FPC 2.6.4irc

A preservation fork of Free Pascal Compiler 2.6.4 for BBS and retro software. Release r3 (2026-07-12), patched r3.1 (2026-07-14). Codepage-aware AnsiStrings, DOS TCP/IP sockets (Watt-32), COFF object writer fix, cross-build from Linux with bundled tools, OS/2 cross-compilation (import linking solved plus the first-ever OS/2 TProcess for fcl-process). Ships the FPC text-mode IDE and Lazarus 1.2.6 LCL, each self-contained. Proven end-to-end: Mystic BBS v1.10 A38irc compiles 56/56 across native Linux, Windows, DOS, and OS/2. 169 string/socket assertions + 75 tool/platform checks; binary-protocol safe.

See MILESTONE-R3.md for the full r3 summary.

What's new over stock FPC 2.6.4

r3.1 patches (2026-07-14)

• Native ld linker fix: link.res (a full replacement linker script) is now passed with -T, fixing hangs and "Can't call the linker" errors on modern binutils (2.19+, e.g. 2.42 on current Ubuntu). Backported from FPC 3.2.2's approach.
• Prebuilt FPC packages for all six targets: fcl-net (netdb), hash (md5, sha1, crc), paszlib (7 units), fcl-process (pipes, process). Consumers no longer need extra -Fu paths for these packages.
• Mystic socket layer: pure-Pascal resolver — the Unix branch of m_io_sockets.pas now uses FPC's netdb instead of the external cNetDB libc glue. No libc dependency for name resolution on Unix. Non-Unix paths (Winsock2/WinSock/Watt-32) unchanged.
• cNetDB retired to attic/retired-units/ (not deleted; restore instructions in docs/removed/cnetdb-retired.md).
• Test harness (run-tests.sh): cross-target socket tests now fall back to compile-only verification when the target cross-linker isn't installed; OS/2 section fixed to use bundled emx tools. Result: 9/9 passed, 169 assertions, ALL AVAILABLE TESTS PASSED.
• Register allocator backports from FPC 3.0: is_subh spill offset correction + LEA→ADD spill conversion in x86/rgx86.pas.

Codepage-aware strings (Phase 1 — complete)

• type AnsiString(CP_UTF8) syntax — parser backported from FPC 3.0
• Automatic codepage conversion on assignment
• UnicodeString full support (8/8 tests pass)
• widestringmanager codepage parameters
• TAnsiRec with CodePage + ElementSize fields
• TSystemCodePage, CP_UTF8, CP_ACP, CP_NONE, RawByteString
• StringCodePage(), StringElementSize(), StringRefCount(), SetCodePage()
• 47-check binary protocol safety test — telnet/BinkP/Zmodem/ANSI wire data survives all string operations without corruption

DOS networking

• Uses Sockets works on go32v2 — backed by Watt-32/libwatt.a
• Full fp* BSD API + select + FD_SET + DNS resolver + ioctlSocket
• {$linklib watt} auto-links libwatt.a
• Mystic BBS compiles with plain Uses Sockets on all 6 platforms

COFF object writer fix

• Fixed COFF section symbol storage class: C_STAT (3) not C_SECTION (104)
• Stock DJGPP binutils (2.35+) work without -Aas workaround

Cross-compilation

• -Ao flag — pass extra options to assembler
• $EXTRAOPT in all assembler command templates
• Error 127 fix: Makefile guard clears BINUTILSPREFIX for native/multilib builds (Fix A + Fix B — documented, no shim)

OS/2 fixes (linking SOLVED)

• Import-by-name uses MangledName + Cprefix (backported from 3.0.4)
• 7 cherry-picks: FileNameCasePreserving, MaxPathLen 260, error 206/290 mappings, exception parameters fix, FileOpen label fix, FSApi64
• 60 OS/2 RTL units compile (crt, sockets, so32dll added in r3)
• Linking solved: 7-part binutils patch resolves N_IMP1/N_IMP2 import symbols (patches/os2-cross/binutils-2.30-emx-nimp.patch); -Ttext 0x10000 in the ld command sets the emxbind-required entry point
• Produces a.out with zero undefined references (all DLL imports resolve)
• emxbind ported to Linux (builds and validates the a.out); final bind needs emxl.exe from the EMX runtime
• See docs/os2_linking_solved.md

go32v2 cherry-picks (Phase 2)

• StackLength -256 (prt0 safety margin)
• FileNameCasePreserving variable
• dpmiexcp.pp typo fix

Standalone DOS executables

• -WS flag embeds CWSDSTUB into go32v2 EXE at link time
• CWSDSTUB.EXE bundled in lib/cwsdpmi/

Bundled build tools (3-tier fallback)

• as, ld, ar, make bundled for all 6 platforms
• System tools preferred → bundled binary fallback → source build guidance
• Source included: binutils-2.42, binutils-2.30 (EMX), make-4.3
• Zero symlinks (Windows-safe)

Repository layout

fpc264irc/
├── src/                          # Full FPC 2.6.4 source (14,994 files)
│   ├── compiler/                 # Modified: globtype, symdef, psystem,
│   │                             #   pdecl, ptype, ncnv, ogcoff, options,
│   │                             #   globals, assemble, aggas, agx86att,
│   │                             #   asmutils, t_os2, i_go32v2
│   ├── rtl/                      # Modified: systemh, system, astrings,
│   │                             #   go32v2/sockets.pp (NEW),
│   │                             #   go32v2/system.pp, go32v2/dpmiexcp.pp,
│   │                             #   os2/system.pas, os2/sysos.inc,
│   │                             #   emx/system.pas, emx/sysutils.pp
│   └── ...                       # packages, ide, utils (stock)
├── bin/
│   ├── ppc386                    # i386 compiler
│   ├── ppcx64                    # x86_64 compiler
│   ├── units/                    # Compiled RTL per target
│   │   ├── x86_64-linux/         #   62 units
│   │   ├── i386-linux/
│   │   ├── i386-go32v2/
│   │   ├── i386-win32/
│   │   ├── i386-freebsd/
│   │   └── i386-os2/             #   60 units (linking WORKS, TProcess added)
│   └── tools/                    # Bundled cross-tools (zero symlinks)
│       ├── make                  #   GNU Make 4.3
│       ├── x86_64-linux/         #   binutils 2.42
│       ├── i386-linux/           #   binutils 2.42 (multilib)
│       ├── i386-go32v2/          #   DJGPP binutils 2.35
│       ├── i386-win32/           #   MinGW binutils 2.41
│       ├── i386-freebsd/         #   FreeBSD binutils 2.42
│       └── i386-emx/             #   Patched binutils 2.30 (a.out)
├── lib/
│   ├── watt32/                   # Watt-32 TCP/IP source
│   ├── cwsdpmi/                  # CWSDPMI r7 binaries + source
│   └── build-tools/              # Source: binutils-2.42, 2.30, make-4.3
├── test/                         # 11 test programs + 5 test scripts
│   ├── test_string_baseline.pas  #   65 checks
│   ├── test_string_codepage.pas  #   34 checks
│   ├── test_binary_protocol_safety.pas  # 47 checks
│   ├── test_auto_convert.pas     #   12 checks
│   ├── test_unicode_basic.pas    #   8 checks
│   ├── test_*_sockets.pas        #   6 platform socket tests
│   ├── run-tests.sh              #   Per-target test runner
│   ├── test-tools.sh             #   31 tool checks
│   ├── test-tool-fallback.sh     #   44 fallback checks
│   ├── test-all-platforms.sh     #   6-platform verification
│   └── test-os2-build.sh         #   OS/2 build chain test
├── patches/os2-cross/            # BFD patch + emxbind source
├── docs/
│   ├── error127_debug_log.md     # Error 127 root cause + fix
│   └── tier_fallback_system.md   # 3-tier tool fallback design
├── fpc264irc.patch               # All changes as unified diff
├── BACKPORT-METHOD.md            # 6-step cherry-pick discipline
├── MILESTONE-R2.md               # Phase plan (5 phases)
├── CHANGELOG-IRC.md
├── build-linux.sh                # 3-tier fallback build script
├── build-windows.bat
├── README.md
└── LICENSE

Quick start

bin/ppcx64 -iW                                            # 2.6.4irc
bin/ppcx64 -Fubin/units/x86_64-linux prog.pas             # Linux native
bin/ppc386 -Tgo32v2 -Fubin/units/i386-go32v2 -Fllib/watt32/lib p.pas  # DOS
bin/ppc386 -Twin32 -Fubin/units/i386-win32 p.pas           # Windows
bin/ppc386 -Tfreebsd -Fubin/units/i386-freebsd p.pas       # FreeBSD
bin/ppc386 -Tgo32v2 -WSlib/cwsdpmi/CWSDSTUB.EXE -Fubin/units/i386-go32v2 p.pas  # standalone DOS

Rebuild RTL from source

cd src/rtl
make clean OS_TARGET=linux CPU_TARGET=x86_64 FPC=../../bin/ppcx64
make all   OS_TARGET=linux CPU_TARGET=x86_64 FPC=../../bin/ppcx64 BINUTILSPREFIX=
# Units go to src/rtl/units/x86_64-linux/

Important: The trailing BINUTILSPREFIX= (empty) is required for native and i386-on-x86_64 builds. Without it, the Makefile may auto-set a prefix and fail with Error 127. This is a standard make variable override, not a workaround. If you use build-linux.sh, this is handled automatically.

Platform status

Platform	Sockets	Cross from Linux	Tools	RTL	Link
x86_64-linux	RTL native	n/a (native)	✅	✅ 84 units	✅
i386-linux	RTL native	multilib	✅	✅	✅
i386-go32v2 (DOS)	Watt-32	DJGPP binutils	✅	✅	✅
i386-win32	RTL native	MinGW binutils	✅	✅	✅
i386-freebsd	RTL native	FreeBSD binutils	✅	✅	✅
i386-emx (OS/2)	RTL native	patched binutils	✅	✅ 72 units	✅ resolves*

*OS/2 link resolves all import symbols and produces a valid a.out; the final a.out→LX packaging uses emxbind (ported, builds on Linux) plus the redistributable emxl.exe runtime loader. See docs/os2_linking_solved.md.

DOS is 32-bit only (16-bit in progress). DOS support targets go32v2 (32-bit protected mode). 16-bit real-mode DOS (i8086-msdos) is under active development on a separate branch (i8086_work/) — the i8086 backend is a full backport from FPC 3.0, currently deep in Stage 4 (RTL system.pp compilation). It is not in any release yet.

Testing

test/run-tests.sh              # string + codepage + socket tests
test/test-tools.sh             # verify bundled tools (31 checks)
test/test-tool-fallback.sh     # verify 3-tier fallback (44 checks)
test/test-all-platforms.sh     # full 6-platform verification
test/test-os2-build.sh         # OS/2 build chain status

Test results

Test	Checks	Status
String baseline	65/65	✅ PASS
Codepage infrastructure	34/34	✅ PASS
Binary protocol safety	47/47	✅ PASS
Auto conversion	12/12	✅ PASS
Linux sockets	11/11	✅ PASS
String + socket total	169/169	ALL PASS
Cross-socket (DOS, win32, FreeBSD, OS/2)	4/4	✅ compile-verified
Full harness (run-tests.sh)	9/9	✅ ALL AVAILABLE TESTS PASSED
Tools (all platforms)	31/31	✅ PASS
Tool fallback	44/44	✅ PASS

Milestone status

• Phase 1: Codepage compiler support (4/4 items complete)
• Phase 2: go32v2 cherry-picks (3 fixes, gated)
• Phase 2: OS/2 cherry-picks (7 fixes, 44 RTL units, linking solved)
• Phase 2: i8086 — scoped and deferred to a future release (full backend port, not a fix; ~28K lines + 32 shared-file edits + PPU-format work + NASM/WLINK toolchain). See docs/i8086_scoping.md. r3 ships 32-bit DOS via go32v2.
• FPC text-mode IDE — self-contained 3-tier system: bundled bin/ide/fp + units (Tier 2), build-ide.sh from in-tree source (Tier 3), tools/get-ide.sh provisioner
• Lazarus 1.2.6 LCL — self-contained 3-tier system per widgetset: bundled units incl. form resources (Tier 2), build-lcl.sh from in-tree source (Tier 3), tools/get-lcl.sh provisioner. win32 verified (PE32 GUI .exe), gtk2 + qt built, nogui run-verified (headless). See docs/lazarus_lcl.md
• Phase 4: Prove it works — Mystic BBS v1.10 A38irc cross-compiles 56/56: 14/14 each on native Linux, win32, go32v2 DOS, and OS/2 (OS/2 links with all symbols resolved). Completing OS/2 required building 3 RTL units (crt, sockets, so32dll), fixing 2 upstream RTL bugs, and writing the first OS/2 TProcess implementation for fcl-process (upstream FPC never had one). See docs/mystic_build.md.
• [~] Phase 5: Release (tag 2.6.4irc-r3) — release docs, commit messages, and GitHub About text prepared in RELEASE-r3/; see MILESTONE-R3.md and RELEASE-r3/CHECKLIST.md.

Note: Phase 3 (AArch64/Apple Silicon) deferred to Option B — separate modern FPC track. See docs/ for the Modern Platform Bridge document. ARM64 is a compiler backend and cannot be added to 2.6.4irc as an RTL add-on.

Known warnings

ld: warning: ... has a LOAD segment with RWX permissions — this is a modern binutils (2.39+) security warning about FPC 2.6.4's linker scripts. The generated executables have segments that are both writable and executable, which is normal for this era of compiler. The warning is harmless and does not affect functionality.

License

Compiler: GPL v2 (same as upstream FPC). RTL/packages: modified LGPL. See LICENSE and src/rtl/COPYING.FPC. Bundled tools: GPL v3+ (source in lib/build-tools/).