linux graphic drm

最新推荐文章于 2023-10-20 07:15:00 发布

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最新推荐文章于 2023-10-20 07:15:00 发布

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文章标签： linux 运维服务器

本文链接：https://blog.youkuaiyun.com/lenovo8088/article/details/127524383

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linux graphic drm

DRM设备节点

card0 controlD64 renderD128

打开设备

int fd = open("/dev/dri/card0", O_RDWR | O_CLOEXEC);

检查能力

drmIoctl(fd, DRM_IOCTL_GET_CAP, &cap)
drmGetCap(fd, DRM_CAP_DUMB_BUFFER, &has_dumb)
#DRM_CAP_ASYNC_PAGE_FLIP
#DRM_CAP_DUMB_BUFFER
#DRM_CAP_CURSOR_WIDTH
#DRM_CAP_CURSOR_HEIGHT
#DRM_CAP_TIMESTAMP_MONOTONIC

检索

drmModeResPtr drmModeGetResources(int fd)
drmModeGetResources(fd);

获取连接

drmModeConnector *conn = drmModeGetConnector(fd, res->connectors[i]);

Encoder结构

drmModeEncoder *enc = drmModeGetEncoder(fd, conn->encoder_id);
drmIoctl(fd, DRM_IOCTL_MODE_GETENCODER, &enc)

CRTC结构

struct crtc {
    drmModeCrtc *crtc;
    drmModeObjectProperties *props;
    drmModePropertyRes **props_info;
    drmModeModeInfo *mode;
};
typedef struct _drmModeCrtc {
    uint32_t crtc_id;
    uint32_t buffer_id; /**< FB id to connect to 0 = disconnect */

    uint32_t x, y; /**< Position on the framebuffer */
    uint32_t width, height;
    int mode_valid;
    drmModeModeInfo mode;

    int gamma_size; /**< Number of gamma stops */

} drmModeCrtc, *drmModeCrtcPtr;
drmIoctl(fd, DRM_IOCTL_MODE_GETCRTC, &crtc)
DRM_IOCTL(fd, DRM_IOCTL_MODE_SETCRTC, &crtc);

FrameBuffer

drmIoctl(fd, DRM_IOCTL_MODE_CREATE_DUMB, &creq);
drmModeAddFB(fd, dev->width, dev->height, 24, 32, dev->stride,dev->handle, &dev->fb);
drmIoctl(fd, DRM_IOCTL_MODE_MAP_DUMB, &mreq);
dev->map = mmap(0, dev->size, PROT_READ | PROT_WRITE, MAP_SHARED,fd, mreq.offset);