Building fbdoom

[johanburati]

I am getting an error when I try to build fbdoom on Ubuntu 20.04 x86_64.
Maybe I am missing some 16bit libraries, does anyone knows which ones I need to install ?

$ ./scripts/build_toolchain -s build_fbdoom

ARCH=i386
GCC_TC_VER=7.3.0
ARCH_GCC_TC_VER=stable-2018.11-1

CI Detected: None [Assuming user machine]
[build_toolchain] Executing single function 'build_fbdoom'
NOTE: Skipping FBDOOM
[build_toolchain] Executing single function: DONE

$ cat ./toolchain2/i386/fbDOOM/fbdoom/build.log
mkdir -p build
[Compiling i_video_fbdev.c]
[Compiling i_input_tty.c]
[Compiling i_main.c]
[Compiling dummy.c]
/tmp/tilck/scripts/build_scripts/i686-linux-gcc: 2: exec: -m32: not found
make: *** [Makefile:61: build/i_video_fbdev.o] Error 127
/tmp/tilck/scripts/build_scripts/i686-linux-gcc: 2: exec: -m32: not found
make: *** Waiting for unfinished jobs....
make: *** [Makefile:61: build/i_input_tty.o] Error 127
/tmp/tilck/scripts/build_scripts/i686-linux-gcc: 2: exec: -m32: not found
make: *** [Makefile:61: build/i_main.o] Error 127
/tmp/tilck/scripts/build_scripts/i686-linux-gcc: 2: exec: -m32: not found
make: *** [Makefile:61: build/dummy.o] Error 127

[vvaltchev]

Hi Johan!
I'm unable to reproduce your issue, not even on a fresh install of Ubuntu 20.04. build_fbdoom uses a prebuilt GCC i686 toolchain downloaded the first time ./scripts/build_toolchain is run, so there's no need to install 32-bit cross-compilers at system level.

Did you run ./scripts/build_toolchain without options first? I get a failure close enough to that, if the toolchain does not exist and the script is called with -s.

Running ./scripts/build_toolchain without options is the first step required after cloning Tilck's repo:
https://github.com/vvaltchev/tilck#building-tilck

Or, if you're interested in the long story, there's also this document:
https://github.com/vvaltchev/tilck/blob/master/docs/building.md

After that, of course, you can install additional packages using the -s option.

EDIT: installing fbDOOM in the toolchain does not automatically make it part of Tilck's image. It just makes the EXTRA_FBDOOM CMake option available. You have to enable it explicitly. Check this wiki page:
https://github.com/vvaltchev/tilck/wiki/fbDOOM-on-Tilck

The reason for this extra step is being able to keep extra packages in the toolchain, without necessarily using them for every build.

Let me know if this solves your problem :-)
Have a nice day,
Vlad

[johanburati]

Hi Vlad, thank you I've tried again and could build it this time, maybe I missed running the script without the -s option.
Now I need to figure out how to get the framebuffer thing to work with qemu, I am getting a Could not open /dev/fb0 error when trying to run fbdoom, any idea how to fix that ? Nice work btw ! 😉😉😉

[vvaltchev]

I'm happy to help :-)
You could get such an error only if you booted Tilck in "text mode". The bootloader allows you to choose text mode or plenty of other resolutions. 800x600 is the default one.

If you're using Linux, just run ./build/run_qemu and boot using the default settings by just pressing ENTER.

If you're using WSL, running Linux graphical applications (such as QEMU) is more tricky. You'd need to install an X server on Windows and then configure properly the DISPLAY environment variable in WSL. You should probably google for a generic tutorial about that, as it has nothing to do with Tilck. BTW, at some point, when WSLg will become mainstream, it would be much easier to run Linux graphics apps from WSL.

[johanburati]

Awesome it's working ! I was using the kernel and the ramdisk, I switched to using the image ;-)

[vvaltchev]

That’s great!