Data Fields | |
struct { | |
UINT8 Header | |
UINT8 File | |
} | Checksum |
UINT16 | Checksum16 |
struct { ... } EFI_FFS_INTEGRITY_CHECK::Checksum |
This is the full 16 bits of the IntegrityCheck field.
If the FFS_ATTRIB_CHECKSUM (see definition below) bit of the Attributes field is set to one, the IntegrityCheck.Checksum.File field is an 8-bit checksum of the file data. If the FFS_ATTRIB_CHECKSUM bit of the Attributes field is cleared to zero, the IntegrityCheck.Checksum.File field must be initialized with a value of 0xAA. The IntegrityCheck.Checksum.File field is valid any time the EFI_FILE_DATA_VALID bit is set in the State field.
The IntegrityCheck.Checksum.Header field is an 8-bit checksum of the file header. The State and IntegrityCheck.Checksum.File fields are assumed to be zero and the checksum is calculated such that the entire header sums to zero.