The info member

When the IPL code detects system features (e.g., amount of memory installed, current time, information about the bus used on the system, etc.), it stores this information in the info array so that the startup code can retrieve it later. This design saves the startup code from repeating the same detection logic as the IPL. The startup_info* structures and enumerated types include:

startup_info_hdr, startup_info_types, startup_info_skip, startup_info_mem and startup_info_mem_extended, startup_info_disk, startup_info_time, startup_info_box, bootargs_entry, startup_trailer

startup_info_hdr

The startup_header info member is declared as an array of longs. This declaration allocates a storage area, which contains a set of structures, each beginning with a startup_info_hdr header:

struct startup_info_hdr {
	_Uint16t			type;
	_Uint16t			size;
};

startup_info_types

enum startup_info_types {
    STARTUP_INFO_SKIP = 0,	/* If size 0 then end of list */
    STARTUP_INFO_MEM,
    STARTUP_INFO_DISK,
    STARTUP_INFO_TIME,
    STARTUP_INFO_BOX,
    STARTUP_INFO_USER = 0x8000	/* User reserved numbers start here */
};

The startup_info_hdr enumerated types include:

STARTUP_INFO_SKIP

Ignore this field. If the corresponding size member is 0, this is the end of the info list.

STARTUP_INFO_MEM

A startup_info_mem or startup_info_mem_extended structure is present.

STARTUP_INFO_DISK

A startup_info_disk structure is present.

STARTUP_INFO_TIME

A startup_info_time structure is present.

STARTUP_INFO_BOX

A startup_info_box structure is present.

startup_info_skip

struct startup_info_skip {
    struct startup_info_hdr	hdr;
};

startup_info_mem and startup_info_mem_extended

These structures contain an address and size pair defining a chunk of memory that should be added to procnto's free memory pool.

The startup_info_mem structure is defined as follows:

struct startup_info_mem {
	struct startup_info_hdr	hdr;
	_Uint32t				addr;
	_Uint32t				size;
};

The addr and size fields are 32 bits long, so memory is limited to 4 GB. For larger memory blocks, the startup_info_mem_extended structure is used:

struct startup_info_mem_extended {
	struct startup_info_mem	mem;
	_Uint32t			addr_hi;
	_Uint32t			size_hi;
};

For the extended structure, determine the address and size from the addr_hi and size_hi members and the encapsulated startup_info_mem structure as follows:

((paddr64_t) addr_hi << 32) | mem.addr
((paddr64_t) size_hi << 32) | mem.size

startup_info_disk

The startup_info_disk structure contains information about any hard disks detected. It is defined as follows:

struct startup_info_disk {
	struct startup_info_hdr	hdr;
	_Uint8t					drive;
	_Uint8t					zero;
	_Uint16t				heads;
	_Uint16t				cylinders;
	_Uint16t				sectors;
	_Uint32t				blocks;
};

Contains information about any hard disks detected. Its members are as follows:

startup_info_time

The startup_info_time structure contains a record of the system's most recent startup time.

struct startup_info_time {
    struct startup_info_hdr    hdr;
    _Uint32t	               time;
};

startup_info_box

struct startup_info_box {
	struct startup_info_hdr	hdr;
	_Uint8t					boxtype;
	_Uint8t					bustype;
	_Uint8t					spare[2];
};

bootargs_entry

struct bootargs_entry {
	_Uint8t					size_lo;	/* Includes entire structure */
	_Uint8t					size_hi;
	_Int8t					argc;
	_Int8t					envc;
	_Uint32t				shdr_addr;
	char					args[1];	/* variable length */
};

startup_trailer

The startup_trailer structure contains a checksum for the startup_header structure, calculated from the start of the header to the start of the trailer (this structure):

struct startup_trailer {
    unsigned long           cksum;
};