前言

更换开机Nivida logo需要重刷bootloader中的bmp.blob文件， 以下在ubuntu18.04上位机操作。详细教程请阅读刷机时下载的一系列系统文件中的Linux_for_Tegra/tools/bmp-splash/bmp-blob-README.txt文档。更换另外几个背景在烧写环境或者设备上都可以修改。

步骤

1.制作新的开机logo图片
图像格式存为bmp。分别设置分辨率为480 720 1080，可以准备3张也可以其中任意一张， 这取决于接的显示器分辨率。

2.生成bmp.blob
切换主机路径至Linux_for_Tegra/tools/bmp-splash，将图片路径写入./config_file文件中，接着用nv提供的./BMP_generator_L4T.py脚本生成bmp.blob。需确保文件大小不要超过默认扇区大小限制。
 

laji@laji-Inspiron-560s:~/TX2-NX/Linux_for_Tegra/tools/bmp-splash$ cat bmp-blob-README.txt
-- Jetson BMP blob tool instructions --To create a Jetson-compatible BMP blob (bmp.blob) for the boot splash screen
display on Jetson boards, change to the 'Linux_for_Tegra/tools/bmp-splash'
directory and enter this command at the Linux prompt:OUT=$PWD ./genbmpblob_L4T.sh t210 ./config_file ./BMP_generator_L4T.py /usr/bin/lz4c my-bmp.blobIf you want to put the bmp.blob in a designated output directory, you
can change OUT=$PWD to OUT=, for instance ./out.Note that the 't210' parameter tells the BMP scripts to use the format that
is fully backward compatible with all CBoot versions, whether based on a T210,
T186 or T194 SoC.The config_file contains the names of the BMP files you want to provide
for CBoot to display on HDMI during boot. The standard NVIDIA bmp.blob
contains three BMPs: 1080, 720 and 480 'NVIDIA' green-on-black images.
You can replace them with one, two or three of your own BMP images,
depending on what screen resolutions you want to support. Use a normal
PC bitmap, Windows 3.x format, 24BPP. If you want to support only 1080p,
which is standard on most HDMI displays, you can provide just one entry.
Use the Linux 'file' command to make sure your BMP is an uncompressed
Windows 3.x, 24BPP BMP file. RLE, layers, etc. are not supported.The standard NVIDIA blob is compressed to save space. Specify the
location of your lz4c binary as the fourth argument to genmbpblob_l4t.sh
to have your BMP blob compressed. The lz4c tool is typically found in
the liblz4-1 package. Use 'apt-get install liblz4-1' or similar tool to
install it, typically to /usr/bin, depending on your Linux distro.You can place any BMP files you want to add to the blob in the current
directory, or you can modify the config_file to point to them. For
instance, the standard config_file example provided lists them as:nvidia480.bmp nvidia 480;
nvidia720.bmp nvidia 720;
nvidia1080.bmp nvidia 1080[Note that all lines but the last should end with a semi-colon]You can point to your BMP files with an absolute or relative path:./bmp/my480.bmp nvidia 480;
./bmp/my1080.bmp nvidia 1080Once you've created your own bmp.blob, place it in your BSP's bootloader
directory (Linux_for_Tegra/bootloader/bmp.blob) and reflash your board
to have the blob written to flash and used by CBoot on the next boot.The size of the bmp.blob shipped with current L4T releases is 70988
bytes. Jetson boards allocate a BMP partition in flash*.xml that is
large enough for that size blob, plus some slack. Limit your blob to three
BMP files at most, and use compression so that it will fit on all boards.
You can flash it with a full reflash, or by specifying the BMP partition
as the only one to reflash on the command line as below:sudo ./flash.sh -r -k BMP  Note that BMP splash happens late in boot, just before the kernel is
loaded and executed.

3.存放bmp.blob

将新的bmp.blob改成新的名称放入bootloader文件夹或直接替换文件夹内的bmp.blob文件。已经刷过机的话，更换logo只单独刷新BMP分区即可， 执行下行指令刷入新的开机logo： 

laji@laji-Inspiron-560s:~/TX2-NX/Linux_for_Tegra/tools/bmp-splash$ mv config_file.example config_file
laji@laji-Inspiron-560s:~/TX2-NX/Linux_for_Tegra/tools/bmp-splash$ vi config_file
laji@laji-Inspiron-560s:~/TX2-NX/Linux_for_Tegra/tools/bmp-splash$ mv 1.bmp my1080.bmp
laji@laji-Inspiron-560s:~/TX2-NX/Linux_for_Tegra/tools/bmp-splash$ OUT=$PWD ./genbmpblob_L4T.sh t210 ./config_file ./BMP_generator_L4T.py /usr/bin/lz4c bmp.blob
BMP IMAGE INFO   : ./my1080.bmp nvidia 1080
记录了1+0 的读入
记录了1+0 的写出
1 byte copied, 0.000344971 s, 2.9 kB/s
记录了1+0 的读入
记录了1+0 的写出
1 byte copied, 0.000321287 s, 3.1 kB/s
记录了1+0 的读入
记录了1+0 的写出
1 byte copied, 0.000329968 s, 3.0 kB/s
记录了1+0 的读入
记录了1+0 的写出
1 byte copied, 0.000299528 s, 3.3 kB/s
mv: 'bmp.blob' 与'bmp.blob' 为同一文件
laji@laji-Inspiron-560s:~/TX2-NX/Linux_for_Tegra/tools/bmp-splash$ ls
bmp  bmp.blob  bmp-blob-README.txt  BMP_generator_L4T.py  config_file  genbmpblob_L4T.sh  my1080.bmp
laji@laji-Inspiron-560s:~/TX2-NX/Linux_for_Tegra/tools/bmp-splash$ cp bmp.blob ../../bootloader/
Display all 157 possibilities? (y or n)
laji@laji-Inspiron-560s:~/TX2-NX/Linux_for_Tegra/tools/bmp-splash$ cp bmp.blob ../../bootloader/b
badpage.bin    bmp.blob       boot.img       boot.img.sb    bpmp.bin       bpmp_t194.bin
laji@laji-Inspiron-560s:~/TX2-NX/Linux_for_Tegra/tools/bmp-splash$ cp bmp.blob ../../bootloader/bmp.blob
laji@laji-Inspiron-560s:~/TX2-NX/Linux_for_Tegra/tools/bmp-splash$ mv bmp.blob ../../bootloader/bmp.blob

sudo ./flash.sh   -r -k   BMP  --image /bootloader/bmp.blob       

 对于agx-xavier, board 就是jetson-xavier，target-flash为mmcblk0p1；

对于第三方厂家的载板， board 就是厂家载板名字例如rtso-6002，target-flash为mmcblk0p1；

sudo ./flash.sh -r -k BMP --image bootloader/bmp.blob rtso-6002-tx2-nx mmcblk0p1

4.烧写完成 

这个时候仅仅是改变了内核加载前的logo， 账户登录时还有login logo，图片位于jetson设备目录 /usr/share/background中。

5.修改登录界面logo 

• 准备一个背景壁纸
• 复制图片到/usr/share/backgrounds/目录下
• sudo cp 背景壁纸 /usr/share/backgrounds/
• 编辑配置文件/etc/alternatives/gdm3.css

• # 默认
  #lockDialogGroup {                                                               background: #2c001e url(resource:///org/gnome/shell/theme/noise-texture.png); background-repeat: repeat; }//替换为
  #lockDialogGroup {background: #2c001e url(file:///usr/share/backgrounds/背景壁纸);         background-repeat: no-repeat;background-size: cover;background-position: center; }

• 重启

6.修改启动页面logo

 sudo cp 微信图片_20230209094942.png /usr/share/backgrounds/

sudo mv 微信图片_20230209094942.png NVIDIA_Login_Logo.png

 7.修改背景logo

 鼠标右击选择change backgrounds ,即可更换

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