Glossary

Concise definitions of the Amix-, Amiga-, and SVR4-specific terms that recur across these docs. Each entry is one or two lines and links to the page that covers the term in depth. Confidence tags (✅ verified, 🟡 community-reported, 🔴 unverified/disputed) carry over from the research brief — they are not upgraded here.

Entries are alphabetical. Acronyms sort by their letters (so "RDB" sits under R, "s5" under S).

3B2

AT&T's WE32x00-based minicomputer line whose SVR4 codebase Commodore reportedly ported, for licensing-cost reasons, rather than starting from a pre-existing 68k port 🟡 (community-reported — amigaunix.com hedges "it appears that"; corroborated by EAB/datagubbe, no primary citation). The 3B2 lineage is the suspected reason Amix defaults to the s5 filesystem at install even though everyone uses UFS 🟡. See How Amix works: overview.

/usr/sys

The kernel build tree. Amix ships the kernel as compiled object libraries under /usr/sys; you relink /unix here ✅. Some .o files come with source, others are object-only. Driver sources/objects are dropped into a subdir under /usr/sys and added to that dir's makefile ✅. See the kernel build process and the driver model.

AUTOCONFIG

The Amiga bus protocol that assigns Zorro II board addresses at every reset ✅. Amix reads the assigned addresses through the kernel's autocon() interface; Zorro II only ✅. The on-disk nibble format (two nibbles per logical byte, upper nibble D15–D12, most fields ones-complement) is decoded by the lszorro scanner ✅. See Zorro AutoConfig for driver authors.

autocon()

The Amix-specific kernel call a driver uses to discover its Zorro II board: autocon(product_id, dev, &board, &dummy) 🟡 (repo-confirmed). Used by the va2000 and hydra drivers. See Zorro AutoConfig. Distinct from the boot-time init tables init_tbl[]/io_init[] declared in kernel.c.

Amix

Commodore's port of AT&T UNIX System V Release 4 (SVR4) to the 68030 Amiga; kernel platform string m68k-cbm-sysv4 ✅. Monolithic kernel, no AmigaOS compatibility layer ✅. It drives the native chipset through its own kernel drivers — the bitplane console and /dev/screen, on which the stock mono X server runs — never through AmigaOS libraries ✅. See the overview.

cdevsw / bdevsw

The two kernel device switch tables, declared in conf.h and instantiated in kernel.c, indexed by major number ✅. cdevsw[] is for character devices (d_open/d_close/d_read/d_write/d_ioctl/d_mmap/d_segmap/d_poll/d_xpoll/d_xhalt, plus d_ttys, d_str, d_flag); bdevsw[] is for block devices (d_open/d_close/d_strategy/d_print/d_size/d_xpoll/d_xhalt/d_flag) ✅. Unused slots get nodev, notty, nostr, or nullflag. See the driver model.

clist

The SVR4 character-list queue used to buffer slow byte-stream I/O; manipulated with getc()/putc() ✅. The parallel-port driver (par.c) in the Ditto paper uses a clist for its output queue ✅. See writing a char driver.

DLPI

Data Link Provider Interface — the SVR4 STREAMS service interface a link-layer network driver exposes (messages DL_INFO_REQ, DL_BIND_REQ, DL_UNITDATA_REQ) ✅. The hydra NE2000 driver is a DLPI STREAMS driver registered at cdevsw slot 47 ✅. See writing a STREAMS driver and networking.

elf2brel

The converter in the kernel boot//stand/ directory that turns the (natively built) ELF kernel into Amix's boot ("brel") format ✅. Part of the on-box kernel build: native cc/GCC → ELF → elf2brel → make force ✅ (used by e.g. the hydra driver). See the toolchain.

HAT

Hardware Address Translation — the SVR4 MMU abstraction layer ✅. Amix uses the full 68030 MMU through HAT ✅; the install kernel even carries the panic string hat_vtokp_prot: user addr in kernel space ✅. The MMU requirement is why Amix needs MMU emulation in WinUAE, and why the stock kernel cannot run on MMU-less CPUs or the 68040/68060 (whose MMU it predates) ✅; the 040/060 port kernels can ✅. See the kernel architecture, hardware, and the current 040/060 status.

kernel.c

The kernel configuration file (master.d/kernel.c), provided in source, that holds the device switch tables (cdevsw[]/bdevsw[]), the interrupt tables (int2_tbl[], a level-6 table), and the boot-time init table (init_tbl[]/io_init[]) ✅. Adding a driver means editing kernel.c to add the entries, then rebuilding ✅. The full original file is not publicly archived; its schema is inferred from the Ditto paper plus the modern repos 🔴. See the driver model and kernel build.

m68k-cbm-sysv4

The Amix kernel platform / configure triple string ✅. GNU autodetect on Amix instead reports m68k-unknown-sysv4, so cross-toolchains must set the triple explicitly ✅. See the overview and toolchain.

major / minor

The two numbers that identify a /dev node: the major selects the driver (an index into cdevsw[]/bdevsw[]), the minor selects the sub-device; the kernel knows only the numbers, not the name ✅. Examples from the Ditto paper: /dev/console = char major 0 minor 0; /dev/dsk/c0d0s1 = block major 18 minor 1 (SCSI driver); /dev/fd0 = block major 16; /dev/par = char major 21 ✅. You create a node with mknod /dev/<name> c|b <major> <minor> ✅. See the device list and driver model.

miniroot

The minimal root filesystem (s5) on the install root floppy (amix_21_root.adf) that mounts during installation and runs the installer ELF binaries and shell scripts ✅. It carries the partition/install logic, the installer programs (cpio, fsck, dd, amixpkg, …), and viper_kludge ✅. See the root floppy anatomy and the install walkthrough.

pkgadd

The SVR4 package installer (with siblings pkgmk, pkgproto, pkgtrans, pkginfo, pkgrm) used to install software on Amix ✅. The root.adf install scripts drive it through the amixpkg wrapper (amixpkg -i -m -d -r /mnt -y standard) — which is on the install media only, not the installed system ✅ (its "flaky/broken" reputation 🟡 is partly a corrupt-database defect on the stock image, not the raw tools). pkgproto also omits symlinks 🟡. Michael Parson's AmixBP re-bundles 40+ .pkgs on amigaunix.com/downloads 🟡. See package management for the /var/sadm database internals, and the kernel architecture and toolchain.

RDB

Rigid Disk Block — the Amiga's on-disk partition scheme, which Amix uses for its hard disk ✅. The default install lays out root (/), swap, a 2 MB boot/bootstrap partition (BOOTSIZE=2 MB → BOOTLEN = BOOTSIZE*2048 blocks), and data ✅; keep partitions ≲1 GB 🟡. The exact RDB partition type IDs Amix uses are not documented 🔴. See filesystems and disks.

relocunix / rdbunix

The relinked Amix kernel image. The 1990 Ditto paper calls it rdbunix; modern 2.1 systems and repos call it relocunix — a historical rename (verify per version 🟡). After building you cp relocunix /stand, then make bootpart KERNEL=relocunix writes it to the boot partition ✅. See the kernel build process.

RTG

ReTargetable Graphics — driving a third-party graphics card instead of the Amiga's built-in display. On Amix this is the va2000 char framebuffer driver (/dev/va2000, char major 68) plus the xrtg X11R5 server Xrtg ✅. See X11 RTG drivers and X11 and the desktop.

s5

The System V (s5) filesystem — the default choice offered by the Amix installer, in both the prompt ([s5]) and the script's empty-input branch ✅. UFS is the community recommendation 🟡 but must be typed explicitly; it is not the script default (a claim corrected 2026-07-19). The s5 default is likely a 3B2-lineage artifact 🟡, and on some ROMs s5 is the only bootable root (ROOT_FSYS="s5" # Johann ROM can only boot s5 filesystem) 🟡. See filesystems and disks.

spl / splN

The SVR4 interrupt-priority masking primitives a driver uses to protect critical sections (spl2()/splx(), etc.) ✅. The Ditto par driver wraps its critical regions with splpar(), which equals spl2() ✅. See writing a char driver.

STREAMS

The SVR4 modular I/O framework used for networking; a STREAMS driver is a distinct third driver class (a special character driver carrying a streamtab, the d_str field in cdevsw) ✅. Amix networking (TCP/IP, DLPI) is STREAMS-based ✅. See writing a STREAMS driver and networking.

Superkickstart

The A3000UX bootstrap ROM ("Superkickstart 1.4") that chooses what to boot at power-on: hold the right mouse button to load an AmigaOS Kickstart, or by default boot Amix from SCSI ✅. See the boot process and hardware.

SVR4

AT&T UNIX System V Release 4 — the operating system Amix is a port of ✅. Brings STREAMS networking, TLI plus BSD sockets, POSIX.1, init//etc/inittab/run levels, and the pkgadd packaging tools ✅. See the overview and kernel architecture.

UFS

The Berkeley Fast File System (UFS), the community-recommended Amix filesystem 🟡. The installer scripts do not default to it — the prompt is [s5] and empty input selects s5; ufs must be typed explicitly ✅ (corrected 2026-07-19; this page previously claimed the opposite). The install miniroot on the stock root floppy is an s5 filesystem, not UFS ✅ (root disk anatomy). Contrast s5. See filesystems and disks.

viper_kludge

A patch (by Frank "Crash" Edwards) shipped on the root floppy that pokes kernel memory so non-standard tape drives (e.g. the Archive Viper 2150S) work during install ✅. Its own README warns it is incompatible with the A3070/Caliper/Wangtek/Sankyo drives ✅. See the install walkthrough.

Zorro II / III

The Amiga expansion bus. Stock Amix drivers are Zorro II only: AutoConfig puts Zorro III boards at 0x40000000 and above, outside the kernel's identity-mapped low 1 GB, so a driver that dereferences the AutoConfig address reaches only Zorro II boards; a driver that maps the board with sptalloc() reaches Zorro III ✅ (see the Zorro III correction). Board addresses are assigned by AUTOCONFIG at reset ✅. See hardware, Zorro AutoConfig, and the quirks list.

See also

• How Amix works: overview — the one-page mental model that ties these terms together
• Kernel architecture — where the switch tables, HAT, and STREAMS live
• The device-driver model — majors/minors, cdevsw/bdevsw, adding a driver
• Reference: device list — concrete major/minor assignments

Sources

• sources/research-brief.md — sections 1, 2, 3, 4, 5, 6, 7, 9, 11 (the grounding source of every definition above); the stock-only scope of the HAT entry's CPU limit per the 040/060 status page
• Michael Ditto, Writing Amix Device Drivers, 1990 European Amiga Developer's Conference — driver model, cdevsw/bdevsw, majors/minors, spl/clist, rdbunix (the Ditto paper)
• amix_21_root.adf analysis via tools/inspect-adf.sh — miniroot (s5; corrected 2026-07-05), viper_kludge, install/partition logic, relocunix/make bootpart
• amix_21_boot.adf analysis via tools/inspect-adf.sh — compressed kernel, HAT panic string
• The native-chipset display path (Amix entry): research brief §21 (the screen manager's DisplayScreen()/NewBitmap chip-RAM bitmap on the native display) and jusii/amix-z3660rtg docs/X-INSTALL-RTG.md (the console login on the chipset screen; the stock startx on the native chipset); the stock cdevsw[] row 10 screen on the major-number registry
• Driver repos: asokero/va2000-amix, asokero/xrtg-amix, asokero/lszorro-amix, isoriano1968/hydra-amix — autocon(), RTG//dev/va2000, DLPI/STREAMS, elf2brel, m68k-cbm-sysv4
• amigaunix.com — community-reported (🟡) details: s5-vs-UFS default rationale, amixpkg flakiness, AmixBP