On Wed, Oct 17, 2018 at 11:07:02PM +0200, Maarten de Vries via arch-general wrote: > Why not let gcc take care of what compiler/assembler and linker to invoke > with which precise flags: > > $ gcc -m32 -o foo filename.s > $ ./foo # great success! > > It will probably link to libc without you even asking for it. And if that > works and you really want to know what linker flags you need, you can add -v > to make gcc spam you about it. > GCC will handle some files, but not others. In this case, I get garbage output then a segfault/core dump. Using -nostdlib and -static also fail to build, but I have had success with just using <gcc -m32 -nostartfiles -o file file.s> I would, however, like to know how to use as/ld on Arch, as it is my main OS. > > -- Maarten > > (Sent off-list by accident before, sending to the list now.) > > > On 10/17/18 9:36 PM, Dutch Ingraham wrote: > > Hi all: > > > > I'm having a problem linking 32-bit GAS assembly code that references external > > C libraries on an up-to-date 64-bit Arch installation. > > > > I have enabled the 32-bit repositories and installed the multilib-devel group > > and lib32-glibc. I have updated the library cache with ldconfig and rebooted. > > > > The command to assemble is: <as --32 -o filename.o filename.s>. Assembly > > succeeds. > > > > However, when linking using the command > > <ld -melf_i386 --dynamic-linker /lib32/ld-linux.so.2 -lc -o filename filename.o> > > > > the command fails with: > > ld: skipping incompatible /usr/lib/libc.so when searching for -lc > > ld: skipping incompatible /usr/lib/libc.a when searching for -lc > > ld: cannot find -lc > > > > Note this linker command (or a hierarchy-appropriate one) seems standard, and > > succeeds on a 64-bit Debian OS. > > > > There is a fairly recent Forum question (but pre-dating the discontinuance of > > i686 support) regarding the same issue at > > https://bbs.archlinux.org/viewtopic.php?id=229235 which indicates the command > > should be: > > > > <ld -melf_i386 -shared -L /usr/lib32 -dynamic-linker /lib/ld-linux.so.2 -o \ > > filename filename.o -lc> > > > > This command succeeds, insofar as the linker returns an exit code of 0. However, > > running the program (and all other similar programs) fails with "Illegal > > instruction (core dumped)." Assembling with debugging symbols and running a > > backtrace didn't enlighten me. > > > > Note that changing /lib/ld-linux to /usr/lib32/ld-linux in the command immediately > > above produces the same result, as confirmed by the output of <ldconfig -p> > > > > Anyone see something I've missed of have any suggestions? Thanks. > > > > > > ----------- > > > > Here is some simple code to test with: > > > > > > # paramtest2.s - Listing system environment variables > > .section .data > > output: > > .asciz "%s\n" > > .section .text > > .globl _start > > _start: > > movl %esp, %ebp > > addl $12, %ebp > > loop1: > > cmpl $0, (%ebp) > > je endit > > pushl (%ebp) > > pushl $output > > call printf > > addl $12, %esp > > addl $4, %ebp > > loop loop1 > > endit: > > pushl $0 > > call exit
