readme.eeprom

linux for amd development lx8

This details the interface for the /dev/eeprom device exposed by the
geodeaes module.

/dev/eeprom (char 10,157) is a full featured read/write device.  Up to
232 bytes of storage may be available to the user.  To read or write from
the eeprom standard storage, use it like you would any other device file.

For example:
	fd = open("/dev/eeprom", O_RDWR);
	lseek(fd, 0, SEEK_SET);
	write(fd, "Hello EEPROM!", 13);
	lseek(fd, 128, SEEK_SET);
	read(fd, buffer, sizeof(buffer));
	printf("The eeprom says: %s\n", buffer);
	close(fd);

In addition, the EEPROM has a hidden key storage and permissions
that can be set or read via ioctl() calls:

EIOSKEYOFF - Disable the usage of the hardware key till reboot
EIOSLOKUP  - Lock the upper range of bytes (96-232) (this is permanent!)
EIOSLOKLW  - Lock the lower range of bytes (0 - 96) and the key storage
	     this is permanent
EIOSKEY	   - Set the key in the hidden storage
EIOGPERMS  - Query the permissions on the sections