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yaze/docs/public/reference/SYMBOL_FORMAT.md

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# ALttP Symbol File Format
Documentation for importing disassembly symbol files into YAZE.
**Source:** `~/Code/alttp-gigaleak/DISASM/jpdasm/symbols_*.asm`
## Available Symbol Files
| File | Contents | Address Range |
|------|----------|---------------|
| `symbols_wram.asm` | Work RAM labels | $7E0000-$7FFFFF |
| `symbols_sram.asm` | Save RAM labels | $700000-$70FFFF |
| `symbols_apu.asm` | Audio processor | APU addresses |
| `registers.asm` | Hardware registers | $2100-$21FF, $4200-$43FF |
## File Format
Simple assembly-style symbol definitions:
```asm
; Comment lines start with semicolon
SYMBOL_NAME = $AABBCC ; Optional inline comment
; Multi-line comments for documentation
; LENGTH: 0x10
BLOCK_START = $7E0000
```
## Symbol Naming Conventions
### Suffixes
| Suffix | Meaning |
|--------|---------|
| `L` | Low byte of 16-bit value |
| `H` | High byte of 16-bit value |
| `U` | Unused high byte |
| `Q` | Queue (for NMI updates) |
### Prefixes
| Prefix | Category |
|--------|----------|
| `LINK_` | Player state |
| `SPR_` | Sprite/enemy |
| `NMI_` | NMI handler |
| `OAM_` | OAM buffer |
| `UNUSED_` | Free RAM |
### Bitfield Documentation
```asm
; a - found to the north west
; b - found to the north east
; c - found to the south west
; d - found to the south east
; Bitfield: abcd....
TILE_DIRECTION = $7E000A
```
## Key Symbols (Quick Reference)
### Game State ($7E0010-$7E001F)
```asm
MODE = $7E0010 ; Main game mode
SUBMODE = $7E0011 ; Sub-mode within mode
LAG = $7E0012 ; NMI sync flag
INIDISPQ = $7E0013 ; Display brightness queue
NMISTRIPES = $7E0014 ; Tilemap update flag
NMICGRAM = $7E0015 ; Palette update flag
```
### Player Position (typical)
```asm
LINK_X_LO = $7E0022 ; Link X position (low)
LINK_X_HI = $7E0023 ; Link X position (high)
LINK_Y_LO = $7E0020 ; Link Y position (low)
LINK_Y_HI = $7E0021 ; Link Y position (high)
LINK_LAYER = $7E00EE ; Current layer (0=BG1, 1=BG2)
```
### Room/Dungeon
```asm
ROOM_ID = $7E00A0 ; Current room number
DUNGEON_ID = $7E040C ; Current dungeon
```
## C++ Parser
```cpp
#include <string>
#include <unordered_map>
#include <fstream>
#include <sstream>
#include <regex>
struct Symbol {
std::string name;
uint32_t address;
std::string comment;
};
std::unordered_map<uint32_t, Symbol> parse_symbols(const std::string& path) {
std::unordered_map<uint32_t, Symbol> symbols;
std::ifstream file(path);
std::string line;
// Pattern: NAME = $ADDRESS ; comment
std::regex pattern(R"(^(\w+)\s*=\s*\$([0-9A-Fa-f]+)\s*(?:;\s*(.*))?$)");
while (std::getline(file, line)) {
// Skip pure comment lines
if (line.empty() || line[0] == ';') continue;
std::smatch match;
if (std::regex_search(line, match, pattern)) {
Symbol sym;
sym.name = match[1].str();
sym.address = std::stoul(match[2].str(), nullptr, 16);
sym.comment = match[3].str();
symbols[sym.address] = sym;
}
}
return symbols;
}
// Get symbol name for address (returns empty if not found)
std::string lookup_symbol(const std::unordered_map<uint32_t, Symbol>& syms,
uint32_t addr) {
auto it = syms.find(addr);
return (it != syms.end()) ? it->second.name : "";
}
```
## Integration Ideas
### Hex Editor Enhancement
```cpp
// Display symbol alongside address
void draw_hex_line(uint32_t addr, const uint8_t* data) {
std::string sym = lookup_symbol(symbols, addr);
if (!sym.empty()) {
printf("%06X %-20s ", addr, sym.c_str());
} else {
printf("%06X %-20s ", addr, "");
}
// ... draw hex bytes
}
```
### Disassembly View
```cpp
// Replace addresses with symbols in ASM output
std::string format_operand(uint32_t addr) {
std::string sym = lookup_symbol(symbols, addr);
if (!sym.empty()) {
return sym;
}
return "$" + to_hex(addr);
}
```
### Memory Watcher
```cpp
struct Watch {
std::string label;
uint32_t address;
uint8_t size; // 1, 2, or 3 bytes
};
// Auto-populate watches from symbol file
std::vector<Watch> create_watches_from_symbols() {
std::vector<Watch> watches;
// Key game state
watches.push_back({"Mode", 0x7E0010, 1});
watches.push_back({"Submode", 0x7E0011, 1});
watches.push_back({"Link X", 0x7E0022, 2});
watches.push_back({"Link Y", 0x7E0020, 2});
watches.push_back({"Room", 0x7E00A0, 2});
return watches;
}
```
## Free RAM Discovery
Symbol files mark unused RAM:
```asm
; FREE RAM: 0x20
UNUSED_7E0500 = $7E0500
UNUSED_7E0501 = $7E0501
; ...
; BIG FREE RAM
UNUSED_7E1000 = $7E1000 ; Large block available
```
Parse for `FREE RAM` comments to find available space for ROM hacks.
## File Locations
```
~/Code/alttp-gigaleak/DISASM/jpdasm/
├── symbols_wram.asm # Work RAM ($7E)
├── symbols_sram.asm # Save RAM ($70)
├── symbols_apu.asm # Audio
├── registers.asm # Hardware registers
└── registers_spc.asm # SPC700 registers
```