FATB ("BTAF") - File Allocation Table

Author(s): Gonhex
Research: NOCASH

The file allocation table stores offsets to beginning and end of all entries within the file image.

Table of Contents

• Data Structure
  • Section Container
  • FATB Container
  • Entry Offset
• Specification
  • Files

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Data Structure

Section Container

struct ContainerSectionFATB
{
    /* 0x0 */ struct NitroSectionHeader sectionHeader;
    /* 0x8 */ struct ContainerFATB sectionData;
}; // entry size = sectionHeader.lengthSection

Field Name	Description	Data Type
sectionHeader	Header of this section. sectionHeader.signature = "BTAF".	NitroSectionHeader
sectionData	Content of this section.	ContainerFATB

FATB Container

struct ContainerFATB
{
    // header
    /* 0x0 */ uint16_t numberFiles;
    /* 0x2 */ uint16_t reserved;
    
    // data
    /* 0x4 */ EntryOffset dataEntries[numberFiles];
}; // entry size = sectionHeader.lengthSection - 0x8

Field Name	Description	Data Type
numberFiles	Number of files stored in this archive.	uint16_t
reserved	Always 0.	uint16_t
dataEntries	Contains offsets to all files managed by this archive.	EntryOffset[]

Entry Offset

struct EntryOffset
{
    /* 0x0 */ uint32_t offsetBeginning;
    /* 0x4 */ uint32_t offsetEnd;
}; // entry size = 0x8

Field Name	Description	Data Type
offsetBeginning	Offset to the file within the file image.	uint32_t
offsetEnd	Offset to the end of the file within the file image.	uint32_t

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Specification

Files

• Nitro Archive