Date: Mon, 30 Aug 2010 19:40:01 +0400 From: pluknet <pluknet@gmail.com> To: Tijl Coosemans <tijl@coosemans.org> Cc: freebsd-arch@freebsd.org Subject: Re: Support for cc -m32 Message-ID: <AANLkTi=%2BuG4qEpavQVtrAaCuu1SLQ9--kJGmv9LYCvEm@mail.gmail.com> In-Reply-To: <201008301731.19074.tijl@coosemans.org> References: <201007291718.12687.tijl@coosemans.org> <201008301731.19074.tijl@coosemans.org>
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On 30 August 2010 19:31, Tijl Coosemans <tijl@coosemans.org> wrote: > On Thursday 29 July 2010 17:18:03 Tijl Coosemans wrote: >> I've put the initial version of some patches online to support cross >> compilation of 32 bit binaries on amd64. It's modelled after how NetBSD >> does this. >> >> With these patches something like "cc -m32 -o test test.c -pthread -lm" >> generates a program that runs on FreeBSD/i386. >> >> http://people.freebsd.org/~tijl/cc-m32-1.diff >> http://people.freebsd.org/~tijl/cc-m32-2.diff >> http://people.freebsd.org/~tijl/cc-m32-3.diff >> >> *cc-m32-1.diff* : Let ld and cc find 32 bit libraries. >> >> *cc-m32-2.diff* : Install i386 headers on amd64. >> >> With this patch headers for a particular $arch are always installed >> under /usr/include/$arch and /usr/include/machine becomes a symlink. >> >> A question I have here is how best to clean up the old machine >> directory. The patch currently uses 'rm -rf'. >> >> Another problem I encountered was that during the build of >> usr.bin/kdump all headers are searched for definitions of ioctl >> requests and a C source code file is generated that includes all those >> headers. This fails when both i386 and amd64 headers are installed >> because they can't both be included at the same time. For now the patch >> simply blacklists /usr/include/i386, but actually all $arch should be >> excluded. The ioctl requests can still be found through the machine >> symlink. If someone has a better idea... >> >> *cc-m32-3.diff* : Modify amd64 headers to include i386 headers when >> =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 __i386__ is defined. >> >> This patch modifies the amd64 headers to follow this format: >> >> =A0 #ifndef _AMD64_HEADER_H >> =A0 #define _AMD64_HEADER_H >> >> =A0 #ifdef __i386__ >> =A0 #include <i386/header.h> >> =A0 #else >> >> =A0 ... >> >> =A0 #endif /* __i386__ */ >> =A0 #endif /* !_AMD64_HEADER_H */ >> >> This way including <machine/header.h> works for -m32. There are a few >> i386 headers which don't exist for amd64: >> >> apm_segments.h >> bootinfo.h >> cserial.h >> elan_mmcr.h >> if_wl_wavelan.h >> ioctl_bt848.h >> ioctl_meteor.h >> npx.h >> pcaudioio.h >> pcb_ext.h >> perfmon.h >> privatespace.h >> smapi.h >> speaker.h >> vm86.h >> xbox.h >> >> Theoretically a dummy amd64 header should be created for each of them >> that just includes the i386 header. The patch does this for npx.h. The >> other headers seem to be really i386 specific or even outdated. If it >> were ever necessary to cross-compile code that uses them, it would be >> easy to modify that code to directly include <i386/header.h>. >> >> >> Feel free to test the patches and to comment on any part of them. > > I'd like to move forward with this now. I've rebased the patches above > against today's CURRENT. If there are no further objections I'd like to > commit them a few days from now, let's say Saturday. > Hi. The trouble I faced while was playing with my -m32 work was a cross buildworld error on amd64 with TARGET set to i386. Have you checked there is no such an issue? --=20 wbr, pluknet
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