Issues in real DOS on a 486

DOS specific questions.
rugxulo
Posts: 219
Joined: Jun 30, 2006 5:31
Location: Usono (aka, USA)
Contact:

Re: Issues in real DOS on a 486

Post by rugxulo »

marcov wrote:And if you use modern (read: 32-bit) tools, always disable the option to discard unused code (--gc-sections and friends on GCC, -XX "smartlinking" on FPC). Dead code optimization requires a disproportionate amount of memory.
DJGPP's COFF doesn't support that, nor does PE/COFF (last I checked). GCC's online manual (3.10 Options That Control Optimization) only says it's supported by "most ELF systems, SPARC/Solaris 2, and maybe AIX in the future".
marcov
Posts: 3455
Joined: Jun 16, 2005 9:45
Location: Netherlands
Contact:

Re: Issues in real DOS on a 486

Post by marcov »

Yeah, that is why we have internal assemblers+ linkers. GCC+binutils sux on non-unix. GDB too, but we haven't found away around that yet :-)

Seriously, there is always poor man's version, not on linker level, but by wrapping each symbol in a separate .o file (which gets its own section by default). Either as used by (very) old versions of FPC, or by doing some creative assembler transformations.

I've seen LD use 1.5+ GB using that method though, to generate a 6MB .EXE.
DOS386
Posts: 798
Joined: Jul 02, 2005 20:55

Re: Issues in real DOS on a 486

Post by DOS386 »

Secondly, I found out that FreeBASIC doesn’t work unless you have a FPU
This had been already discussed: http://www.freebasic.net/forum/viewtopi ... 81#p113881

I still think that some sort of "no-init-fpu" switch should be available (and maybe also "no-catch-exceptions" and "no-ntvdm-hacks").
Post Reply