topic What's this command mean? in Other NXP Products

What's this command mean?

CaoJason — Tue, 09 Sep 2008 18:29:43 GMT

Hello:

Who can give me the detail explain about" FORCEACTIVE { gInterruptVectorTable, __reset, __ext_int, __decr, __machine_check }"

This command is in the link file MPC564EVB_ROM.lcf.

thanks!

Re: What's this command mean?

CrasyCat — Tue, 09 Sep 2008 19:28:14 GMT

Hello

This commands disable dead stripping for the symbols gInterruptVectorTable, __reset, __ext_int, __decr, __machine_check.

That means that the symbols enumerated above will be linked to the application even though they are not referenced in there.

CrasyCat

Re: What's this command mean?

CaoJason — Wed, 10 Sep 2008 13:56:59 GMT

Hi Cat:

In the file,the __reset, __ext_int, __decr, __machine_check are the function dealing exception,That means function cann't be used to deal some application if it is not listed in FORCEACTIVE{}

Another question: .equ vec_base 0x3FE000,what does this sentence mean?

Re: What's this command mean?

CrasyCat — Wed, 10 Sep 2008 18:19:56 GMT

Hello

The problem with interrupt function is that they are not explicitly called in the application. So if you do not specify them in a FORCEACTIVE command they may not be linked with the application.

Usually one would create a constant table of function pointer for the interrupt table and then specify the table in the FORCEACTIVE command. This would make sure that all interrupt functions, which address is specified in the table gets linked to the application.

The statement .equ vec_base 0x3FE000 is probably stored somewhere in an assembly source file.

It associates the value 0x3FE000.to symbol vec_base.

So each time you will use vec_base in your assembly source file, assembler will replace that with 0x3FE000.

CrasyCat

Re: What's this command mean?

CaoJason — Wed, 10 Sep 2008 19:22:39 GMT

Thanks Cat,I get it.