1 /* Memory information */
2 /* SPDX-License-Identifier: GPL-2.0-only */
4 #ifndef _MEMORY_INFO_H_
5 #define _MEMORY_INFO_H_
9 #define DIMM_INFO_SERIAL_SIZE 4
10 #define DIMM_INFO_PART_NUMBER_SIZE 33
11 #define DIMM_INFO_TOTAL 32
14 * If this table is filled and put in CBMEM,
15 * then these info in CBMEM will be used to generate smbios type 17 table
17 * Values are specified according to the JEDEC SPD Standard.
21 * Size of the module in MiB.
25 * SMBIOS (not SPD) device type.
27 * See the smbios.h smbios_memory_type enum.
31 * ddr_frequency is deprecated.
32 * Use max_speed_mts and configured_speed_mts instead.
34 uint16_t ddr_frequency
;
35 uint8_t rank_per_dimm
;
42 uint8_t serial
[DIMM_INFO_SERIAL_SIZE
];
44 * The last byte is '\0' for the end of string
46 * Must contain only printable ASCII.
48 uint8_t module_part_number
[DIMM_INFO_PART_NUMBER_SIZE
];
56 * See spd.h for valid values.
58 * e.g., SPD_RDIMM, SPD_SODIMM, SPD_MICRO_DIMM
64 * Bits 0 - 2 encode the primary bus width:
66 * 0b001 = 16 bit width
67 * 0b010 = 32 bit width
68 * 0b011 = 64 bit width
70 * Bits 3 - 4 encode the extension bits (ECC):
71 * 0b00 = 0 extension bits
75 * 64 bit bus with 8 bits of ECC (72 bits total): 0b1011
76 * 64 bit bus with 0 bits of ECC (64 bits total): 0b0011
78 * See the smbios.h smbios_memory_bus_width enum.
87 * If the value is 0, ddr_frequency should be used instead.
89 uint16_t max_speed_mts
;
91 * Configured speed in MT/s
92 * If the value is 0, ddr_frequency should be used instead.
94 uint16_t configured_speed_mts
;
99 * SMBIOS error correction type.
100 * See the smbios.h smbios_memory_array_ecc enum.
103 /* Maximum capacity the DRAM controller/mainboard supports */
104 uint32_t max_capacity_mib
;
105 /* Maximum number of DIMMs the DRAM controller/mainboard supports */
106 uint16_t number_of_devices
;
108 /* active DIMM configuration */
110 struct dimm_info dimm
[DIMM_INFO_TOTAL
];
114 * mainboard_get_dram_part_num returns a DRAM part number override string
115 * return NULL = no part number override provided by mainboard
116 * return non-NULL = pointer to a string terminating in '\0'
118 const char *mainboard_get_dram_part_num(void);