ret = drmIoctl(fd, DRM_IOCTL_MODE_MAP_DUMB, &mreq); if (ret) { fprintf(stderr, "cannot map dumb buffer (%d): %m\n", errno); ret = -errno; goto err_fb; } /* perform actual memory mapping */ dev->map = mmap(0, dev->size, PROT_READ | PROT_WRITE, MAP_SHARED, fd, mreq...
struct drm_mode_map_dumb map = {}; create.width = bo->width; create.height = bo->height; create.bpp = 32; drmIoctl(fd, DRM_IOCTL_MODE_CREATE_DUMB, &create); bo->pitch = create.pitch; bo->size = create.size; bo->handle = create.handle; drmModeAddFB(fd, bo->width, bo->he...
通常在看 DRM 文档时,还会提到dumb_map_offset和dumb_destroy这两个接口,分别对应各自的 ioctl 函数。如果驱动没有实现这两个回调接口, 那么 DRM 框架会使用默认的drm_gem_dumb_map_offset()和drm_gem_dumb_destroy()代替。 为什么要执行 DRM_IOCTL_MODE_MAP_DUMB ? 许多人刚开始写 dumb buffer 应用程序时都...
struct drm_device { struct drm_mode_create_dumb create ; //创建的dumb struct drm_mode_map_dumb map; //内存映射结构体 }; static int drm_create_fb(struct drm_device *bo) { /* create a dumb-buffer, the pixel format is XRGB888 */ bo->create.width = bo->width; bo->create.height...
drmIoctl(fd, DRM_IOCTL_MODE_DESTROY_DUMB, &dreq); return ret; } 以上代码新建了一个Dumb方式的framebuffer并且映射到用户空间,用户空间可以直接操作framebuffer。步骤如下: 1.新建Dumb对象。 2.Dumb新建frambuffer 对象。 3.通过 DRM_IOCTL_MODE_MAP_DUMB 来获取DUMB的 offset。
准备map: /* prepare buffer for memory mapping */memset(&mreq,0,sizeof(mreq));mreq.handle=dev->handle;ret=drmIoctl(fd,DRM_IOCTL_MODE_MAP_DUMB,&mreq);if(ret){fprintf(stderr,"cannot map dumb buffer (%d): %m\n",errno);ret=-errno;gotoerr_fb;}...
struct drm_mode_map_dumb arg; void *map; int ret; memset(&arg, 0, sizeof(arg)); arg.handle = bo->handle; ret = drmIoctl(fd, DRM_IOCTL_MODE_MAP_DUMB, &arg); if (ret) return ret; map = drm_mmap(0, bo->size, PROT_READ | PROT_WRITE, MAP_SHARED, fd, arg.offset); ...
准备map: /* prepare buffer for memory mapping */memset(&mreq,0,sizeof(mreq));mreq.handle=dev->handle;ret=drmIoctl(fd,DRM_IOCTL_MODE_MAP_DUMB,&mreq);if(ret){fprintf(stderr,"cannot map dumb buffer (%d): %m\n",errno);ret=-errno;gotoerr_fb;} ...
!has_dumb) {fprintf(stderr,"drm device '%s' does not support dumb buffers\n", node);close(fd);return-EOPNOTSUPP; } 检索Resource Resource的获取需要两次,第一次,获取数量大小,第二次才真正获取具体的Resource。具体看这个函数: drmModeResPtrdrmModeGetResources(intfd) ...
ret = drmIoctl(fd, DRM_IOCTL_MODE_MAP_DUMB, &mreq); if (ret) { fprintf(stderr, "cannot map dumb buffer (%d): %m\n", errno); ret = -errno; goto err_fb; } 1. 2. 3. 4. 5. 6. 7. 8. 9. 10. 做map操作: /* perform actual memory mapping */ ...