I watched the syscalls with strace and my assumption was confirmed. function Fpmmap( start: pointer; len: size_t; prot: cint; flags: cint; fd:cint; offst: off_t ):pointer;
My offst value for fpmmap is $100000000. strace output: mmap(NULL, 1920000, PROT_READ|PROT_WRITE, MAP_SHARED|MAP_32BIT, 3, 0) = -1 EINVAL Here the value is 0. It is likely that the offst value is stripped to 32 bit before passed to the mmap syscall. Am Samstag, 21. November 2020, 01:15:20 CET schrieb Alexander Grotewohl via fpc-pascal: > It would seem C handles this at compile time with a define.. mapping mmap to > mmap64. Which would almost seem to imply you'd end up with a 32 bit binary > that would only work on 64 bit systems. I'm not really sure how this would > work for Pascal. You could start by looking in the file listed in the > fpmmap docs you posted. My guess is the easiest answer is "distribute both > 32 and 64 bit versions," but that doesn't help when you need to test the 32 > bit one.. > > -- > Alexander Grotewohl > https://dcclost.com > > -- > Alexander Grotewohl > https://dcclost.com > ________________________________ > From: fpc-pascal <fpc-pascal-boun...@lists.freepascal.org> on behalf of > Rainer Stratmann via fpc-pascal <fpc-pascal@lists.freepascal.org> Sent: > Friday, November 20, 2020 6:33:51 PM > To: fpc-pascal@lists.freepascal.org <fpc-pascal@lists.freepascal.org> > Cc: Rainer Stratmann <rainerstratm...@t-online.de> > Subject: [fpc-pascal] fpmmap problem 64 bit linux > > A 32 bit freepascal program on a 32 bit Linux Debian system is working > properly. It uses fpmmap for getting the adress of a kms framebuffer. > > The same 32 bit program on a 64 bit Linux Debian system *** is not working. > When it comes to the fpmmap it gives an error: > > Sys_EINVAL > One of the record fields Start, length or offset is invalid. > > https://www.freepascal.org/docs-html/rtl/baseunix/fpmmap.html > > I figured out that it likely can only be the offset value since start and > length are always the same. > > The offset value I got from a previous DRM function. > > On the 32 bit System this offset value is $10000000 (fits in 32 bit) > And on the 64 bit System this offset value is $100000000 (does not fit in 32 > bit). > > Can it be possible that the fpmmap function strips the offset value to 32 > bit? Is there another way to call fpmmap more directly? > What does fpmmap exactly? > Where can I research? > > > *** > dpkg --add-architecture i386 > apt-get update > apt-get install libc6-i386 > > > _______________________________________________ > fpc-pascal maillist - fpc-pascal@lists.freepascal.org > https://lists.freepascal.org/cgi-bin/mailman/listinfo/fpc-pascal _______________________________________________ fpc-pascal maillist - fpc-pascal@lists.freepascal.org https://lists.freepascal.org/cgi-bin/mailman/listinfo/fpc-pascal
