diff options
| -rw-r--r-- | src/include/memory_info.h | 55 |
1 files changed, 52 insertions, 3 deletions
diff --git a/src/include/memory_info.h b/src/include/memory_info.h index a1b3553a77..4613015d75 100644 --- a/src/include/memory_info.h +++ b/src/include/memory_info.h @@ -23,24 +23,73 @@ #define DIMM_INFO_PART_NUMBER_SIZE 19 #define DIMM_INFO_TOTAL 8 /* Maximum num of dimm is 8 */ -/* +/** * If this table is filled and put in CBMEM, * then these info in CBMEM will be used to generate smbios type 17 table + * + * Values are specified according to the JEDEC SPD Standard. */ struct dimm_info { + /* + * Size of the module in MiB. + */ uint32_t dimm_size; + /* + * SMBIOS (not SPD) device type. + * + * See the smbios.h smbios_memory_device_type enum. + */ uint16_t ddr_type; uint16_t ddr_frequency; uint8_t rank_per_dimm; uint8_t channel_num; uint8_t dimm_num; uint8_t bank_locator; - /* The last byte is '\0' for the end of string */ + /* + * The last byte is '\0' for the end of string. + * + * Even though the SPD spec defines this field as a byte array the value + * is passed directly to SMBIOS as a string, and thus must be printable + * ASCII. + */ uint8_t serial[DIMM_INFO_SERIAL_SIZE]; - /* The last byte is '\0' for the end of string */ + /* + * The last byte is '\0' for the end of string + * + * Must contain only printable ASCII. + */ uint8_t module_part_number[DIMM_INFO_PART_NUMBER_SIZE]; + /* + * SPD Manufacturer ID + */ uint16_t mod_id; + /* + * SPD Module Type. + * + * See spd.h for valid values. + * + * e.g., SPD_RDIMM, SPD_SODIMM, SPD_MICRO_DIMM + */ uint8_t mod_type; + /* + * SPD bus width. + * + * Bits 0 - 2 encode the primary bus width: + * 0b000 = 8 bit width + * 0b001 = 16 bit width + * 0b010 = 32 bit width + * 0b011 = 64 bit width + * + * Bits 3 - 4 encode the extension bits (ECC): + * 0b00 = 0 extension bits + * 0b01 = 8 bit of ECC + * + * e.g., + * 64 bit bus with 8 bits of ECC (72 bits total): 0b1011 + * 64 bit bus with 0 bits of ECC (64 bits total): 0b0011 + * + * See the smbios.h smbios_memory_bus_width enum. + */ uint8_t bus_width; } __packed; |