symbols: the four WRAM names the whole-map grid reads

resolve_wram.py is a second reading of the disassembly beside gen_symbols.py:
it walks ram/wram.asm with a cursor that is only ever live while anchored on an
address symbols.rs already pins, re-derives 40 of the 63 it carries with no
disagreement, and emits an address only when a pinned one after it agrees too.
wOverworldMap, wCurMapTileset, wTilesetBank and wTilesetBlocksPtr come out of
that pass; no address is hand-written and nothing else in the table moves.
This commit is contained in:
claude 2026-09-22 03:17:20 +00:00
parent 1a3cfb714a
commit 320b05ecee
3 changed files with 424 additions and 0 deletions

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@ -16,6 +16,7 @@ pub mod ram {
pub const wSpriteStateData1: u16 = 0xc100; // 49408
pub const wSpriteStateData2: u16 = 0xc200; // 49664
pub const wTileMap: u16 = 0xc3a0; // 50080
pub const wOverworldMap: u16 = 0xc6e8; // 50920
pub const wTopMenuItemY: u16 = 0xcc24; // 52260
pub const wTopMenuItemX: u16 = 0xcc25; // 52261
pub const wCurrentMenuItem: u16 = 0xcc26; // 52262
@ -59,6 +60,7 @@ pub mod ram {
pub const wCurMap: u16 = 0xd35e; // 54110
pub const wYCoord: u16 = 0xd361; // 54113
pub const wXCoord: u16 = 0xd362; // 54114
pub const wCurMapTileset: u16 = 0xd367; // 54119
pub const wCurMapHeight: u16 = 0xd368; // 54120
pub const wCurMapWidth: u16 = 0xd369; // 54121
pub const wCurMapConnections: u16 = 0xd370; // 54128
@ -68,6 +70,8 @@ pub mod ram {
pub const wSignCoords: u16 = 0xd4b1; // 54449
pub const wSignTextIDs: u16 = 0xd4d1; // 54481
pub const wNumSprites: u16 = 0xd4e1; // 54497
pub const wTilesetBank: u16 = 0xd52b; // 54571
pub const wTilesetBlocksPtr: u16 = 0xd52c; // 54572
pub const wTilesetCollisionPtr: u16 = 0xd530; // 54576
pub const wTilesetTalkingOverTiles: u16 = 0xd532; // 54578
pub const wNumHoFTeams: u16 = 0xd5a2; // 54690

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@ -182,6 +182,24 @@ EXTRA_RAM = (
# standing behind a desk can be talked to at all: none of the four tiles around either of
# them is walkable.
'wTilesetTalkingOverTiles',
# The whole-map walkability grid (docs/design/macros.md section 15).
#
# LoadTileBlockMap copies the loaded map out of its ROM bank into wOverworldMap
# as one byte per 4x4-tile block, in rows of wCurMapWidth + MAP_BORDER * 2 with
# the map itself three rows and three columns in, so the blocks of the current
# map are a WRAM read rather than a ROM one. wCurMapTileset keys the tile-pair
# collision lists (CheckForTilePairCollisions). wTilesetBank and
# wTilesetBlocksPtr are the tileset header's blockset: 16 bytes per block id,
# four rows of four tile ids, which DrawTileBlock indexes exactly that way --
# and it is not in bank 0, which is why the memory seam grew a bank-aware ROM
# read for it. All four are resolved the same way every other name here is;
# services/flysim/tools/resolve_wram.py is the second reading of them, from
# ram/wram.asm at this commit, and it re-derives 40 of the addresses this table
# already carries before it emits one of these four.
'wOverworldMap',
'wCurMapTileset',
'wTilesetBank',
'wTilesetBlocksPtr',
)

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@ -0,0 +1,402 @@
"""Resolve WRAM symbol addresses out of a pret/pokered checkout, and verify the pinned ones.
`gen_symbols.py` owns `symbols.rs` and takes its addresses from the prototype's
already-generated table; it refuses a hand-written address. Section 15 of
`docs/design/macros.md` needs four symbols that table does not carry
(`wOverworldMap`, `wCurMapTileset`, `wTilesetBank`, `wTilesetBlocksPtr`), and a
hand-computed address is exactly what neither script will take. So this tool
does the same job the disassembly's own `.sym` would, from `ram/wram.asm`:
* it walks the file in order, keeping a byte cursor;
* the cursor is **only ever live while it is anchored**: it is set from a symbol
`symbols.rs` already pins, and any declaration form this tool cannot evaluate
exactly kills it until the next pinned symbol revives it. An unanchored region
can therefore not produce a number at all, rather than producing a wrong one;
* every pinned symbol it reaches while live is checked against `symbols.rs`, and
a single disagreement is a failure with no output. A resolved symbol is only
reported when the run also re-derived the *next* pinned symbol after it, so
each answer is bracketed by two addresses the table already carries.
Usage (read-only; `--emit` rewrites the `ram` block of symbols.rs in place):
python3 services/flysim/tools/resolve_wram.py --pokered <checkout> [--emit]
"""
from __future__ import annotations
import argparse
import math
import re
from pathlib import Path
SYMBOLS = (
Path(__file__).resolve().parents[1] / 'crates/flybrain-gb/src/pokemon_red/symbols.rs'
)
#: The symbols this run is for, with why the macro layer needs each one. Every
#: one is checked to be bracketed by two pinned addresses before it is emitted.
WANTED = {
# The current map's block ids, as LoadTileBlockMap copies them out of the
# map's ROM bank: rows of (width + MAP_BORDER * 2) bytes, the map itself
# offset by three rows and three columns. This is what makes a whole-map
# walkability grid a WRAM read rather than a ROM one.
'wOverworldMap': 'the loaded map, one byte per 4x4-tile block',
# Which tileset the loaded map uses: the tile-pair collision lists are keyed
# by it (CheckForTilePairCollisions).
'wCurMapTileset': 'the loaded map tileset id',
# The tileset header's blockset: a bank byte and a little-endian pointer at
# 16 bytes per block, four rows of four tile ids (DrawTileBlock). The bank is
# not bank 0, so this is the read the memory seam grew a bank for.
'wTilesetBank': 'the ROM bank the blockset lives in',
'wTilesetBlocksPtr': 'blocks to tiles, 16 bytes per block',
}
def pinned(text: str) -> dict[str, int]:
"""Every address `symbols.rs` carries today, by symbol name."""
return {
name: int(value, 16)
for name, value in re.findall(r'pub const (w\w+): u16 = 0x([0-9a-f]{4});', text)
}
def constants(root: Path) -> dict[str, int]:
"""Every `DEF NAME EQU <expression>` the declarations below need.
Resolved by repeated passes rather than in one, because the decomp defines
constants in terms of each other (`SURROUNDING_WIDTH EQU SCREEN_BLOCK_WIDTH *
BLOCK_WIDTH`). A name whose expression never becomes evaluable is simply left
out, which kills the cursor at any declaration that uses it.
"""
pending: dict[str, str] = {}
sources = sorted((root / 'constants').glob('*.asm')) + sorted(
(root / 'constants').glob('*.inc')
)
for path in sources:
for name, value in re.findall(
r'^\s*(?:DEF|def)\s+(\w+)\s+(?:EQU|equ)\s+([^;\n]+)', path.read_text(), re.M
):
pending.setdefault(name, value.strip())
out: dict[str, int] = {}
while pending:
progressed = False
for name in list(pending):
try:
out[name] = size_of(pending[name], out)
except Unevaluable:
continue
del pending[name]
progressed = True
if not progressed:
break
return out
def number(token: str) -> int:
token = token.strip()
if token.startswith('$'):
return int(token[1:], 16)
if token.startswith('%'):
return int(token[1:], 2)
return int(token, 10)
class Unevaluable(Exception):
"""A declaration this tool will not guess the size of."""
def size_of(expression: str, known: dict[str, int]) -> int:
"""Bytes in a `ds`/`EQU` expression: the decomp's own arithmetic, nothing else.
`$`/`%` literals and the constants resolved so far are substituted, the
`tiles` unit is a factor of sixteen, and what is left must be plain
arithmetic over integers -- so a name this tool has not resolved, a function
call or anything else raises [`Unevaluable`] instead of becoming a guess.
"""
expression = expression.split(';')[0].strip()
if not expression:
raise Unevaluable('empty')
scale = 1
if expression.endswith('tiles'):
expression = expression[: -len('tiles')].strip()
scale = 16 # one 8x8 2bpp tile is 16 bytes
def substitute(match: re.Match[str]) -> str:
token = match.group(0)
if token[0] in '$%':
return str(number(token))
if token in known:
return str(known[token])
raise Unevaluable(token)
substituted = re.sub(r'\$[0-9A-Fa-f_]+|%[01_]+|[A-Za-z_]\w*', substitute, expression)
if not re.fullmatch(r'[\d\s()+\-*/]+', substituted):
raise Unevaluable(expression)
try:
value = eval(substituted, {'__builtins__': {}}, {}) # arithmetic only, checked above
except (SyntaxError, ZeroDivisionError, TypeError) as error:
raise Unevaluable(expression) from error
if not isinstance(value, int):
raise Unevaluable(expression)
return value * scale
def macro_sizes(root: Path, known: dict[str, int]) -> dict[str, int]:
"""Sizes of the RAM struct macros, counted from their own declarations."""
out: dict[str, int] = {}
for path in sorted((root / 'macros').glob('*.asm')):
text = path.read_text()
for match in re.finditer(r'^MACRO\??\s+(\w+)\n(.*?)^ENDM', text, re.M | re.S):
name, body = match.group(1), match.group(2)
total = 0
for line in body.splitlines():
line = line.split(';')[0].strip()
# A struct macro labels each field with its argument
# (`\\1YCoord:: db`), so the label is stripped and the
# declaration after it is what reserves the bytes.
line = re.sub(r'^[\\\w{}:.\d]+::\s*', '', line)
if not line or line.startswith(('IF', 'ELSE', 'ENDC', 'ASSERT')):
continue
if re.match(r'^\w+::?$', line):
continue
if line.startswith('db'):
total += max(1, len([part for part in line[2:].split(',') if part.strip()]))
elif line.startswith('dw'):
total += 2 * max(1, len([p for p in line[2:].split(',') if p.strip()]))
elif line.startswith('ds '):
try:
total += size_of(line[3:], known)
except Unevaluable:
total = None
break
else:
total = None
break
if total is not None:
out[name] = total
return out
def walk(
root: Path, table: dict[str, int], known: dict[str, int], verbose: bool = False
) -> tuple[dict[str, int], list[str], int]:
"""Resolve every symbol of wram.asm the anchored cursor can reach exactly."""
macros = macro_sizes(root, known)
lines = (root / 'ram/wram.asm').read_text().splitlines()
cursor: int | None = None
resolved: dict[str, int] = {}
# Symbols counted since the last pinned anchor, held back until a pinned
# address after them agrees.
pending_run: dict[str, int] = {}
order: list[str] = []
checked = 0
problems: list[str] = []
lost: list[str] = []
# UNION frames: (start address, widest branch so far, whether a branch was
# unevaluable). A frame whose start is unknown, or any one of whose branches this
# tool could not size, poisons the whole union: what the section advances by is
# the widest branch, so one branch it cannot measure means it cannot measure any.
unions: list[tuple[int | None, int, bool]] = []
index = 0
while index < len(lines):
raw = lines[index]
index += 1
line = raw.split(';')[0].strip()
if not line:
continue
if line.startswith('SECTION'):
# A section's address comes from the linker, not the source. WRAM0
# sections are packed in declaration order, so the cursor carries on
# -- and the next address `symbols.rs` pins is what tests that: any
# padding the linker inserted would land as a MISMATCH and this tool
# would emit nothing.
continue
if line == 'UNION':
unions.append((cursor, 0, False))
continue
if line == 'NEXTU':
if not unions:
cursor = None
continue
start, widest, poisoned = unions.pop()
poisoned = poisoned or start is None or cursor is None
if not poisoned:
widest = max(widest, cursor - start)
unions.append((start, widest, poisoned))
cursor = start
continue
if line == 'ENDU':
if not unions:
cursor = None
continue
start, widest, poisoned = unions.pop()
if poisoned or start is None or cursor is None:
cursor = None
continue
cursor = start + max(widest, cursor - start)
continue
if line.startswith(('FOR ', 'REPT ')):
# Evaluate the body only when every line of it has a known size.
head = line.split(None, 1)[1]
# `REPT n`, `FOR v, stop` and `FOR v, start, stop`: rgbasm's own
# three forms, and the third iterates stop - start times.
arguments = [part.strip() for part in head.split(',')]
count_token = arguments[-1]
start_token = arguments[-2] if line.startswith('FOR ') and len(arguments) == 3 else None
body: list[str] = []
depth = 1
while index < len(lines):
inner = lines[index].split(';')[0].strip()
index += 1
if inner.startswith(('FOR ', 'REPT ')):
depth += 1
if inner == 'ENDR':
depth -= 1
if depth == 0:
break
body.append(inner)
try:
count = size_of(count_token, known)
if start_token is not None:
count -= size_of(start_token, known)
per = 0
for inner in body:
per += declaration_size(inner, known, macros)
if cursor is not None:
cursor += count * per
except Unevaluable:
if cursor is not None:
lost.append(f'line {index}: {line}')
cursor = None
pending_run.clear()
continue
label = re.match(r'^(w\w+)::', line)
if label is not None:
name = label.group(1)
if name in table:
if cursor is not None and cursor != table[name]:
problems.append(
f'{name}: wram.asm gives ${cursor:04x}, symbols.rs pins ${table[name]:04x}'
)
pending_run.clear()
elif cursor is not None:
checked += 1
# Everything counted since the last anchor is now bracketed
# by two addresses the table already carries.
resolved.update(pending_run)
order.extend(pending_run)
pending_run.clear()
else:
if verbose:
lost.append(f'cold anchor at {name} (line {index})')
pending_run.clear()
cursor = table[name]
elif cursor is not None:
pending_run[name] = cursor
line = line[label.end() :].strip()
if not line:
continue
if line.endswith('::') or re.fullmatch(r'\.\w+', line):
continue
try:
if cursor is not None:
cursor += declaration_size(line, known, macros)
except Unevaluable:
if cursor is not None:
lost.append(f'line {index}: {line}')
cursor = None
pending_run.clear()
if verbose:
for entry in lost:
print(f'UNEVALUABLE {entry}')
return resolved, problems, checked
def declaration_size(line: str, known: dict[str, int], macros: dict[str, int]) -> int:
"""Bytes one declaration line reserves, or [`Unevaluable`]."""
line = line.split(';')[0].strip()
if not line or line.endswith('::') or line.startswith(('ENDSECTION', 'ASSERT', 'ENDR')):
return 0
# Any label, including the `{02d:n}` interpolations a FOR body labels its
# iterations with; what reserves the bytes is the declaration after it.
line = re.sub(r'^[\\\w{}:.\d]+::\s*', '', line)
if not line:
return 0
if line == 'db':
return 1
if line == 'dw':
return 2
if line.startswith('db '):
return max(1, len([part for part in line[3:].split(',') if part.strip()]))
if line.startswith('dw '):
return 2 * max(1, len([part for part in line[3:].split(',') if part.strip()]))
if line.startswith('ds '):
return size_of(line[3:], known)
if line.startswith('flag_array '):
return math.ceil(size_of(line[len('flag_array ') :], known) / 8)
head = line.split(None, 1)[0]
if head in macros:
return macros[head]
raise Unevaluable(line)
def main() -> None:
parser = argparse.ArgumentParser(description=__doc__)
parser.add_argument('--pokered', type=Path, required=True)
parser.add_argument('--verbose', action='store_true', help='name every declaration it will not size')
parser.add_argument('--emit', action='store_true', help='write the new addresses into symbols.rs')
args = parser.parse_args()
text = SYMBOLS.read_text()
commit = re.search(r'POKERED_COMMIT: &str = "([0-9a-f]{40})"', text)
if commit is None:
raise SystemExit('symbols.rs carries no POKERED_COMMIT')
head = (args.pokered / '.git/HEAD').read_text().strip()
if head.startswith('ref:'):
head = (args.pokered / '.git' / head.split()[1]).read_text().strip()
if head != commit.group(1):
raise SystemExit(
f'checkout is at {head}, symbols.rs pins {commit.group(1)}: two revisions of the '
'disassembly renumber RAM relative to each other'
)
table = pinned(text)
known = constants(args.pokered)
resolved, problems, checked = walk(args.pokered, table, known, args.verbose)
if problems:
for problem in problems:
print(f'MISMATCH {problem}')
raise SystemExit('the walk disagrees with symbols.rs; nothing emitted')
print(f'{checked} of {len(table)} pinned addresses re-derived from wram.asm, no disagreement')
missing = [name for name in WANTED if name not in resolved]
if missing:
raise SystemExit(f'unanchored, so not resolved: {", ".join(missing)}')
for name in WANTED:
print(f'{name} = ${resolved[name]:04x} ({WANTED[name]})')
if not args.emit:
return
block = re.search(r'(pub mod ram \{\n)(.*?)(\n\}\n)', text, re.S)
if block is None:
raise SystemExit('no ram block in symbols.rs')
rows = []
for row in block.group(2).splitlines():
name = re.match(r'\s*pub const (w\w+): u16 = 0x([0-9a-f]{4});', row)
if name is None:
continue
rows.append((int(name.group(2), 16), name.group(1)))
for name in WANTED:
if name not in table:
rows.append((resolved[name], name))
rows = sorted(set(rows))
width = max(len(name) for _, name in rows)
body = '\n'.join(
f' pub const {name}: u16 = 0x{address:04x};'.ljust(width + 31)
+ f'// {address}'
for address, name in rows
)
SYMBOLS.write_text(text[: block.start(2)] + body + text[block.end(2) :])
print(f'symbols.rs: {len(rows)} addresses written')
if __name__ == '__main__':
main()