VR_COMMS.C boot_860() shows the host boots the render board by streaming the
whole .MNG over the wire: args860 ("i860 50MHz and kicking"), a 40-byte
code860 packet holding the 7-word header {csize,dsize,bsize,cstart,dstart,
bstart,entry}, then the code/data/bss segments. cap7's preamble is therefore
a complete firmware image -- and a DIFFERENT BUILD than sda4/RPLIVE/VREND.MNG
(text 0x31440 vs 0x39ec0), which explains the residual global-address
mismatches (version skew) when replaying cap7 against the sda4 build.
The wire header also confirms the link layout from the protocol itself:
cstart=0xf0400000, dstart=0x00001000, bstart=0x0001f4a0, entry=0xf0400000.
Note the streamed "bss" content is NOT zeros (10685/14272 nonzero bytes).
extract_capfw.py reassembles the image (capfw7.mng + capfw7.bss, committed);
it boots in emu860 to 0xf040062c then needs op 0x0d (new ctrl-reg variant).
run_to_draw.py = marathon runner with board-stream dump.
Next: re-derive the hook addresses (main/dN_receive/allocator/...) for the
capture build and replay cap7 against its own firmware, version-matched.
Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>
processes the full wire boot incl. the downloaded PAZ/sfx module
ISA fixes, all derived from the toolchain's own .S<->.O pairs (AS860.ZIP:
OPTFLOAT/TRISTRIP/ZBUF32, plus DNC.O) and the firmware's linked COFF header:
- DATA_BASE = 0x1000 DEFINITIVE: VREND.MNG carries its original COFF header in
the file tail (.data vaddr 0x1000, .bss 0x1f940, entry 0xf0400000).
- Integer loads: even opcodes are register-indexed (EA = src2 + src1); op 4/5
size flag = instr bit0 (0 = ld.s 16-bit, 1 = ld.l 32-bit); ld.b/ld.s
sign-extend.
- Integer stores: st.s/st.l selected by offset bit0, same split-offset rule.
- FP loads/stores: FP register lives in the DEST field for both fld and fst
(fst does NOT use the integer split-store encoding); flag bits: bit0 =
auto-increment (base <- EA), bit1 1=.l/0=.d, bit2 = .q; .d/.q span register
pairs/quads. ~450 fld.d + ~300 fst.d were previously read/written 32-bit.
- bla (op 0x2d, was misdecoded as shrd): branch-on-LCC-and-add with the
sign-dependent LCC rule (src1<0 -> signed sum >= 0), so spent countdown
loops terminate. 335 bla instructions in the firmware.
- CORE ESCAPE (op 0x13): sub-op 1 = lock, 2 = calli, 7 = unlock. Previously
everything decoded as calli, so every spinlock acquire jumped to address 0 --
this was the phantom "exit stub" behind most earlier derails.
- f2b: IEEE overflow -> +/-inf instead of raising.
emu_main.py (new): runs the firmware's OWN main() (0xf0403f10) and feeds real
wire captures through a hooked dN_receive, so init/do_init/dispatch/handlers
all execute authentically. Provides the transputer-monitor environment
(processor id, DRAM region descriptors in the shared control block, sbrk/
shared-block seed slots) and hooks only the link primitives (bla busy-wait,
dN_mynode/dN_nodes/dN_receive/dN_send, putchar path, spinlocks, page allocator
+ virt->phys translator pending Tier-2 VRENDMON).
KEY DISCOVERY: the capture's args860/code860/data860/bss860 preamble is the
host DOWNLOADING an additional i860 module (the PAZ/sfx renderer layer, banner
"i860 50MHz") which installs the runtime handler tables and system objects.
Feeding it through the firmware's own handlers, the module loads and makes the
first IGC board-register writes. State: 834+ wire commands processed (module
download + init + create); first draw_scene sits at command 1568.
Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>
Env-gated hooks to continue the create()/jump-table investigation without
changing default behavior:
- EMU_DATA_BASE (default 0): overrides I860.DATA_BASE for the .data link base.
- EMU_INDEXED=1 (default off): makes EVEN integer load opcodes register-indexed
(EA = base + index), per the ground-truth `ld.l r30(r31),r31` in VR_REMOT.S.
Sweep finding (EMU_INDEXED=1): create() RETURNS at DATA_BASE=0xff0 making real
subroutine calls, confirming register-indexed loads + a ~0x1000 data base are
correct. Residual: do_init derails to (DATA_BASE+0x30) for base >= 0xfe0 while
create needs >= ~0xfe0 -- a single flat base can't satisfy both yet, pointing
to a segment/relocation nuance (or a separate do_init jump-table derail).
Details + repro in the tier-0 memory. Default behavior unchanged.
Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>
Worked the full-render marathon by tracing faults in the real VREND.MNG
firmware and matching them to the ground-truth AS860 assembly (VR_REMOT.S)
and C source (VR_REMOT.C). Six interpreter bugs found and fixed:
1. subs/subu direction: computed src2-src1; must be src1-src2 with
CC=(src1<src2). Corrupted every subtraction, compare and bounds-check.
2. logical CC: all i860 logicals (and/andnot/or/xor + .h) set CC=(result==0).
Had wrongly limited it to the AND family, so the `xor 0x0,rN,r0; bnc`
zero-test idiom spun forever.
3. STORE encoding (the big one): i860 stores encode the SOURCE register in
bits 15:11 (src1), not the dest field, and SPLIT the 16-bit offset across
bits 20:16 (high) + bits 10:0 (low). The old decode saved the wrong
register to the wrong offset, so function prologues never stored r1 and
every `bri r1` return jumped to 0.
4. ld.b/st.b: op 0x00/0x01 = ld.b, op 0x03 = st.b (byte). Proven by byte-scan
loops (r5 advanced by 1) and a save/restore pair at 0xf042b418 -> b430.
5. Mem page-span: r16/r32/w16/w32 crashed on 64KB page boundaries; now fall
back to byte access across the boundary.
6. fmlow.dd (FP subop 0x21): the i860 has no integer multiply, so ints are
ixfr'd into FP regs, multiplied via fmlow.dd, and fxfr'd back. Implemented
as a 32x32 -> 64 multiply across the destination register pair.
emu_replay.py now runs the source-accurate init sequence: velocirender_init
on the init(0) command, then do_init before the first real command. Result:
boot idles at 0xf0400590; velocirender_init returns; do_init runs to
completion (~9200 steps of real allocator / name-table / scene-root setup).
Remaining blocker (documented in the tier-0 memory): create()'s switch needs
register-indexed integer loads (VR_REMOT.S: `ld.l r30(r31),r31`) together
with the correct .data link base (~0x1000, not 0) -- the two errors currently
cancel for the immediate paths but break the indexed jump-table dispatch.
Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>
Feeds the real captured VelociRender wire (dpl3-revive/patha/*.raw.bin, from the
soft-renderer work) to the firmware's own command handlers in emu860 -- the path
to building a scene and rendering a frame with the board's own code.
- Parses captures via vrboard's Assembler (skips the .BTL boot, frames
action+payload). cap7 = a clean small scene (17 zones / 22 instances / 24
geometry / 1 view).
- Calls each command's handler directly with the payload pointer in r16 --
verified valid: create's prologue reads [r16+0]=type, [r16+4]=handle, i.e. the
raw wire layout (no CCB wrapping needed). Bypasses the un-emulated transputer.
- Confirmed WIRE-action -> handler map by function identity (create/flush/
dcs_link/list_add/draw_scene/statistics/set_texmap_texels).
Two blockers identified for a full frame (documented in the memory + README):
1. The dispatch jump table is indexed by an INTERNAL command code, not the
wire action (velocirender_input remaps wire->internal first, e.g. draw=9
->12, flush=3->30); the high-frequency per-frame commands (0x09, 0x1d
artics, 0x2a) still need that remap reversed.
2. init(0) must run first to set up the allocator/name-table/scene-root --
cold create() faults without it.
Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>
emu860.py -- an i860 interpreter (reuses the dis860 decoder) that executes the
real Division firmware. This is the foundation of the preservation-grade
emulator (run the board's own code, vs the GL bridge which interprets the wire).
- Boots VREND.MNG cleanly: i860 init (psr/dirbase/fsr), enables the MMU, then
idle-spins at 0xf0400590 waiting for a transputer interrupt (init complete).
Board-config regs modelled (0xfffff720=2, 0xfffff70c=1) via map_control().
- Call harness (cpu.call): invoke firmware functions directly, bypassing the
(un-emulated) transputer that normally drives the CCB.
- Correct memory map: .data/.bss linked LOW (DATA_BASE=0), so globals resolve.
- FP unit with double precision (register pairs): fadd/fsub/fmul/famov/frcp/
frsqr/fix/ftrunc/fgt/feq/fxfr/fiadd/fisub.
- Delay slots, control regs, sparse MMIO memory with trap/logging, tail-trace
and stopat debug aids.
draw_scene now runs real code (incl. a double int->float conversion) until it
needs accumulated scene state -- next step is replaying a captured wire command
sequence through the command dispatcher (jump table @0x47cb8) so the scene
builds and draw_scene emits the IGC coefficient stream (Tier-1 handoff).
Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>
Predator/IR vision: reverse-engineered from the original firmware and
confirmed by the build team -- it is the Division board's TEXTURE-VALUE RAMP
mode (a "check your texture maps" diagnostic the devs hijacked), NOT a
grayscale squash or a false-colour palette. Located in VREND.MNG (effect
handler @0xe6c0, wire action 0x1b, type -1 ON / -2 OFF); ramp colours from
VR_DRAW.C. Renderer reworked to match: vrview_gl now does the 4-ramp
lerp(color0,color1,luminance(texel)) in the mesh pass (grayscale+defog
removed). Live-rendered on a new night-clear arena egg; crew A/B verdict
pending.
Firmware-decomp toolchain (emulator/firmware-decomp/), all built from the
project's own artifacts and validated:
- coff860.py i860 COFF reader (symbols/sections), names match AS860 source
- derive860.py derives the i860 opcode map from matched .S<->.O pairs
- dis860.py i860 disassembler (98% on clean ground truth; proven on
VREND.MNG -- velocirender_statistics decodes correctly)
- sigmatch860.py reloc-invariant signature matcher onto the stripped image
- i860-encoding.md / FIRMWARE-SYMBOLS.txt / README.md
PVISION-IMPLEMENTATION-GUIDE.md: self-contained hand-off for the BT411 team.
HARDWARE-ARCHITECTURE.md + hardware-photos/ (15 board shots): the Division
VelociRender card is a 2-board stack driving a 3-processor pipeline --
INMOS IMS T425-J25S (comms/control, runs vrendmon.btl) + Intel i860 XP-50 (FP
geometry, runs vrender.mng) + Division PXPL IGC 5.2 ASIC with ~48x PXPL EMC
5.1 (UNC Pixel-Planes-5 SIMD array; "EMC" = the firmware's configEMCs) +
Analog Devices ADV7150 RAMDAC + NTSC. Plus the VWE Video Distribution Board
(P/N 1404: AMD MACH130 + 3x Brooktree Bt477) for the 3-VGA-head cockpit split.
Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>
CydandClaude Opus 4.8