Hello On Wed, Oct 17, 2018 at 12:37 PM Dutch Ingraham <stoa@xxxxxx> 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 Here is what I ran to make your example working on my Arch Linux machine sudo pacman -S lib32-glibc as --32 -o asm.o asm.s ld -melf_i386 --dynamic-linker /lib/ld-linux.so.2 -L/usr/lib32 -lc -o asm asm.o ./asm The only difference that I specified -L (library search path) to make sure the linked can find 32-bit version of libc.
