Lionel Debroux (./3) :
That explains... Do you by chance remember what change broke an older kernel.h ? Or, do you have some factual information (release, SCM) about when this happened approximately, which would help finding out what broke kernel.h ?

I don't remember.
Probably 0.94 -> 0.95

Lionel Debroux (./3) :
Most changes of kernel.h wrt TIGCC include files seem to be located in compat.h and kbd.h. For the vast majority of headers #include'd by tigcclib.h, surrounding the "#include " by #ifndef __KERNEL_H__ / #endif in the non-auto-generated part of most TIGCC header most files should cut most of the copy&paste while not interfering with the kernel.h definitions - and in the process, reducing the risks of missing several definitions and not keeping up with updates.

Yes.
All the changes are in compat.h
All other files are copy and paste of the header files
I don't think I have modified kbd.h. What changes were done?

Lionel Debroux (./3) :
BTW, bug report: I noticed kernel.h of PreOS 1.0.5 lacks __Folder_Del: #define __Folder_Del _rom_call(short,(const char*,short),66)