On Thu, 19 Aug 2004, Luchezar Georgiev wrote: > Hallo Bart, > > > Question is how much of a difference can you tolerate? From you I get > > the impression that a 100K uncompressed kernel that compresses to 39999 > > bytes would be preferable to a 64K one that compresses to 40000 bytes. > > ;-) I could never use an uncompressed kernel that is below 64 KB. > OpenWatcom makes the FAT32/80386 unstable kernel 66330 bytes long. The > maximum size that UPX accepts is 65350 bytes. The difference is almost a > kilobyte. How could we reduce the kernel further without crippling it? > It's difficult!
Well if I claim I can get it under 64K I'm not lying. OW compiles *plain 2035* as 66318 bytes uncompressed for me for FAT32/386. Why your kernel is bigger after all these optimizations is a puzzle. I've read that on low memory machines its optimizer may be limited but I can't think of anything else. For the unstable branch it's 64700 or so. Changing the calling convention to #pragma aux default parm [ax dx cx] modify [ax dx es fs] in portab.h (careful, don't do that for SYS & EXEFLAT) and making LoL (init-mod.h, main.c) extern struct lol FAR * const LoL; (see the const) chops of another couple 100s of bytes. > > I've seen compressed differences between Turbo C++ 1.01 and OW going > > down over the years. As for Borland, is it worth spending $59+postage > > for an unsupported product on an obscure Ebay site when so many free > > compilers are available? > > It's not worth a penny because it can be freely downloaded from Vietnam (I > posted the URL here ;-) The smiley implies that it can't be freely downloaded from Vietnam. Maybe you can but I can't. Everything can be physically downloaded. But that's a silly argument and by publically encouraging it you're not doing this project a favour. > > How about Digital Mars for instance? > > A very good compiler in my opinion, backed by Walter Bright's C++ great > compiler "know-how", but Tom once wrote that he gave up porting the kernel > to it as he didn't see advantages. Sure, Tom's primary interest wasn't compressed kernel sizes at the time, just the uncompressed time (IIRC this was before compressing was even on the radar screen). > Does that < 64K kernel support FAT32? Of course. > Besides, aPack doesn't compress .SYS files at all. An incorrect comparison again. Right, checking again I see it compresses a SYS file like a COM file. Well with some hand holding (load at 50:100) you could treat kernel.sys like a COM file too. Haven't tried that though. Bart ------------------------------------------------------- SF.Net email is sponsored by Shop4tech.com-Lowest price on Blank Media 100pk Sonic DVD-R 4x for only $29 -100pk Sonic DVD+R for only $33 Save 50% off Retail on Ink & Toner - Free Shipping and Free Gift. http://www.shop4tech.com/z/Inkjet_Cartridges/9_108_r285 _______________________________________________ Freedos-kernel mailing list [EMAIL PROTECTED] https://lists.sourceforge.net/lists/listinfo/freedos-kernel
