compatible format . Ventoy

Ventoy Information Format

Ventoy information is 512 bytes long and in the format as follows: (structure packed with 1 byte, integers are in little-endian)

    
             Offset 
             Len 
             Type 
             Name 
             Description 
        
             0  16  UUID   Signature UUID 
             Signature for this information, the hex value is 20207777772e76656e746f792e6e6574 
        
             16  1  UINT8   Check Sum 
             This value, when added to all other 511 bytes, results in the value 00h (using 8-bit addition calculations). 
        
  17  16  UUID   Disk GUID 
            
                GUID to uniquely identify the disk. 

                Note: This GUID differs from the one used in GPT disks. It is a 16-byte UUID written by Ventoy during partition creation. The data starts at offset 384 within the first 512-byte sector of the USB drive. This value is written consistently for both MBR and GPT partition schemes. It can serve as an alternative to Disk Signature for precise disk identification.
            
  33  8  UINT64   Disk Size 
             The disk size in bytes. 

                Note: This size is obtained during the GRUB stage. It may differ from the value retrieved after system boot, so it is not recommended for strict verification.
             
             41  2  UINT16   Disk Partition ID 
             The partition ID (begin with 1) which hold the iso file 
        
             43  2  UINT16   Partition Filesytem 
             The partition filesystem 
 0:exfat   1:ntfs   2:ext   3:xfs   4:udf   5:fat    other:reserved 
        
             45  384  STRING   ISO File Path 
             The full iso file path under the partition, ( begin with '/' ) (UTF-8 encode)
        
  429  8  UINT64   ISO File Size 
             The iso file size in bytes 
        
             437  8  UINT64   ISO location info address 
             The phy memory address which contains iso file location information 
        
  445  4  UINT32   ISO location info length 
             The iso file location information length
        
  449  32  BYTES   Ventoy Reserved 
             Reserved by Ventoy
        
  481  4  BYTES   Disk Signature 
            
                Disk signature to uniquely identify the disk. 

                4-byte data starting at offset 440 of the first 512-byte sector on the USB drive.

  485  27  BYTES   Reserved 
             Reserved for future

Offset	Len	Type	Name	Description
0	16	UUID	Signature UUID	Signature for this information, the hex value is `20207777772e76656e746f792e6e6574`
16	1	UINT8	Check Sum	This value, when added to all other 511 bytes, results in the value 00h (using 8-bit addition calculations).
17	16	UUID	Disk GUID	GUID to uniquely identify the disk. Note: This GUID differs from the one used in GPT disks. It is a 16-byte UUID written by Ventoy during partition creation. The data starts at offset 384 within the first 512-byte sector of the USB drive. This value is written consistently for both MBR and GPT partition schemes. It can serve as an alternative to Disk Signature for precise disk identification.
33	8	UINT64	Disk Size	The disk size in bytes. Note: This size is obtained during the GRUB stage. It may differ from the value retrieved after system boot, so it is not recommended for strict verification.
41	2	UINT16	Disk Partition ID	The partition ID (begin with 1) which hold the iso file
43	2	UINT16	Partition Filesytem	The partition filesystem 0:exfat 1:ntfs 2:ext 3:xfs 4:udf 5:fat other:reserved
45	384	STRING	ISO File Path	The full iso file path under the partition, ( begin with '/' ) (UTF-8 encode)
429	8	UINT64	ISO File Size	The iso file size in bytes
437	8	UINT64	ISO location info address	The phy memory address which contains iso file location information
445	4	UINT32	ISO location info length	The iso file location information length
449	32	BYTES	Ventoy Reserved	Reserved by Ventoy
481	4	BYTES	Disk Signature	Disk signature to uniquely identify the disk. 4-byte data starting at offset 440 of the first 512-byte sector on the USB drive.
485	27	BYTES	Reserved	Reserved for future

You can refer to struct ventoy_os_param defined in Ventoy's source code (ventoy.h).