blob: 527c44d5fca429e0df38b7df34daf52abef167bb [file] [log] [blame]
#include <stdint.h>
/* The linuxbios table information is for conveying information
* from the firmware to the loaded OS image. Primarily this
* is expected to be information that cannot be discovered by
* other means, such as quering the hardware directly.
* All of the information should be Position Independent Data.
* That is it should be safe to relocated any of the information
* without it's meaning/correctnes changing. For table that
* can reasonably be used on multiple architectures the data
* size should be fixed. This should ease the transition between
* 32 bit and 64 bit architectures etc.
* The completeness test for the information in this table is:
* - Can all of the hardware be detected?
* - Are the per motherboard constants available?
* - Is there enough to allow a kernel to run that was written before
* a particular motherboard is constructed? (Assuming the kernel
* has drivers for all of the hardware but it does not have
* assumptions on how the hardware is connected together).
* With this test it should be straight forward to determine if a
* table entry is required or not. This should remove much of the
* long term compatibility burden as table entries which are
* irrelevant or have been replaced by better alternatives may be
* dropped. Of course it is polite and expidite to include extra
* table entries and be backwards compatible, but it is not required.
/* Since LinuxBIOS is usually compiled 32bit, gcc will align 64bit
* types to 32bit boundaries. If the LinuxBIOS table is dumped on a
* 64bit system, a uint64_t would be aligned to 64bit boundaries,
* breaking the table format.
* lb_uint64 will keep 64bit LinuxBIOS table values aligned to 32bit
* to ensure compatibility. They can be accessed with the two functions
* below: unpack_lb64() and pack_lb64()
* See also: util/lbtdump/lbtdump.c
struct lb_uint64 {
uint32_t lo;
uint32_t hi;
static inline uint64_t unpack_lb64(struct lb_uint64 value)
uint64_t result;
result = value.hi;
result = (result << 32) + value.lo;
return result;
static inline struct lb_uint64 pack_lb64(uint64_t value)
struct lb_uint64 result;
result.lo = (value >> 0) & 0xffffffff;
result.hi = (value >> 32) & 0xffffffff;
return result;
struct lb_header
uint8_t signature[4]; /* LBIO */
uint32_t header_bytes;
uint32_t header_checksum;
uint32_t table_bytes;
uint32_t table_checksum;
uint32_t table_entries;
/* Every entry in the boot enviroment list will correspond to a boot
* info record. Encoding both type and size. The type is obviously
* so you can tell what it is. The size allows you to skip that
* boot enviroment record if you don't know what it easy. This allows
* forward compatibility with records not yet defined.
struct lb_record {
uint32_t tag; /* tag ID */
uint32_t size; /* size of record (in bytes) */
#define LB_TAG_UNUSED 0x0000
#define LB_TAG_MEMORY 0x0001
struct lb_memory_range {
struct lb_uint64 start;
struct lb_uint64 size;
uint32_t type;
#define LB_MEM_RAM 1 /* Memory anyone can use */
#define LB_MEM_RESERVED 2 /* Don't use this memory region */
#define LB_MEM_TABLE 16 /* Ram configuration tables are kept in */
struct lb_memory {
uint32_t tag;
uint32_t size;
struct lb_memory_range map[0];
#define LB_TAG_HWRPB 0x0002
struct lb_hwrpb {
uint32_t tag;
uint32_t size;
uint64_t hwrpb;
#define LB_TAG_MAINBOARD 0x0003
struct lb_mainboard {
uint32_t tag;
uint32_t size;
uint8_t vendor_idx;
uint8_t part_number_idx;
uint8_t strings[0];
#define LB_TAG_VERSION 0x0004
#define LB_TAG_EXTRA_VERSION 0x0005
#define LB_TAG_BUILD 0x0006
#define LB_TAG_COMPILE_TIME 0x0007
#define LB_TAG_COMPILE_BY 0x0008
#define LB_TAG_COMPILE_HOST 0x0009
#define LB_TAG_COMPILE_DOMAIN 0x000a
#define LB_TAG_COMPILER 0x000b
#define LB_TAG_LINKER 0x000c
#define LB_TAG_ASSEMBLER 0x000d
struct lb_string {
uint32_t tag;
uint32_t size;
uint8_t string[0];
/* The following structures are for the cmos definitions table */
/* cmos header record */
struct cmos_option_table {
uint32_t tag; /* CMOS definitions table type */
uint32_t size; /* size of the entire table */
uint32_t header_length; /* length of header */
/* cmos entry record
This record is variable length. The name field may be
shorter than CMOS_MAX_NAME_LENGTH. The entry may start
anywhere in the byte, but can not span bytes unless it
starts at the beginning of the byte and the length is
fills complete bytes.
#define LB_TAG_OPTION 201
struct cmos_entries {
uint32_t tag; /* entry type */
uint32_t size; /* length of this record */
uint32_t bit; /* starting bit from start of image */
uint32_t length; /* length of field in bits */
uint32_t config; /* e=enumeration, h=hex, r=reserved */
uint32_t config_id; /* a number linking to an enumeration record */
uint8_t name[CMOS_MAX_NAME_LENGTH]; /* name of entry in ascii,
variable length int aligned */
/* cmos enumerations record
This record is variable length. The text field may be
shorter than CMOS_MAX_TEXT_LENGTH.
#define LB_TAG_OPTION_ENUM 202
struct cmos_enums {
uint32_t tag; /* enumeration type */
uint32_t size; /* length of this record */
uint32_t config_id; /* a number identifying the config id */
uint32_t value; /* the value associated with the text */
uint8_t text[CMOS_MAX_TEXT_LENGTH]; /* enum description in ascii,
variable length int aligned */
/* cmos defaults record
This record contains default settings for the cmos ram.
struct cmos_defaults {
uint32_t tag; /* default type */
uint32_t size; /* length of this record */
uint32_t name_length; /* length of the following name field */
uint8_t name[CMOS_MAX_NAME_LENGTH]; /* name identifying the default */
uint8_t default_set[CMOS_IMAGE_BUFFER_SIZE]; /* default settings */
struct cmos_checksum {
uint32_t tag;
uint32_t size;
/* In practice everything is byte aligned, but things are measured
* in bits to be consistent.
uint32_t range_start; /* First bit that is checksummed (byte aligned) */
uint32_t range_end; /* Last bit that is checksummed (byte aligned) */
uint32_t location; /* First bit of the checksum (byte aligned) */
uint32_t type; /* Checksum algorithm that is used */