---
title: readDiscStructure
framework: kernel
role: pseudoSymbol
path: kernel/iobdblockstoragedevice/1811564-readdiscstructure
---

# readDiscStructure

## Declaration

```occ
virtual IOReturn readDiscStructure(
 IOMemoryDescriptor *buffer, 
 UInt8format, 
 UInt32address, 
 UInt8layer, 
 UInt8grantID, 
 UInt8type ) = 0; 
```

## Parameters

- `buffer`: Buffer for the data transfer. The size of the buffer implies the size of the data transfer.
- `format`: As documented by MMC.
- `address`: As documented by MMC.
- `layer`: As documented by MMC.
- `grantID`: As documented by MMC.
- `type`: As documented by MMC.

## Return Value

Return Value Returns the status of the data transfer.

## Overview

Overview Issue an MMC READ DISC STRUCTURE command.

## See Also

### Miscellaneous

- [init](kernel/iobdblockstoragedevice/1811554-init.md)
- [splitTrack](kernel/iobdblockstoragedevice/1811575-splittrack.md)