Roflin
a5ca8b0cda
The whole gc_bba_test suite now passes on a real GameCube: Identity (device ID 04 02 02 00, HIPR, NWAYS), Registers, Reset/control, EXI integrity (speed sweep ok=[1,1,1,1,1,1], per-speed dump clean at all six indices, raw reg dump 0x17 in slot 0), Ethernet, and SPRAM/DMA -- at the real 27 MHz EXI rate. The one reported failure was t_raw_id, and it was not a fault: an earlier suite had already issued the NCRA reset that clears id_phase, after which address 0 correctly reads back NCRA. t_devid already guarded for this; t_raw_id did not, so a full run cried wolf. It now returns SKIP like t_devid, and both messages say reflash/reset the FPGA rather than power-cycle the console, which is what actually restores id_phase. CLAUDE.md records the device-ID fix and, importantly, that simulation CANNOT reproduce the bug it fixed -- bba_top passed the ID at EXI_HALF=1 beforehand, because sim's sync-to-EXI latency ratio does not match silicon closely enough to miss a 296 ns window. Anyone "simplifying" the ID back into the register file will keep a green suite and break hardware. Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>
re-bba-rb — on-console test suite (GameCube)
A .dol you run from Swiss that drives the adapter in Serial Port 1 and
reports pass/fail per test on the TV.
Build
Needs devkitPro's gamecube-dev group (devkitPPC + libogc). The devcontainer
installs it — if DEVKITPPC is unset, rebuild the container, since the
toolchain is added in .devcontainer/Dockerfile.
make # -> gc_bba_test.dol
Copy the .dol to your SD card (SD Gecko / SD2SP2) and launch it from Swiss.
Controls
| Button | |
|---|---|
| D-pad up/down | move |
| A | open a suite / rerun the selected test |
| X | run the selected suite |
| START | run everything |
| Y | clear all results |
| B | back |
What it tests
| Suite | Proves |
|---|---|
| Identity | device enumerates: 04 02 02 00, HIPR, NWAYS |
| Registers | PAR0–5, IMR writable and read back; IR is write-1-clear |
| Reset/control | NCRA RESET self-clears, SR holds |
| EXI integrity | 200 reads with no bit errors; which EXI clock indices work |
| Ethernet | MAC readback, 60-byte ARP transmit (TI), frame receive (RWP/RI) |
| SPRAM/DMA | ring descriptor is well-formed; reads ≥ 0x100 stream until CS |
Things that will bite you
The device ID is a ONE-SHOT. Address 0 returns 04 02 02 00 only until
the first NCRA reset clears id_phase in the gateware; after that it reads
back NCRA. That is correct — it matches the GC's own init order — but it means
the Identity test can only pass once per console power cycle. Run it before
the Reset suite. On a re-run the app reports SKIP with an explanation rather
than a misleading failure.
TI is not proof of transmission. It only means TXFrameDrain handed the
frame to the W5100. A frame can set TI and never reach the wire. The TX test
says so; to confirm the wire, capture on a PC or watch the RX test pick up a
reply.
The RX test needs traffic. It waits ~2 s for any frame. On an isolated
link with nothing talking it will fail legitimately — give the PC an address on
the same subnet (the ARP the TX test sends is aimed at 10.0.0.50, so
sudo ip addr add 10.0.0.50/24 dev <nic> makes the PC answer it and both tests
pass together).
Never over-clock a register read. Asking for N bytes and clocking more
leaves stale prefetched bytes queued and desynchronises the next transaction
— a deterministic every-Nth-read corruption that looks like a signal-integrity
fault. bba_read() clocks exactly len; don't "round up" for convenience.
TXDATA takes one byte per transaction. The register file's effective
address auto-increments per data byte, so a 4-byte write to 0x48 would spill
into 0x49–0x4B. bba_tx_bytes() does it correctly.
Build status
Builds clean (no warnings) with devkitPPC 16.1.0 / GCC 16 in the devcontainer:
gc_bba_test.dol, ~172 KB, entry 0x80003100.
.gitignore excludes the build products — run make to produce the .dol.