==================================
参考链接：
https://club.rt-thread.org/ask/question/2f057e8dadf6b157.html
==================================
1、问题描述：
用RT-Thread studio软件新构建一个项目，编译正常0error、0warning，但是用jlink下载固件，显示执行完毕，但是实际上是没有烧录到板子上面的情况：
如下为jlink下载时候的日志：
开始下载程序：2023-02-07 11:34:43
Download Start Address: 0x08000000
D:\RT-ThreadStudio>"D:/RT-ThreadStudio/repo/Extract/Debugger_Support_Packages/SEGGER/J-Link/v7.50a\JLink.exe" -device STM32F103C8 -ExitOnError -CommanderScript D:\RT-ThreadStudio\workspace2/.metadata/Temp/rtthread_download_init.jlink
SEGGER J-Link Commander V7.50a (Compiled Jul 8 2021 18:22:32)
DLL version V7.50a, compiled Jul 8 2021 18:21:11
J-Link Commander will now exit on Error
J-Link Command File read successfully.
Processing script file...
J-Link connection not established yet but required for command.
Connecting to J-Link via USB...O.K.
Firmware: J-Link ARM-OB STM32 compiled Aug 22 2012 19:52:04
Hardware version: V7.00
S/N: 20090929
License(s): RDI,FlashDL,FlashBP,JFlash,GDBFull
VTref=3.300V
Selecting SWD as current target interface.
Device "STM32F103C8" selected.
Selecting 1000 kHz as target interface speed
Target connection not established yet but required for command.
Device "STM32F103C8" selected.
Connecting to target via SWD
InitTarget() start
InitTarget() end
Found SW-DP with ID 0x1BA01477
Failed to power up DAP
InitTarget() start
Can not attach to CPU. Trying connect under reset.
Connecting to CPU via connect under reset failed.
InitTarget() end
InitTarget() start
Can not attach to CPU. Trying connect under reset.
Connecting to CPU via connect under reset failed.
InitTarget() end
InitTarget() start
Can not attach to CPU. Trying connect under reset.
Connecting to CPU via connect under reset failed.
InitTarget() end
Cannot connect to target.
Script processing completed.
执行完毕, 耗时：17091ms.
2、问题解决：
网上有类似的情况，使用j-flash擦除，然后重新下载就可以了，我好像是重新断电重启之后，jlink就可以正常下载了，后续要是出问题再用j-flash擦除试试；
如下正常jlink下载会弹出这个窗口：
总结：思路就是先排查
- 硬件连接是否正确，重启试下
- 项目工程用RT-Thread studio创建是否正确选择了jlink模式，刚创建的工程可以重新创建下
- 然后是就是jlink下载问题，用j-flash擦除下重新下载