PB compilation error: blddemo there were errors building k390

The following error occurs during Pb Compilation:
Blddemo: there were errors building k390
I: I checked it on Google. It is recommended to delete all files except project files *. pbxml in the project directory, restart the computer, and then sysgen.
The attempt is still wrong.
2. view the D:/wince500/build. Err file with the following information:
D:/wince500/build. Log (1): Error sysgen0000: Error (s) in sysgen phase
Google again. We recommend that you check build. log.
3. Open build. log with the following information:
Directory: D:/wince500/public/common/cesysgen
Targetname: pxa255_serial
Makefile. Def: including D:/wince500/public/common/oak/MISC/sources. releasetype_oak
Nmake: Fatal error u1073: Don't Know How To Make 'd:/wince500/pbworkspaces/k390/wince500/smdk2440a_armv4i/cesysgen/oak/lib/armv4i/retail/shares'
Stop.
Nmake: Fatal error u1077: 'd:/wince500/SDK/bin/i386/nmake.exe ': return code '0x2'
Stop.
It turns out that I used PXA255 in source insightCodeDirectly to delete. Because I have never used PXA255.
Find the CSP folder under D:/wince500/public/common/oak, and find a lot of useless things in the CSP folder,
By default, WinCE will compile these things. If you delete the content, the compilation will fail!
Restore the folder and run sysgen again to solve the problem.