ ./odilia 
Error: Could not connect to at-spi bus

Caused by:
   0: I/O error: No such file or directory (os error 2)
   1: No such file or directory (os error 2)

Location:
    odilia/src/state.rs:146:14

[TTWNO]

Once that is started spd-say works and says the text passed in, but for some reason the shell command itself hangs and never terminates.

Interesting.... I wonder if that can be tracked down... Consider opening an issue against speechd and see if Samuel might know something about this.

pine64-pinephone:~$ ./odilia
Error: Could not connect to at-spi bus

Caused by:
0: I/O error: No such file or directory (os error 2)
1: No such file or directory (os error 2)

Location:
odilia/src/state.rs:146:14

What is it not finding? We don't explicitly look for a file. This is probably a general DBus issue and not specific to Odilia. I wonder if the Alpine-packaged daemon doesn't open a socket or something like that by default. Check to see if you can get any zbus-based application working first—even a test/example script.

Another option is to try installing dbus-broker (another DBus daemon implementation)—since dbus-broker is the default on Arch, it eliminates another variable of difference compared to what we're running on.

If you do find out what the setup should be, let us know here and I'd be glad to add a CI job that checks that an aarch64 Alpine image works.

[TTWNO]

[target.aarch64-unknown-linux-musl]
linker = "aarch64-linux-gnu-gcc"

You are mixing GNU and musl libcs here... "-gnu-gcc" usually indicates that it depends on GNU libc, but you want musl libc. I don't expect this is your primary issue, however.