Problem with the framebuffer on an ARM device
I installed Qt Embedded on a ARM device with linux.
There is a problem with the framebuffer.
Running a simple application (./application -qws) it returns:
@Cannot create semaphore /tmp/qtembedded-0/QtEmbedded-0 'd'
Error 38 Function not implemented
Cannot get display lock
but when I try to run the framebuffer example application it returns
@The framebuffer device was opened successfully.
Fixed screen info: id: imapfb smem_start: 0x44800000 smem_len: 4718592 type: 0 type_aux: 0 visual: 2 xpanstep: 0 ypanstep: 1 ywrapstep: 0 line_length: 2048 mmio_start: 0x20cd0000 mmio_len: 16384 accel: 0 The framebuffer device was mapped to memory successfully. Successfully switched to graphics mode. Variable screen info: xres: 1024 yres: 576 xres_virtual: 1024 yres_virtual: 1152 yoffset: 0 xoffset: 0 bits_per_pixel: 16 grayscale: 0 red: offset: 11, length: 5, msb_right: 0 green: offset: 5, length: 6, msb_right: 0 blue: offset: 0, length: 5, msb_right: 0 transp: offset: 0, length: 0, msb_right: 0 nonstd: 0 activate: 0 height: 0 width: 0 accel_flags: 0x0 pixclock: 46213560 left_margin: 128 right_margin: 15 upper_margin: 21 lower_margin: 5 hsync_len: 104 vsync_len: 4 sync: 0 vmode: 0 Frame Buffer Performance test... Average: 39244 usecs Bandwidth: 114.667 MByte/Sec Max. FPS: 25.482 fps Will draw 3 rectangles on the screen, they should be colored red, green and blue (in that order). Done.@
How can I solve?
I changed the permission to the file /tmp/qtembedded-0/QtEmbedded-0 but it returns a "wrong permissions" error
Thank you in advance for your help. I spent the last 3 days around this problem
When you launch the framebuffer example, did you have the three rectangle on the screen?
Have you write permission on your partition including the /tmp directory? Perhaps this partition is read-only? What the result of "mount" command?
Thank you very much ngrosjean for you replay.
I'm very disperate!
When I launch the framebuffer example there are the three rectangles on the screen in the right order and the output is written in my previous post.
I tried to change the permissions on /tmp directory. /tmp is a link to /var/tmp so I changed the permission on /tmp/var.
When I try to run another example after changed the permission the system returns a "wrong permissions" error.
This evening I'll try the mount command and I'll post a replay.
Thank you again
I have recently had the same problem. Turned out that I had to include System V IPC option in the kernel.