A copy of the RESTART_BLOCK structure in the NVRAM header will be placed in the caller's buffer.
#include <sys/mdio.h>
  int md_restart_block_read (md)
                struct mdio *md;
| Item | Description | 
|---|---|
| md |   Specifies the address of the mdio structure. The mdio structure
contains the following fields:  
  | 
The RestartBlock which is in the NVRAM header will be copied to the user supplied buffer. This block is a communication vehicle for the software and the firmware.
Returns 0 for successful completion.
| Item | Description | 
|---|---|
| ENOMEM | Indicates that there was not enough room in the user supplied buffer to contain the RestartBlock. | 
| EINVAL | Indicates this is not a PowerPC® reference platform. | 
Kernel Extensions and Device Driver Management Kernel Services in Kernel Extensions and Device Support Programming Concepts.