Hello Karel, Gedare Reading the post by Pavel in the other thread, I think the pc386 shouldn't be using the libbsd framebuffer. To be able to use the driver in pc386, you'll have to disable the drivers from rtems-littevgl. Please use `--no-drivers` option with ./waf configure in rtems-littlevgl and remove the "fbdev_init" from the hello app. The initialization of the fb is supposed to be handled by the drivers in the BSP.
Best regards, Vijay On Mon, Sep 21, 2020 at 9:47 PM Gedare Bloom <ged...@rtems.org> wrote: > > Hi Karel, > > I don't know if I can provide any answers, but I can provide some > guidance maybe. I implemented mmap() in rtems to provide portability > and compliance for mmap applications that use MAP_SHARED with fixed > addresses. We don't do any real mapping or translating of memory since > there is no virtual memory support in rtems. Kevin Kirsepl > extended/fixed the file handler part of that implementation > > There is an mmap helper implemented in libbsd: rtems-libbsd.git: > /rtemsbsd/sys/fs/devfs/devfs_devs.c:391 devfs_imfs_mmap() > Vijay implemented that as part of the BBB framebuffer work. I haven't > studied it closely enough to give any advice on how to replicate/use > that in another FB. Hopefully he may be able to chime in, as he also > did a lot of the work with lvgl porting. > > The pc386 FB was written by one of Pavel Pisa's students, Jan Dolezal. > I had hopes we could generalize the code to other targets because it > is relatively simple compared to other framebuffers. I think someone > tried with raspberry pi. But that effort hasn't really moved in a few > years. > > My guess is that the pc386 fb needs to have something like devfs_imfs_mmap(). > > Gedare > > On Sun, Sep 20, 2020 at 2:43 PM Karel Gardas <karel.gar...@centrum.cz> wrote: > > > > > > Hello, > > > > I'm attempting to get rtems-example/lvgl/hello working on pc686 BSP. I'm > > using VESA framebuffer which is default on pc686, although I needed to > > do few fixes here and there to ensure littlevgl library compiles well. > > All patches here > > https://lists.rtems.org/pipermail/devel/2020-September/062186.html > > > > Now, everthing is compiled and VESA fb is well initialized -- or seems > > so. Now, vgl library tries to use that fb (/dev/fb0) and basically tries > > to mmap it for its own use. The code looks: > > > > void fbdev_init(void) > > { > > // Open the file for reading and writing > > fbfd = open(FBDEV_PATH, O_RDWR); > > if(fbfd == -1) { > > perror("Error: cannot open framebuffer device"); > > return; > > } > > printf("The framebuffer device was opened successfully.\n"); > > [...] > > // Map the device to memory > > fbp = (char *)mmap(0, screensize, PROT_READ | PROT_WRITE, > > MAP_SHARED, fbfd, 0); > > if((intptr_t)fbp == -1) { > > perror("Error: failed to map framebuffer device to memory"); > > return; > > } > > memset(fbp, 0, screensize); > > > > printf("The framebuffer device was mapped to memory successfully.\n"); > > > > > > The mmap above fails. Screensize is realistic and good looking number. > > > > While debugging this mmap I see it fails on the call to function on line > > 280: > > > > err = (*iop->pathinfo.handlers->mmap_h)( > > iop, &mapping->addr, len, prot, off ); > > > > it returns -1 and hence mmap failure since code below looks: > > > > if ( err != 0 ) { > > mmap_mappings_lock_release( ); > > free( mapping ); > > return MAP_FAILED; > > } > > > > when I try to step into the problematic function above, I end up in > > default_mmap.c:31 on: > > > > rtems_set_errno_and_return_minus_one( ENOTSUP ); > > > > and as the function claims it really returns -1 to me. > > > > Now, my obvious question is: how to make VESA fb mmappable? It looks > > like the same library is working fine on BBB while using FreeBSD BBB > > framebuffer driver, so there is probably some way how to convince RTEMS > > mmap to work with fb0. > > > > Any idea how to proceed with this is highly appreciated. > > > > Thanks, > > Karel > > > > > > _______________________________________________ > > users mailing list > > users@rtems.org > > http://lists.rtems.org/mailman/listinfo/users _______________________________________________ users mailing list users@rtems.org http://lists.rtems.org/mailman/listinfo/users
