On Wed, Oct 17, 2018 at 9:37 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: . Assembly succeeds.

However, when linking using the command

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:

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

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

Silly question perhaps but does that file actually exist, /lib32/ld-linux.so.2? I haven't set up 32 bit etc and that file doesn't exist on my machine, and I get the exact same errors as you.

On Wed, Oct 17, 2018 at 10:59:07PM +0200, Andy Pieters wrote:

On Wed, Oct 17, 2018 at 9:37 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: . Assembly succeeds.

However, when linking using the command

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:

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

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

Silly question perhaps but does that file actually exist, /lib32/ld-linux.so.2?

I haven't set up 32 bit etc and that file doesn't exist on my machine, and I get the exact same errors as you.

No, but /usr/lib32/ld-linux.so.2 does, as a symlink to ld-2.28.so. As noted, I've tried that as well, with the same results.

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 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: . Assembly succeeds.

However, when linking using the command

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:

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

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

On Wed, Oct 17, 2018 at 08:14:48PM -0700, Anatol Pomozov via arch-general wrote:

Hello On Wed, Oct 17, 2018 at 12:37 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: . Assembly succeeds.

However, when linking using the command

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:

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

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.

Hi Anatol: I was able assemble and link with gcc, then look at the library paths used with ldd. Actually, your command is the same as the command above, minus the 'shared' option, from the Forum post. That command was core dumping for me; not sure how it was working for them. Thanks for your help; your command works fine.