ISO/IEC 23360-7-2:2021

Overview

ISO/IEC 23360-7-2:2021 - Linux Standard Base (LSB) Part 7-2 defines the LSB Core specification for the S390 architecture. It supplements the LSB Core - Generic (common part) with S390-specific binary and runtime interfaces so that compiled applications behave predictably on IBM Z / s390 systems. The document is primarily an Application Binary Interface (ABI) specification (with related APIs), describing executable formats, dynamic linking, required libraries, and a minimal installation environment to support high-volume, portable applications.

Key Topics and Requirements

• ABI / API scope: Defines the system interface for compiled applications and a minimal environment for installation scripts. The LSB contains both APIs (source-level) and ABIs (binary-level); this part is S390-specific.
• Executable and Linking Format (ELF): Sections on ELF header, sections, symbol tables, relocations, and debug information tailored to S390.
• Machine and calling conventions: Machine interface, function calling sequence, process initialization and operating-system interface specifics for S390.
• Program loading & dynamic linking: Requirements for program interpreters/dynamic linkers and behavior of dynamic linking on S390.
• Mandatory base libraries: Lists of required ABIs and symbols in libraries such as libc, libm, libpthread, libdl, libgcc_s, libcrypt and utility libraries (e.g., libz, ncurses).
• Package & installation considerations: Guidance on package dependencies and architecture considerations for software installation and deployment.
• Conformance rules: Implementations must provide all ABIs listed here (except where explicitly optional). The specification encourages techniques such as symbol versioning to preserve backward compatibility.

Applications and Who Uses It

• Linux distributors and OS vendors implementing S390 systems to ensure binary compatibility with LSB-conformant packages.
• Compiler and toolchain developers who must emit correct ABI-compliant binaries for S390.
• Independent software vendors and packagers producing high-volume commercial or enterprise applications targeting IBM Z hardware.
• Middleware and library maintainers ensuring required symbols and interfaces are available and correctly versioned.
• Certification and QA teams verifying that systems meet LSB Core requirements for portability and predictable runtime behavior.

Related Standards

• Use in conjunction with LSB Core - Generic (the common part) and other LSB modules referenced by this part.
• Relies on broader standards and formats such as ELF and conventions described in the LSB family; consult ISO/IEC 23360 series listings for related parts.

Keywords: ISO/IEC 23360-7-2:2021, Linux Standard Base, LSB, S390 architecture, ABI, API, ELF, dynamic linking, libc, libpthread, symbol versioning, package installation.