573in1/schema/rominfo.json

{
	"$schema": "http://json-schema.org/draft-07/schema#",
	"$id":     "schema/rominfo.json",

	"title": "Flash or RTC RAM game header description",
	"type":  "object",

	"additionalProperties": false,

	"properties": {
		"signatureField": {
			"title":       "Signature field",
			"description": "The first 4 bytes of the game's static signature. Must be specified as 4 hexadecimal values separated by dashes. Only valid if the signature type is set to `static`.",
			"type":        "string",

			"pattern": "^([0-9a-f]{2}-){3}[0-9a-f]{2}$",
			"default": "20-00"
		},
		"yearField": {
			"title":       "Year field",
			"description": "The value of the 2-byte year field stored in the header. Usually either zero or the year the game came out encoded as BCD. Must be specified as 2 hexadecimal values separated by a dash.",
			"type":        "string",

			"pattern": "^[0-9a-f]{2}-[0-9a-f]{2}$",
			"default": "20-00"
		},

		"headerFlags": {
			"title": "Game header properties",
			"type":  "object",

			"additionalProperties": false,

			"properties": {
				"format": {
					"title":       "Header data format",
					"description": "Which of the currently known layouts the header's data is arranged in. Must be one of the following:\n- `regionOnly` (used only by early cartridges)\n- `basic` (used only by early cartridges)\n- `earlyExtended`\n- `extended`",
					"type":        "string",

					"enum": [
						"regionOnly",
						"basic",
						"earlyExtended",
						"extended"
					]
				},
				"specType": {
					"title":       "Specification code type",
					"description": "Whether and how the game's specification code is stored in the header. Must be one of the following:\n- `actual` (the full code is stored - GC, GE, etc.)\n- `wildcard` (the second character is replaced with an asterisk - G*)\nOmit if no specification is present in the header.",
					"type":        "string",

					"enum": [
						"actual",
						"wildcard"
					]
				},

				"scrambled": {
					"title":       "Scramble header data",
					"description": "Whether to scramble the header by interpreting it as a series of 16-bit big endian words and converting them to 32-bit little endian. This algorithm is used by some early games to scramble all data in RTC RAM.",
					"type":        "boolean"
				},
				"usesPublicArea": {
					"title":       "Header in public data area",
					"description": "Whether the header, along with any public IDs, is stored in the chip-specific unprivileged section of the cartridge's EEPROM (readable without the game's data key) rather than in the private area.",
					"type":        "boolean"
				},
				"lowercaseRegion": {
					"title":       "Force lowercase region code",
					"description": "Whether to store the region/version code in lowercase. Lowercase regions are used by some installation cartridges.",
					"type":        "boolean"
				}
			}
		},
		"checksumFlags": {
			"title": "Game header checksum properties",
			"type":  "object",

			"additionalProperties": false,

			"properties": {
				"width": {
					"title":       "Checksum width and type",
					"description": "Bit width of each input item and the resulting checksum value. Must be one of the following:\n- `byte` (interpret data as bytes, output an 8-bit sum)\n- `byteInWordOut` (interpret data as bytes, output a 16-bit sum)\n- `word` (interpret data as 16-bit words, output a 16-bit sum)",
					"type":        "string",

					"enum": [
						"byte",
						"byteInWordOut",
						"word"
					]
				},

				"bigEndianInput": {
					"title":       "Interpret input words as big endian",
					"description": "If true, each input word will be byte-swapped prior to computing the checksum. Only valid if the checksum width is set to `word`.",
					"type":        "boolean"
				},
				"bigEndianOutput": {
					"title":       "Store checksum in big endian format",
					"description": "If true, the checksum will be byte-swapped before being written into the header. Only valid if the checksum width is set to `byteInWordOut` or `word`.",
					"type":        "boolean"
				},
				"inverted": {
					"title":       "Invert header checksum",
					"description": "If true, all bits of the checksum will be negated before writing it into the header.",
					"type":        "boolean"
				},
				"forceGXSpec": {
					"title":       "Force GX specification when computing checksum",
					"description": "If true, the header's specification code will be temporarily overridden and set to GX while the checksum is calculated. Required by Dark Horse Legend, which mistakenly sets the specification to GE.",
					"type":        "boolean"
				}
			}
		},
		"signatureFlags": {
			"title": "Installation signature properties",
			"type":  "object",

			"additionalProperties": false,

			"properties": {
				"type": {
					"title":       "Installation signature type",
					"description": "Method used to generate the installation signature stored in the header. Must be one of the following:\n- `static` (fixed value identical across all installations of the game)\n- `checksum` (4-byte hash derived from the I/O board's ID)\n- `md5` (MD5 hash derived from the I/O board's ID)\nOmit if no signature is present.",
					"type":        "string",

					"enum": [
						"static",
						"checksum",
						"md5"
					]
				},

				"padWithFF": {
					"title":       "Pad signature area with 0xff bytes",
					"description": "Whether to fill unused space in the signature area with 0xff bytes instead of 0x00.",
					"type":        "boolean"
				}
			}
		}
	}
}