#include <stdio.h> #include <fcntl.h> #include <unistd.h> #include <sys/mman.h> #include <drm_fourcc.h> #include <xf86drm.h> #include <xf86drmMode.h> int main() PROT_WRITE, MAP_SHARED, fd, map.offset);
gcc kms_hello.c -ldrm -o kms_hello sudo chvt 2 # Switch to a free VT sudo ./kms_hello Add libinput to read mouse events and move a rectangle around the screen. Congratulations, you just wrote a micro-compositor. Project 2: Intercept and Inspect GEM Buffer Handles Goal: Trace which process is leaking GPU memory by hooking into the Graphics Execution Manager (GEM) via ftrace or a custom LD_PRELOAD library. Hands On Projects For The Linux Graphics Subsystem
// Draw a simple gradient for (int y = 0; y < create.height; y++) for (int x = 0; x < create.width; x++) pixels[y * create.pitch / 4 + x] = (x * 255 / create.width) #include <stdio
Now go make your screen glitch in interesting ways. // Draw a simple gradient for (int y = 0; y < create
Once you’ve fixed a bug in your tinkering, send a patch to the dri-devel mailing list. The maintainers are harsh but fair – and desperately need people who have actually run their code on real hardware.