昇龍 (Shēnglóng; ShengLoong)

昇龍 upgrades your LoongArch system with outdated glibc symbol version in-place, to GLIBC_2.36, and checks your system for other obsolete ABI features so your system stays on the bleeding-edge upstreamed ABI without having to get reinstalled from time to time. For everyone else this is pretty much useless, and the project is bound to be obsoleted in a year or two, after the LoongArch ABI fully matures.

昇龍 (Simplified Chinese: 升龙) means "rising dragon", also literally "upgrade loong", which is exactly what this tool does.

I delibrately chose the traditional characters for the name, even though most LoongArch users are probably more used to Simplified Chinese, because the name does not sound "too literal" this way. Plus, the "rising sun" connotation seems good for such an emerging architecture.

Installation

Gentoo

昇龍 is packaged in the loongson-overlay, and should be available in the main tree shortly.

emerge app-portage/shengloong

From source

昇龍 should work on any POSIX system.

First make sure the dependencies are available. The dependencies are:

• libelf for handling ELF files, obviously
• popt for parsing CLI options
• meson as the build system
• preferably ninja as the fast Make replacement

Any version would work, but make sure you have the development headers/libs in place too if your distribution packages them separately.

# Debian and derivatives (e.g. Ubuntu)
sudo apt-get install libelf-dev libpopt-dev meson ninja-build

# Gentoo and derivatives; meson and ninja should already be present.
sudo emerge virtual/libelf dev-libs/popt

Then build like any other Meson project.

meson setup <builddir>  # replace with your preferred name for a build dir
ninja -C <builddir>

The executable should be available at <builddir>/shengloong.

Usage

昇龍 can be used to migrate LoongArch sysroots from any architecture, not just limited to native operation. As atomic replacing of files is not yet implemented, currently you have to reboot into another system for migrating your existing sysroot. (This is planned for the next minor version.)

Warning. This program has no warranty, like almost every free software.

ALWAYS BACKUP BEFORE PROCEEDING.
ALWAYS BACKUP BEFORE PROCEEDING.
ALWAYS BACKUP BEFORE PROCEEDING.

Usage: shengloong <root dirs>
  -v, --verbose                 produce more (debugging) output
  -p, --pretend                 don't actually patch the files
  -f, --from-ver=GLIBC_2.3x     migrate from this glibc symbol version
                                (default: "GLIBC_2.35")
  -t, --to-ver=STRING           deprecated; no effect now
  -a, --check-syscall-abi       scan for syscall ABI incompatibility, don't
                                patch files
  -o, --check-objabi            scan for obsolete object file ABI usage, don't
                                patch files

Help options:
  -?, --help                    Show this help message
      --usage                   Display brief usage message

Examples:

# see what needs to be done but not actually patching anything
sudo shengloong -p /path/to/sysroot

# execute the migration
sudo shengloong /path/to/sysroot

# after the migration, you may also check if you have to get rid of newfstatat
# usage in your system
sudo shengloong -a /path/sysroot

# you could also migrate multiple sysroots in one invocation
sudo shengloong /sysroot/a /sysroot/b

# for fresher installations (those after 2022-08 but before early 2023), you
# could preemptively check for lingering object file ABI v0 usage, to avoid
# having problems with newer upstream toolchain components such as lld or mold
sudo shengloong -o /path/to/sysroot

The examples are sudo-prefixed to avoid having insufficient permissions while reading certain privileged executables and/or libraries.

License

This project is licensed under GPL, version 3 or later.