During factory setup, the Switch goes through calibration and the generated data from this process is written to two NAND user partitions (PRODINFO and PRODINFOF).

PRODINFOF is a FAT12 compliant filesystem and it's structure can be found here. It's mainly used to keep calibration logs and other assorted files.

PRODINFO is a raw binary blob containing the main calibration data, which ranges from hardware IDs to system keys.

CAL0

This is the raw data stored under the PRODINFO partition.

Offset	Size	Field	Description
0x0000	0x04	magic	"CAL0" header magic.
0x0004	0x04	version	Always 0x07.
0x0008	0x04	calib_data_size	Total size of calibration data minus 0x40 bytes (header + calib_data_sha256).
0x000C	0x02	model	Always 0x01.
0x000E	0x02	revision	Increases each time calibration data is installed.
0x0020	0x20	calib_data_sha256	SHA256 hash calculated over calibration data.
0x0040	0x1D	config_id1	Configuration ID string.
0x0060	0x20	reserved	Empty.
0x0080	0x04	wlan_country_codes_num	Number of elements in the wlan_country_codes array.
0x0084	0x04	wlan_country_codes_last_idx	Index of the last element in the wlan_country_codes array.
0x0088	0x180	wlan_country_codes	Array of WLAN country code strings. Each element is 3 bytes (code + NULL terminator).
0x0210	0x06	wlan_mac_addr
0x0220	0x06	bd_addr
0x0230	0x06	accelerometer_offset
0x0238	0x06	accelerometer_scale
0x0240	0x06	gyroscope_offset
0x0248	0x06	gyroscope_scale
0x0250	0x18	serial_number
0x0270	0x30	device_key_ecc_p256	Device key (ECC-P256 version; empty and unused).
0x02B0	0x180	device_cert_ecc_p256	Device certificate (ECC-P256 version; empty and unused).
0x0440	0x30	device_key_ecc_b233	Device key (ECC-B233 version; empty and unused).
0x0480	0x180	device_cert_ecc_b233	Device certificate (ECC-B233 version; active).
0x0610	0x30	eticket_key_ecc_p256	ETicket key (ECC-P256 version; empty and unused).
0x0650	0x180	eticket_cert_ecc_p256	ETicket certificate (ECC-P256 version; empty and unused).
0x07E0	0x30	eticket_key_ecc_b233	ETicket key (ECC-B233 version; empty and unused).
0x0820	0x180	eticket_cert_ecc_b233	ETicket certificate (ECC-B233 version; empty and unused).
0x09B0	0x110	ssl_key	SSL key (empty and unused).
0x0AD0	0x04	ssl_cert_size	Total size of the SSL certificate.
0x0AE0	0x800	ssl_cert	SSL certificate. Only ssl_cert_size bytes are used.
0x12E0	0x20	ssl_cert_sha256	SHA256 over the SSL certificate.
0x1300	0x1000	random_number	Random generated data.
0x2300	0x20	random_number_sha256	SHA256 over the random data block.
0x2320	0x110	gamecard_key	GameCard key (empty and unused).
0x2440	0x400	gamecard_cert	GameCard certificate.
0x2840	0x20	gamecard_cert_sha256	SHA256 over the GameCard certificate.
0x2860	0x220	eticket_key_rsa	ETicket key (RSA-2048 version; empty and unused).
0x2A90	0x240	eticket_cert_rsa	ETicket certificate (RSA-2048 version; active).
0x2CE0	0x18	battery_lot	Battery lot string ID.
0x2D00	0x800	speaker_calib_value	Speaker calibration values. Only 0x5A bytes are used.
0x3510	0x04	region_code
0x3520	0x50	amiibo_key	Amiibo key (ECQV and ECDSA versions).
0x3580	0x14	amiibo_cert_ecqv	Amiibo certificate (ECQV version).
0x35A0	0x70	amiibo_cert_ecdsa	Amiibo certificate (ECDSA version).
0x3620	0x40	amiibo_key_ecqv_bls	Amiibo key (ECQV-BLS version).
0x3670	0x20	amiibo_cert_ecqv_bls	Amiibo certificate (ECQV-BLS version).
0x36A0	0x90	amiibo_root_cert_ecqv_bls	Amiibo root certificate (ECQV-BLS version).
0x3740	0x04	product_model	1 = Nx, 2 = Copper
0x3750	0x06	color_variation
0x3760	0x0C	lcd_backlight_brightness_mapping
0x3770	0x50	device_ext_key_ecc_b233	Extended device key (ECC-B233 version; active).
0x37D0	0x50	eticket_ext_key_ecc_p256	Extended ETicket key (ECC-P256 version; empty and unused).
0x3830	0x50	eticket_ext_key_ecc_b233	Extended ETicket key (ECC-B233 version; empty and unused).
0x3890	0x240	eticket_ext_key_rsa	Extended ETicket key (RSA-2048 version; active).
0x3AE0	0x130	ssl_ext_key	Extended SSL key (active).
0x3C20	0x130	gamecard_ext_key	Extended GameCard key (active).
0x3D60	0x04	lcd_vendor_id
0x3D70	0x240	[5.0.0+] device_cert_rsa	Device certificate (RSA-2048 version).
0x3FC0	0x240	[5.0.0+] device_ext_key_rsa	Extended device key (RSA-2048 version).
0x4210	0x04	[5.0.0+] usb_type_c_power_source_circuit_version
0x4310	0x04	[6.0.0+] battery_version

Error detection

Each block of raw calibration data (with the exception of blocks with SHA256 hashes) is padded to 16 bytes, being the last 2 bytes a CRC-16 over said block.

XX XX XX XX XX XX XX XX XX XX XX XX XX XX XX XX
00 00 00 00 00 00 00 00 00 00 00 00 00 00 YY YY

XX == data
00 == padding
YY == crc

The CRC-16 is generated as follows:

unsigned int crc_16_table[16] = {
 0x0000, 0xCC01, 0xD801, 0x1400, 0xF001, 0x3C00, 0x2800, 0xE401,
 0xA001, 0x6C00, 0x7800, 0xB401, 0x5000, 0x9C01, 0x8801, 0x4400 };

unsigned short int get_crc_16 (char *p, int n) {
 unsigned short int crc = 0x55AA;
 int r;

 while (n-- > 0) {
   r = crc_16_table[crc & 0xF];
   crc = (crc >> 4) & 0x0FFF;
   crc = crc ^ r ^ crc_16_table[*p & 0xF];

   r = crc_16_table[crc & 0xF];
   crc = (crc >> 4) & 0x0FFF;
   crc = crc ^ r ^ crc_16_table[(*p >> 4) & 0xF];

   p++;
 }

 return(crc);
}

Calibration

CAL0

Error detection