Create separate renderer and framebuffer modules

fb.c

@@ -0,0 +1,49 @@
+#include "fb.h"
+
+#include <assert.h>
+#include <sys/ioctl.h>
+#include <sys/mman.h>
+
+fb_info_t fb_init(int drm_fd, drmModeModeInfo mode)
+{
+	int err;
+
+	struct drm_mode_create_dumb create = {
+		.width = mode.hdisplay,
+		.height = mode.vdisplay,
+		.bpp = 32,
+	};
+	err = ioctl(drm_fd, DRM_IOCTL_MODE_CREATE_DUMB, &create);
+	assert(err != -1);
+
+	uint32_t id;
+	err = drmModeAddFB(
+	    drm_fd, create.width, create.height, 24, 32, create.pitch,
+	    create.handle, &id);
+	assert(err == 0);
+
+	struct drm_mode_map_dumb map = { .handle = create.handle };
+	err = ioctl(drm_fd, DRM_IOCTL_MODE_MAP_DUMB, &map);
+	assert(err != -1);
+
+	uint32_t *buf = mmap(
+	    0, create.size, PROT_READ | PROT_WRITE, MAP_SHARED, drm_fd,
+	    map.offset);
+	assert(buf != MAP_FAILED);
+
+	return (fb_info_t) {
+		.buf = buf,
+		.handle = create.handle,
+		.id = id,
+		.pitch = create.pitch,
+		.size = create.size,
+	};
+}
+
+void fb_cleanup(int drm_fd, fb_info_t fb)
+{
+	munmap(fb.buf, fb.size);
+	drmModeRmFB(drm_fd, fb.id);
+	struct drm_mode_destroy_dumb delete = { .handle = fb.handle };
+	ioctl(drm_fd, DRM_IOCTL_MODE_DESTROY_DUMB, &delete);
+}