as(1) on Solnix vs Linux and the BSDs

On Solnix, as is the GNU assembler from pkgs.solnix.binutils, and it is not in the base system. The Solnix and Linux pages have the same SYNOPSIS and the same described behaviour. Only a few configure-dependent options differ.

What Solnix runs

Not installed by default: add pkgs.solnix.binutils. The bundle lists no other illumos variants and includes no illumos as text, so it does not say what, if anything, is at /usr/bin/as on a default system.

Differences

Compared withTopicWhat differs
Linuxsame programSolnix as is the GNU assembler, the same program family as the Linux binutils as. The SYNOPSIS, the DESCRIPTION and the listing options (-a[cdghilmns][=file]) are identical in the two pages.
Source: Solnix as(1) SYNOPSIS, DESCRIPTION; Linux as(1) SYNOPSIS, DESCRIPTION
Linuxnot in the base systemOn Linux the page documents the installed binutils as. On Solnix the command is absent until you install pkgs.solnix.binutils, so a build script that calls as fails with command-not-found on a fresh system.
Source: Solnix bundle header (on PATH: none: install pkgs.solnix.binutils)
Linuxx86 TLS check optionThe extracted flags show --enable-x86-tls-check only on the Linux page. The Solnix page's extracted flags do not list it.
Source: Linux as(1) option flags (--enable-x86-tls-check); Solnix as(1) option flags
LinuxRISC-V privileged spec optionThe extracted flags show --with-priv-spec only on the Linux page. The Solnix page lists --with-isa-spec and --with-arch instead. The text of these entries is trimmed, so the bundle does not show what they do.
Source: Linux as(1) option flags (--with-priv-spec); Solnix as(1) option flags (--with-arch, --with-isa-spec)
Linuxconfigure-time optionsThe Solnix flag list includes --enable-64-bit-bfd, --enable-elf-stt-common and --enable-generate-build-notes, which are configure options. The Linux flag list has only --enable-x86-tls-check as a configure option. The text is trimmed, so the bundle does not show how they differ.
Source: Solnix as(1) option flags; Linux as(1) option flags
Linuxdebug section compression defaultBoth pages say --nocompress-debug-sections is usually the default except on x86/x86_64, and that a configure-time option can override this. The default therefore depends on how each binutils build was configured, and the Solnix page does not say how its build was configured.
Source: Solnix as(1) --nocompress-debug-sections; Linux as(1) --nocompress-debug-sections
FreeBSD, OpenBSD, NetBSDno BSD counterpart in the bundleThe bundle has no as(1) page for FreeBSD, OpenBSD or NetBSD. The manual cannot support any claim about how their assemblers differ from the Solnix GNU as.
Source: Bundle header (only a linux counterpart listed)

Standards

  • POSIX: as is not a POSIX.1-2024 utility.

Writing portable scripts

  • Do not assume as is present on a fresh Solnix system. Install pkgs.solnix.binutils, or check for it before using it in a build script.
  • Use only the options common to the pages, such as -o, --defsym, -I and -a listings. Check the --version output of the as in use before relying on configure-dependent options.

Every difference here is taken from the manual pages linked above: Solnix's published page, Linux (man-pages and the GNU and util-linux manuals), FreeBSD, OpenBSD and NetBSD. Each row names its source. Where a manual is silent, this page is too. Compiled 2026-10-26. Found a mistake? Mail hackers@lists.solnix.io.