#!/bin/bash
# One MB89352 transport run: the 68000 selects a SCSI target and reads the disc
# itself (ROADMAP P4, first half).
#
#   tools/bench/scsi_run.sh [container.dlx]
#
# THE APPARATUS, AND ITS TWO SUBSTITUTIONS, BOTH DELIBERATE AND BOTH LABELLED.
#
# 1. THE BOARD.  `x68000 -exp1 cz6bs1`, which is what FINDINGS 42.5 says to
#    benchmark and never `x68ksupr` -- the Super/XVI internal SCSI is PIO-only in
#    MAME (`// TODO: duplicate DMA glue from CZ-6BS1`), so it would measure a
#    fallback the real machine does not have.
#
# 2. THE BOOT ROM.  MAME refuses to instantiate the card without an 8 KB
#    `scsiexrom.bin` (CRC 7be488de), which is not in this tree and is not on this
#    machine.  This script writes a ZERO-FILLED placeholder into its own rompath,
#    so the user's romset is untouched, and MAME prints WRONG CHECKSUMS as it
#    should.  That is honest HERE and would not be everywhere: the player drives
#    the SPC registers directly and never executes a byte of that ROM -- which
#    was already the plan in docs/BENCHMARK.md item 4, long before the ROM turned
#    out to be missing.  DO NOT reuse this rompath for anything that boots from
#    the card or calls SCSI IOCS; those DO execute it.
#
# WHAT A GREEN RUN MEANS: the 68000 reached the SPC, selected a target, issued
# READ(10) twice -- at LBA 0 and at a non-zero LBA -- and both came back byte for
# byte identical to the host's copy of the same image.  No IOCS, no host in the
# transfer path.
#
# WHAT IT DOES NOT MEAN: anything at all about RATE.  MAME's device models are
# functional, not transfer-timing accurate (docs/BENCHMARK.md), and 42.5 reads
# its DMAC configured in wall-clock attotimes rather than per-operand cycles.
# `W` -- clocks stolen per delivered byte, the project's largest open number --
# is untouched by this script.
set -e
cd "$(dirname "$0")/../.."
DLX=${1:-tmp/rc_fr_singe_scsi_span.dlx}

# The container's frame records, laid out as a disc.  prep_stream.py already
# writes exactly this file for the ring rig, so the SCSI volume and the host-file
# pipe carry byte-identical bytes and a difference between the two rigs cannot be
# a difference in what they are reading.
[ -f tmp/stream_disk.bin ] || python3 tools/bench/prep_stream.py "$DLX" > /dev/null
if [ ! -f tmp/dlxdisk.chd ] || [ tmp/stream_disk.bin -nt tmp/dlxdisk.chd ]; then
  python3 - <<'PY'
d = open("tmp/stream_disk.bin", "rb").read()
n = (len(d) + 511) // 512
open("tmp/dlxdisk.img", "wb").write(d + b"\0" * (n * 512 - len(d)))
print(f"  disc image: {len(d)} B of records -> {n} sectors")
PY
  rm -f tmp/dlxdisk.chd
  chdman createhd -i tmp/dlxdisk.img -o tmp/dlxdisk.chd -ss 512 > /dev/null 2>&1
fi

mkdir -p tmp/p4roms/x68k_cz6bs1
[ -f tmp/p4roms/x68k_cz6bs1/scsiexrom.bin ] || \
  head -c 8192 /dev/zero > tmp/p4roms/x68k_cz6bs1/scsiexrom.bin

tools/vasm/vasmm68k_mot -Fbin -o tmp/scsigate.bin src/player/scsigate.s > /dev/null

# stdbuf -oL: without it a long MAME run is unobservable until it exits, and a
# run that is merely finishing looks exactly like one that is wedged (34.1).
( cd tmp && SDL_VIDEODRIVER=dummy stdbuf -oL timeout -k 5 300 \
    mame x68000 -bios ipl10 -exp1 cz6bs1 \
    -rompath "$HOME/mame/roms;./p4roms" -hard dlxdisk.chd \
    -ramsize 2M -video soft -window -sound none -nothrottle -plugins \
    -autoboot_script ../tools/bench/scsi.lua \
    -seconds_to_run 60 > scsi_run.log 2>&1 )
# A run that never reached the report must fail as that, not as a missing line.
grep -aq "^\[SCSI\] done" tmp/scsi_run.log || {
  echo "FAIL: the SCSI gate did not finish -- no completion marker."
  tail -8 tmp/scsi_run.log; exit 1; }
grep -a "^\[SCSI\]" tmp/scsi_run.log | grep -avE "^\[SCSI\] +[0-9]+:" \
  | sed 's/^\[SCSI\] /  /'

# THE ASSERTIONS.  Printing a result and gating on it are different things, and
# this project has already paid once for a stage that printed.
grep -aq "ANSWERED 60 of 64" tmp/scsi_run.log || {
  echo "FAIL: the card's register window is no longer 60 of 64 addresses."
  echo "      The MB89352 omits TMOD (index 3) and EXBF (index 15) where the"
  echo "      MB87030 has them, and MAME leaves HOLES rather than shifting the"
  echo "      later indices down -- which is what puts DREG at \$EA0015. If this"
  echo "      moved, src/player/scsi.i's whole register map moved with it."
  exit 1; }
grep -aq "READ(10) OK: 4096 B from LBA 0" tmp/scsi_run.log || {
  echo "FAIL: the 68000 did not read LBA 0 off the SCSI volume byte-exact."
  exit 1; }
grep -aq "READ(10) OK: 2048 B from LBA 1000" tmp/scsi_run.log || {
  echo "FAIL: the read at a NON-ZERO LBA did not match. A driver that emits a"
  echo "      malformed LBA field still passes LBA 0, because zero is what a"
  echo "      malformed field usually is -- so this is the half that matters."
  exit 1; }
grep -aq "scsi_read FAILED" tmp/scsi_run.log && {
  echo "FAIL: a read reported an error."; exit 1; }
exit 0