[fpc-devel] More on arm4, armi and thumb

[Felipe Monteiro de Carvalho]

Hello,

It seams that building arm4 software isn't supported for Symbian OS.
At least for third-party software, and any example build for it
crashes on startup. So I was investigating other solutions.

I was reading the nokia wiki:

http://wiki.forum.nokia.com/index.php/ARM4,_ARMI_&_THUMB

http://wiki.forum.nokia.com/index.php/Build_Targets

Quoting:

"ARMI is the 32-bit instruction set with extra logic to allow it to
call THUMB code in addition to other 32-bit code. ARMI is known as ARM
interchange format."

It seams that ARMI could be a solution. Executables built for ARMI
actually work normally, but there seams to be a lack of information of
what exactly is ARMI. The descriptions found are not detailed enougth.

My greatest doubt is: Can I just compile normal arm4 object files with
fpc and link them together with armi compiled object files to get the
final executable?

I have a fealing this could work, even if FPC doesn't do that "extra
logic to call THUMB", because we don't call the OS routines directly,
but rather thougth a c wrapper.

I will, of course, just test, but it will be a lot of work, and if
someone knows in advance this should theoretically work, or shouldn't,
that could speed things up =)

thanks,
-- 
Felipe Monteiro de Carvalho