drm_gem_fb_create(9)

📦 version 7.3.1, in nixpkgs unstable

💅 drm_gem_fb_create — kernel API manual, bestie edition ✨

Okay so real talk, this is drm_gem_fb_create(9) from the Kernel API Manual, and it's genuinely one of those little helper functions that just gets it. Let's go 🫶

✨ NAME ✨

drm_gem_fb_create — the helper function for your &drm_mode_config_funcs.fb_create callback. That's the whole vibe. She's a helper, she's a callback plug-in, she's iconic 💖

🎀 SYNOPSIS 🎀

struct drm_framebuffer * drm_gem_fb_create (struct drm_device *dev ,
   struct drm_file *file , const struct drm_format_info *info , const
   struct drm_mode_fb_cmd2 *mode_cmd );

Like, look at her signature. Four args, one framebuffer pointer coming back at you. Periodt ⭐

🌸 ARGUMENTS 🌸

  • dev — the DRM device. Main character energy, obviously 👑
  • file — the DRM file that holds the GEM handle(s) backing the framebuffer. She's the one holding the handles, iykyk 🫶
  • info — pixel format information. All the format deets live here 🎀
  • mode_cmd — metadata straight from the userspace framebuffer creation request. Handed over by userspace, no cap 💅

🦋 DESCRIPTION 🦋

So this function creates a brand-new framebuffer object, and that object is described by drm_mode_fb_cmd2. And that description? It includes the handles for the buffer(s) backing the framebuffer. Like, handles included, bestie, that's the whole point 💖

If your hardware has special alignment or pitch requirements, lowkey you have to check those before calling this function — she's not doing that for you. What she does do is buffer size validation, and she does it. Use drm_gem_fb_create_with_dirty if you need framebuffer flushing instead 🔥

Drivers can totally use this as their drm_mode_config_funcs.fb_create callback. And the ADDFB2 IOCTL calls into this callback. That's the pipeline, and she ate 🌈

💀 RETURN 💀

  • A pointer to a drm_framebuffer on success xoxo ✨
  • Or an error pointer on failure 🙈 (check it, don't ignore it, fr fr)

🧚 SEE ALSO 🧚

Go read the Kernel file ./drivers/gpu/drm/drm_gem_framebuffer_helper.c overview(9) for the full lore, plus all her besties:

💀 one thing before you dip: everything above is from ./drivers/gpu/drm, dated October 2026, and the page itself is drm_gem_fb_create(9). Slay, bye 🎀✨💜
📦 where this page comes from