diff mbox

[U-Boot,2/2] x86: Add SMBIOS table support

Message ID 1444385862-31141-2-git-send-email-bmeng.cn@gmail.com
State Superseded
Delegated to: Simon Glass
Headers show

Commit Message

Bin Meng Oct. 9, 2015, 10:17 a.m. UTC 
System Management BIOS (SMBIOS) is a specification for how
motherboard and system vendors present management information
about their products in a standard format by extending the BIOS
interface on Intel architecture systems. As of today the latest
spec is 3.0 and can be downloaded from DMTF website. This commit
adds a simple and minimum required implementation.

Signed-off-by: Bin Meng <bmeng.cn@gmail.com>
---

 arch/x86/Kconfig              |  11 ++
 arch/x86/include/asm/smbios.h | 181 +++++++++++++++++++++++++++++++
 arch/x86/lib/Makefile         |   1 +
 arch/x86/lib/smbios.c         | 242 ++++++++++++++++++++++++++++++++++++++++++
 arch/x86/lib/tables.c         |   5 +
 doc/README.x86                |   2 -
 6 files changed, 440 insertions(+), 2 deletions(-)
 create mode 100644 arch/x86/include/asm/smbios.h
 create mode 100644 arch/x86/lib/smbios.c

Comments

Simon Glass Oct. 9, 2015, 1:02 p.m. UTC | #1 
Hi Bin,

On 9 October 2015 at 11:17, Bin Meng <bmeng.cn@gmail.com> wrote:
> System Management BIOS (SMBIOS) is a specification for how
> motherboard and system vendors present management information
> about their products in a standard format by extending the BIOS
> interface on Intel architecture systems. As of today the latest
> spec is 3.0 and can be downloaded from DMTF website. This commit
> adds a simple and minimum required implementation.
>
> Signed-off-by: Bin Meng <bmeng.cn@gmail.com>
> ---
>
>  arch/x86/Kconfig              |  11 ++
>  arch/x86/include/asm/smbios.h | 181 +++++++++++++++++++++++++++++++
>  arch/x86/lib/Makefile         |   1 +
>  arch/x86/lib/smbios.c         | 242 ++++++++++++++++++++++++++++++++++++++++++
>  arch/x86/lib/tables.c         |   5 +
>  doc/README.x86                |   2 -
>  6 files changed, 440 insertions(+), 2 deletions(-)
>  create mode 100644 arch/x86/include/asm/smbios.h
>  create mode 100644 arch/x86/lib/smbios.c

Looks good - just a few style requests.

>
> diff --git a/arch/x86/Kconfig b/arch/x86/Kconfig
> index 5e42d7d..bf09b21 100644
> --- a/arch/x86/Kconfig
> +++ b/arch/x86/Kconfig
> @@ -358,6 +358,17 @@ config GENERATE_ACPI_TABLE
>           by the operating system. It defines platform-independent interfaces
>           for configuration and power management monitoring.
>
> +config GENERATE_SMBIOS_TABLE
> +       bool "Generate an SMBIOS (System Management BIOS) table"
> +       default y
> +       help
> +         The System Management BIOS (SMBIOS) specification addresses how
> +         motherboard and system vendors present management information about
> +         their products in a standard format by extending the BIOS interface
> +         on Intel architecture systems.
> +
> +         Check http://www.dmtf.org/standards/smbios for details.
> +
>  endmenu
>
>  config MAX_PIRQ_LINKS
> diff --git a/arch/x86/include/asm/smbios.h b/arch/x86/include/asm/smbios.h
> new file mode 100644
> index 0000000..1fa7d74
> --- /dev/null
> +++ b/arch/x86/include/asm/smbios.h
> @@ -0,0 +1,181 @@
> +/*
> + * Copyright (C) 2015, Bin Meng <bmeng.cn@gmail.com>
> + *
> + * Adapted from coreboot src/include/smbios.h
> + *
> + * SPDX-License-Identifier:    GPL-2.0+
> + */
> +
> +#ifndef _SMBIOS_H_
> +#define _SMBIOS_H_
> +
> +/* SMBIOS spec version implemented */
> +#define SMBIOS_MAJOR_VER       3
> +#define SMBIOS_MINOR_VER       0
> +
> +/* SMBIOS structure types */
> +enum {
> +       SMBIOS_BIOS_INFORMATION = 0,
> +       SMBIOS_SYSTEM_INFORMATION = 1,
> +       SMBIOS_SYSTEM_ENCLOSURE = 3,
> +       SMBIOS_PROCESSOR_INFORMATION = 4,
> +       SMBIOS_CACHE_INFORMATION = 7,
> +       SMBIOS_SYSTEM_SLOTS = 9,
> +       SMBIOS_PHYS_MEMORY_ARRAY = 16,
> +       SMBIOS_MEMORY_DEVICE = 17,
> +       SMBIOS_MEMORY_ARRAY_MAPPED_ADDRESS = 19,
> +       SMBIOS_SYSTEM_BOOT_INFORMATION = 32,
> +       SMBIOS_END_OF_TABLE = 127
> +};
> +
> +#define SMBIOS_INTERMEDIATE_OFFSET     16
> +#define SMBIOS_STRUCT_EOS_BYTES                2
> +
> +struct __packed smbios_entry {
> +       u8 anchor[4];
> +       u8 checksum;
> +       u8 length;
> +       u8 major_ver;
> +       u8 minor_ver;
> +       u16 max_struct_size;
> +       u8 entry_point_rev;
> +       u8 formatted_area[5];
> +       u8 intermediate_anchor[5];
> +       u8 intermediate_checksum;
> +       u16 struct_table_length;
> +       u32 struct_table_address;
> +       u16 struct_count;
> +       u8 bcd_rev;
> +};
> +
> +/* BIOS characteristics */
> +#define BIOS_CHARACTERISTICS_PCI_SUPPORTED     (1 << 7)
> +#define BIOS_CHARACTERISTICS_UPGRADEABLE       (1 << 11)
> +#define BIOS_CHARACTERISTICS_SELECTABLE_BOOT   (1 << 16)
> +
> +#define BIOS_CHARACTERISTICS_EXT1_ACPI         (1 << 0)
> +#define BIOS_CHARACTERISTICS_EXT2_TARGET       (1 << 2)
> +
> +struct __packed smbios_type0 {
> +       u8 type;
> +       u8 length;
> +       u16 handle;
> +       u8 vendor;
> +       u8 bios_ver;
> +       u16 bios_start_segment;
> +       u8 bios_release_date;
> +       u8 bios_rom_size;
> +       u64 bios_characteristics;
> +       u8 bios_characteristics_ext1;
> +       u8 bios_characteristics_ext2;
> +       u8 bios_major_release;
> +       u8 bios_minor_release;
> +       u8 ec_major_release;
> +       u8 ec_minor_release;
> +       char eos[SMBIOS_STRUCT_EOS_BYTES];
> +};
> +
> +struct __packed smbios_type1 {
> +       u8 type;
> +       u8 length;
> +       u16 handle;
> +       u8 manufacturer;
> +       u8 product_name;
> +       u8 version;
> +       u8 serial_number;
> +       u8 uuid[16];
> +       u8 wakeup_type;
> +       u8 sku_number;
> +       u8 family;
> +       char eos[SMBIOS_STRUCT_EOS_BYTES];
> +};
> +
> +#define SMBIOS_ENCLOSURE_DESKTOP       3
> +#define SMBIOS_STATE_SAFE              3
> +#define SMBIOS_SECURITY_NONE           3
> +
> +struct __packed smbios_type3 {
> +       u8 type;
> +       u8 length;
> +       u16 handle;
> +       u8 manufacturer;
> +       u8 chassis_type;
> +       u8 version;
> +       u8 serial_number;
> +       u8 asset_tag_number;
> +       u8 bootup_state;
> +       u8 power_supply_state;
> +       u8 thermal_state;
> +       u8 security_status;
> +       u32 oem_defined;
> +       u8 height;
> +       u8 number_of_power_cords;
> +       u8 element_count;
> +       u8 element_record_length;
> +       char eos[SMBIOS_STRUCT_EOS_BYTES];
> +};
> +
> +#define SMBIOS_PROCESSOR_TYPE_CENTRAL  3
> +#define SMBIOS_PROCESSOR_STATUS_ENABLED        1
> +#define SMBIOS_PROCESSOR_UPGRADE_NONE  6
> +
> +struct __packed smbios_type4 {
> +       u8 type;
> +       u8 length;
> +       u16 handle;
> +       u8 socket_designation;
> +       u8 processor_type;
> +       u8 processor_family;
> +       u8 processor_manufacturer;
> +       u32 processor_id[2];
> +       u8 processor_version;
> +       u8 voltage;
> +       u16 external_clock;
> +       u16 max_speed;
> +       u16 current_speed;
> +       u8 status;
> +       u8 processor_upgrade;
> +       u16 l1_cache_handle;
> +       u16 l2_cache_handle;
> +       u16 l3_cache_handle;
> +       u8 serial_number;
> +       u8 asset_tag;
> +       u8 part_number;
> +       u8 core_count;
> +       u8 core_enabled;
> +       u8 thread_count;
> +       u16 processor_characteristics;
> +       u16 processor_family2;
> +       u16 core_count2;
> +       u16 core_enabled2;
> +       u16 thread_count2;
> +       char eos[SMBIOS_STRUCT_EOS_BYTES];
> +};
> +
> +struct __packed smbios_type32 {
> +       u8 type;
> +       u8 length;
> +       u16 handle;
> +       u8 reserved[6];
> +       u8 boot_status;
> +       u8 eos[SMBIOS_STRUCT_EOS_BYTES];
> +};
> +
> +struct __packed smbios_type127 {
> +       u8 type;
> +       u8 length;
> +       u16 handle;
> +       u8 eos[SMBIOS_STRUCT_EOS_BYTES];
> +};
> +
> +/**
> + * write_smbios_table() - Write SMBIOS table
> + *
> + * This writes SMBIOS table at a given address.
> + *
> + * @addr:      start address to write SMBIOS table
> + * @return:    end address of SMBIOS table
> + */
> +u32 write_smbios_table(u32 addr);
> +
> +#endif /* _SMBIOS_H_ */
> diff --git a/arch/x86/lib/Makefile b/arch/x86/lib/Makefile
> index 169062e..4ac9956 100644
> --- a/arch/x86/lib/Makefile
> +++ b/arch/x86/lib/Makefile
> @@ -30,6 +30,7 @@ obj-y += relocate.o
>  obj-y += physmem.o
>  obj-$(CONFIG_X86_RAMTEST) += ramtest.o
>  obj-y += sfi.o
> +obj-$(CONFIG_GENERATE_SMBIOS_TABLE) += smbios.o
>  obj-y  += string.o
>  obj-$(CONFIG_GENERATE_ACPI_TABLE) += acpi_table.o
>  obj-y  += tables.o
> diff --git a/arch/x86/lib/smbios.c b/arch/x86/lib/smbios.c
> new file mode 100644
> index 0000000..2cb2d0c
> --- /dev/null
> +++ b/arch/x86/lib/smbios.c
> @@ -0,0 +1,242 @@
> +/*
> + * Copyright (C) 2015, Bin Meng <bmeng.cn@gmail.com>
> + *
> + * Adapted from coreboot src/arch/x86/smbios.c
> + *
> + * SPDX-License-Identifier:    GPL-2.0+
> + */
> +
> +#include <common.h>
> +#include <version.h>
> +#include <asm/cpu.h>
> +#include <asm/smbios.h>
> +#include <asm/tables.h>
> +
> +DECLARE_GLOBAL_DATA_PTR;
> +
> +static int smbios_add_string(char *start, const char *str)

Can you please add a comment about what this function does, args and
@return? It seems really bizarre.

> +{
> +       int i = 1;
> +       char *p = start;
> +
> +       for (;;) {
> +               if (!*p) {
> +                       strcpy(p, str);
> +                       p += strlen(str);
> +                       *p++ = '\0';
> +                       *p++ = '\0';
> +
> +                       return i;
> +               }
> +
> +               if (!strcmp(p, str))
> +                       return i;
> +
> +               p += strlen(p) + 1;
> +               i++;
> +       }
> +}
> +
> +static int smbios_string_table_len(char *start)
> +{
> +       char *p = start;
> +       int i, len = 0;
> +
> +       while (*p) {
> +               i = strlen(p) + 1;
> +               p += i;
> +               len += i;
> +       }
> +
> +       return len + 1;
> +}
> +
> +static int smbios_write_type0(u32 *current, int handle)
> +{
> +       struct smbios_type0 *t = (struct smbios_type0 *)*current;
> +       int len = sizeof(struct smbios_type0);
> +
> +       memset(t, 0, sizeof(struct smbios_type0));
> +       t->type = SMBIOS_BIOS_INFORMATION;
> +       t->length = len - SMBIOS_STRUCT_EOS_BYTES;
> +       t->handle = handle;
> +       t->vendor = smbios_add_string(t->eos, "U-Boot");
> +       t->bios_ver = smbios_add_string(t->eos, PLAIN_VERSION);
> +       t->bios_release_date = smbios_add_string(t->eos, U_BOOT_DMI_DATE);
> +       t->bios_rom_size = (CONFIG_ROM_SIZE / 65536) - 1;
> +       t->bios_characteristics = BIOS_CHARACTERISTICS_PCI_SUPPORTED |
> +                                 BIOS_CHARACTERISTICS_SELECTABLE_BOOT |
> +                                 BIOS_CHARACTERISTICS_UPGRADEABLE;
> +#ifdef CONFIG_GENERATE_ACPI_TABLE
> +       t->bios_characteristics_ext1 = BIOS_CHARACTERISTICS_EXT1_ACPI;
> +#endif
> +       t->bios_characteristics_ext2 = BIOS_CHARACTERISTICS_EXT2_TARGET;
> +       t->bios_major_release = 0xff;
> +       t->bios_minor_release = 0xff;
> +       t->ec_major_release = 0xff;
> +       t->ec_minor_release = 0xff;
> +
> +       len = t->length + smbios_string_table_len(t->eos);
> +       *current += len;
> +
> +       return len;
> +}
> +
> +static int smbios_write_type1(u32 *current, int handle)
> +{
> +       struct smbios_type1 *t = (struct smbios_type1 *)*current;
> +       int len = sizeof(struct smbios_type1);
> +
> +       memset(t, 0, sizeof(struct smbios_type1));
> +       t->type = SMBIOS_SYSTEM_INFORMATION;
> +       t->length = len - SMBIOS_STRUCT_EOS_BYTES;
> +       t->handle = handle;

Can we have a common function that sets up this header given the
length? This code seems the same in each function.

> +       t->manufacturer = smbios_add_string(t->eos, CONFIG_SYS_VENDOR);
> +       t->product_name = smbios_add_string(t->eos, CONFIG_SYS_BOARD);
> +
> +       len = t->length + smbios_string_table_len(t->eos);
> +       *current += len;
> +
> +       return len;
> +}
> +
> +static int smbios_write_type3(u32 *current, int handle)
> +{
> +       struct smbios_type3 *t = (struct smbios_type3 *)*current;
> +       int len = sizeof(struct smbios_type3);
> +
> +       memset(t, 0, sizeof(struct smbios_type3));
> +       t->type = SMBIOS_SYSTEM_ENCLOSURE;
> +       t->length = len - SMBIOS_STRUCT_EOS_BYTES;
> +       t->handle = handle;
> +       t->manufacturer = smbios_add_string(t->eos, CONFIG_SYS_VENDOR);
> +       t->chassis_type = SMBIOS_ENCLOSURE_DESKTOP;
> +       t->bootup_state = SMBIOS_STATE_SAFE;
> +       t->power_supply_state = SMBIOS_STATE_SAFE;
> +       t->thermal_state = SMBIOS_STATE_SAFE;
> +       t->security_status = SMBIOS_SECURITY_NONE;
> +
> +       len = t->length + smbios_string_table_len(t->eos);
> +       *current += len;
> +
> +       return len;
> +}
> +
> +static int smbios_write_type4(u32 *current, int handle)
> +{
> +       struct smbios_type4 *t = (struct smbios_type4 *)*current;
> +       int len = sizeof(struct smbios_type4);
> +       const char *vendor;
> +       char *name;
> +       char processor_name[CPU_MAX_NAME_LEN];
> +       struct cpuid_result res;
> +
> +       memset(t, 0, sizeof(struct smbios_type4));
> +       t->type = SMBIOS_PROCESSOR_INFORMATION;
> +       t->length = len - SMBIOS_STRUCT_EOS_BYTES;
> +       t->handle = handle;
> +       t->processor_type = SMBIOS_PROCESSOR_TYPE_CENTRAL;
> +       t->processor_family = gd->arch.x86;
> +       vendor = cpu_vendor_name(gd->arch.x86_vendor);
> +       t->processor_manufacturer = smbios_add_string(t->eos, vendor);
> +       res = cpuid(1);
> +       t->processor_id[0] = res.eax;
> +       t->processor_id[1] = res.edx;
> +       name = cpu_get_name(processor_name);
> +       t->processor_version = smbios_add_string(t->eos, name);
> +       t->status = SMBIOS_PROCESSOR_STATUS_ENABLED;
> +       t->processor_upgrade = SMBIOS_PROCESSOR_UPGRADE_NONE;
> +       t->l1_cache_handle = 0xffff;
> +       t->l2_cache_handle = 0xffff;
> +       t->l3_cache_handle = 0xffff;
> +       t->processor_family2 = t->processor_family;
> +
> +       len = t->length + smbios_string_table_len(t->eos);
> +       *current += len;
> +
> +       return len;
> +}
> +
> +static int smbios_write_type32(u32 *current, int handle)
> +{
> +       struct smbios_type32 *t = (struct smbios_type32 *)*current;
> +       int len = sizeof(struct smbios_type32);
> +
> +       memset(t, 0, sizeof(struct smbios_type32));
> +       t->type = SMBIOS_SYSTEM_BOOT_INFORMATION;
> +       t->length = len - SMBIOS_STRUCT_EOS_BYTES;
> +       t->handle = handle;
> +
> +       *current += len;
> +
> +       return len;
> +}
> +
> +static int smbios_write_type127(u32 *current, int handle)
> +{
> +       struct smbios_type127 *t = (struct smbios_type127 *)*current;
> +       int len = sizeof(struct smbios_type127);
> +
> +       memset(t, 0, sizeof(struct smbios_type127));
> +       t->type = SMBIOS_END_OF_TABLE;
> +       t->length = len - SMBIOS_STRUCT_EOS_BYTES;
> +       t->handle = handle;
> +
> +       *current += len;
> +
> +       return len;
> +}
> +
> +#define update_max(len, max_len, stmt)         \
> +       do {                                    \
> +               int tmp = stmt;                 \
> +               max_len = max(max_len, tmp);    \
> +               len += tmp;                     \
> +       } while (0)
> +
> +u32 write_smbios_table(u32 addr)
> +{
> +       struct smbios_entry *se;
> +       u32 tables;
> +       int len = 0;
> +       int max_struct_size = 0;
> +       int handle = 0;
> +       char *istart;
> +       int isize;
> +
> +       /* 16 byte align the table address */
> +       addr = ALIGN(addr, 16);
> +
> +       se = (struct smbios_entry *)addr;
> +       memset(se, 0, sizeof(struct smbios_entry));
> +
> +       addr += sizeof(struct smbios_entry);
> +       addr = ALIGN(addr, 16);
> +       tables = addr;
> +
> +       /* populate minimum required tables */
> +       update_max(len, max_struct_size, smbios_write_type0(&addr, handle++));
> +       update_max(len, max_struct_size, smbios_write_type1(&addr, handle++));
> +       update_max(len, max_struct_size, smbios_write_type3(&addr, handle++));
> +       update_max(len, max_struct_size, smbios_write_type4(&addr, handle++));
> +       update_max(len, max_struct_size, smbios_write_type32(&addr, handle++));
> +       update_max(len, max_struct_size, smbios_write_type127(&addr, handle++));

I'm not keen on this #define approach. Perhaps this would be better as
a table of functions to call, and a loop that calls them in turn,
updating 'max_struct_size'?

> +
> +       memcpy(se->anchor, "_SM_", 4);
> +       se->length = sizeof(struct smbios_entry);
> +       se->major_ver = SMBIOS_MAJOR_VER;
> +       se->minor_ver = SMBIOS_MINOR_VER;
> +       se->max_struct_size = max_struct_size;
> +       memcpy(se->intermediate_anchor, "_DMI_", 5);
> +       se->struct_table_length = len;
> +       se->struct_table_address = tables;
> +       se->struct_count = handle;
> +
> +       /* calculate checksums */
> +       istart = (char *)se + SMBIOS_INTERMEDIATE_OFFSET;
> +       isize = sizeof(struct smbios_entry) - SMBIOS_INTERMEDIATE_OFFSET;
> +       se->intermediate_checksum = table_compute_checksum(istart, isize);
> +       se->checksum = table_compute_checksum(se, sizeof(struct smbios_entry));
> +
> +       return addr;
> +}
> diff --git a/arch/x86/lib/tables.c b/arch/x86/lib/tables.c
> index f15b2e2..14b15cf 100644
> --- a/arch/x86/lib/tables.c
> +++ b/arch/x86/lib/tables.c
> @@ -7,6 +7,7 @@
>  #include <common.h>
>  #include <asm/sfi.h>
>  #include <asm/mpspec.h>
> +#include <asm/smbios.h>
>  #include <asm/tables.h>
>  #include <asm/acpi_table.h>
>
> @@ -56,4 +57,8 @@ void write_tables(void)
>         rom_table_end = write_acpi_tables(rom_table_end);
>         rom_table_end = ALIGN(rom_table_end, 1024);
>  #endif
> +#ifdef CONFIG_GENERATE_SMBIOS_TABLE
> +       rom_table_end = write_smbios_table(rom_table_end);
> +       rom_table_end = ALIGN(rom_table_end, 1024);
> +#endif
>  }
> diff --git a/doc/README.x86 b/doc/README.x86
> index a4f5321..18fed82 100644
> --- a/doc/README.x86
> +++ b/doc/README.x86
> @@ -764,7 +764,6 @@ TODO List
>  - Audio
>  - Chrome OS verified boot
>  - SMI and ACPI support, to provide platform info and facilities to Linux
> -- Desktop Management Interface (DMI) [15] support
>
>  References
>  ----------
> @@ -782,4 +781,3 @@ References
>  [12] http://events.linuxfoundation.org/sites/events/files/slides/chromeos_and_diy_vboot_0.pdf
>  [13] http://events.linuxfoundation.org/sites/events/files/slides/elce-2014.pdf
>  [14] doc/device-tree-bindings/misc/intel,irq-router.txt
> -[15] http://en.wikipedia.org/wiki/Desktop_Management_Interface
> --
> 1.8.2.1
>

It might be worth adding docs to the README about what tables U-Boot
now supports, how to enable each and what is recommended. There are
quite a few now. My head is spinning!

Regards,
Simon
Bin Meng Oct. 10, 2015, 3:38 a.m. UTC | #2 
Hi Simon,

On Fri, Oct 9, 2015 at 9:02 PM, Simon Glass <sjg@chromium.org> wrote:
> Hi Bin,
>
> On 9 October 2015 at 11:17, Bin Meng <bmeng.cn@gmail.com> wrote:
>> System Management BIOS (SMBIOS) is a specification for how
>> motherboard and system vendors present management information
>> about their products in a standard format by extending the BIOS
>> interface on Intel architecture systems. As of today the latest
>> spec is 3.0 and can be downloaded from DMTF website. This commit
>> adds a simple and minimum required implementation.
>>
>> Signed-off-by: Bin Meng <bmeng.cn@gmail.com>
>> ---
>>
>>  arch/x86/Kconfig              |  11 ++
>>  arch/x86/include/asm/smbios.h | 181 +++++++++++++++++++++++++++++++
>>  arch/x86/lib/Makefile         |   1 +
>>  arch/x86/lib/smbios.c         | 242 ++++++++++++++++++++++++++++++++++++++++++
>>  arch/x86/lib/tables.c         |   5 +
>>  doc/README.x86                |   2 -
>>  6 files changed, 440 insertions(+), 2 deletions(-)
>>  create mode 100644 arch/x86/include/asm/smbios.h
>>  create mode 100644 arch/x86/lib/smbios.c
>
> Looks good - just a few style requests.
>
>>
>> diff --git a/arch/x86/Kconfig b/arch/x86/Kconfig
>> index 5e42d7d..bf09b21 100644
>> --- a/arch/x86/Kconfig
>> +++ b/arch/x86/Kconfig
>> @@ -358,6 +358,17 @@ config GENERATE_ACPI_TABLE
>>           by the operating system. It defines platform-independent interfaces
>>           for configuration and power management monitoring.
>>
>> +config GENERATE_SMBIOS_TABLE
>> +       bool "Generate an SMBIOS (System Management BIOS) table"
>> +       default y
>> +       help
>> +         The System Management BIOS (SMBIOS) specification addresses how
>> +         motherboard and system vendors present management information about
>> +         their products in a standard format by extending the BIOS interface
>> +         on Intel architecture systems.
>> +
>> +         Check http://www.dmtf.org/standards/smbios for details.
>> +
>>  endmenu
>>
>>  config MAX_PIRQ_LINKS
>> diff --git a/arch/x86/include/asm/smbios.h b/arch/x86/include/asm/smbios.h
>> new file mode 100644
>> index 0000000..1fa7d74
>> --- /dev/null
>> +++ b/arch/x86/include/asm/smbios.h
>> @@ -0,0 +1,181 @@
>> +/*
>> + * Copyright (C) 2015, Bin Meng <bmeng.cn@gmail.com>
>> + *
>> + * Adapted from coreboot src/include/smbios.h
>> + *
>> + * SPDX-License-Identifier:    GPL-2.0+
>> + */
>> +
>> +#ifndef _SMBIOS_H_
>> +#define _SMBIOS_H_
>> +
>> +/* SMBIOS spec version implemented */
>> +#define SMBIOS_MAJOR_VER       3
>> +#define SMBIOS_MINOR_VER       0
>> +
>> +/* SMBIOS structure types */
>> +enum {
>> +       SMBIOS_BIOS_INFORMATION = 0,
>> +       SMBIOS_SYSTEM_INFORMATION = 1,
>> +       SMBIOS_SYSTEM_ENCLOSURE = 3,
>> +       SMBIOS_PROCESSOR_INFORMATION = 4,
>> +       SMBIOS_CACHE_INFORMATION = 7,
>> +       SMBIOS_SYSTEM_SLOTS = 9,
>> +       SMBIOS_PHYS_MEMORY_ARRAY = 16,
>> +       SMBIOS_MEMORY_DEVICE = 17,
>> +       SMBIOS_MEMORY_ARRAY_MAPPED_ADDRESS = 19,
>> +       SMBIOS_SYSTEM_BOOT_INFORMATION = 32,
>> +       SMBIOS_END_OF_TABLE = 127
>> +};
>> +
>> +#define SMBIOS_INTERMEDIATE_OFFSET     16
>> +#define SMBIOS_STRUCT_EOS_BYTES                2
>> +
>> +struct __packed smbios_entry {
>> +       u8 anchor[4];
>> +       u8 checksum;
>> +       u8 length;
>> +       u8 major_ver;
>> +       u8 minor_ver;
>> +       u16 max_struct_size;
>> +       u8 entry_point_rev;
>> +       u8 formatted_area[5];
>> +       u8 intermediate_anchor[5];
>> +       u8 intermediate_checksum;
>> +       u16 struct_table_length;
>> +       u32 struct_table_address;
>> +       u16 struct_count;
>> +       u8 bcd_rev;
>> +};
>> +
>> +/* BIOS characteristics */
>> +#define BIOS_CHARACTERISTICS_PCI_SUPPORTED     (1 << 7)
>> +#define BIOS_CHARACTERISTICS_UPGRADEABLE       (1 << 11)
>> +#define BIOS_CHARACTERISTICS_SELECTABLE_BOOT   (1 << 16)
>> +
>> +#define BIOS_CHARACTERISTICS_EXT1_ACPI         (1 << 0)
>> +#define BIOS_CHARACTERISTICS_EXT2_TARGET       (1 << 2)
>> +
>> +struct __packed smbios_type0 {
>> +       u8 type;
>> +       u8 length;
>> +       u16 handle;
>> +       u8 vendor;
>> +       u8 bios_ver;
>> +       u16 bios_start_segment;
>> +       u8 bios_release_date;
>> +       u8 bios_rom_size;
>> +       u64 bios_characteristics;
>> +       u8 bios_characteristics_ext1;
>> +       u8 bios_characteristics_ext2;
>> +       u8 bios_major_release;
>> +       u8 bios_minor_release;
>> +       u8 ec_major_release;
>> +       u8 ec_minor_release;
>> +       char eos[SMBIOS_STRUCT_EOS_BYTES];
>> +};
>> +
>> +struct __packed smbios_type1 {
>> +       u8 type;
>> +       u8 length;
>> +       u16 handle;
>> +       u8 manufacturer;
>> +       u8 product_name;
>> +       u8 version;
>> +       u8 serial_number;
>> +       u8 uuid[16];
>> +       u8 wakeup_type;
>> +       u8 sku_number;
>> +       u8 family;
>> +       char eos[SMBIOS_STRUCT_EOS_BYTES];
>> +};
>> +
>> +#define SMBIOS_ENCLOSURE_DESKTOP       3
>> +#define SMBIOS_STATE_SAFE              3
>> +#define SMBIOS_SECURITY_NONE           3
>> +
>> +struct __packed smbios_type3 {
>> +       u8 type;
>> +       u8 length;
>> +       u16 handle;
>> +       u8 manufacturer;
>> +       u8 chassis_type;
>> +       u8 version;
>> +       u8 serial_number;
>> +       u8 asset_tag_number;
>> +       u8 bootup_state;
>> +       u8 power_supply_state;
>> +       u8 thermal_state;
>> +       u8 security_status;
>> +       u32 oem_defined;
>> +       u8 height;
>> +       u8 number_of_power_cords;
>> +       u8 element_count;
>> +       u8 element_record_length;
>> +       char eos[SMBIOS_STRUCT_EOS_BYTES];
>> +};
>> +
>> +#define SMBIOS_PROCESSOR_TYPE_CENTRAL  3
>> +#define SMBIOS_PROCESSOR_STATUS_ENABLED        1
>> +#define SMBIOS_PROCESSOR_UPGRADE_NONE  6
>> +
>> +struct __packed smbios_type4 {
>> +       u8 type;
>> +       u8 length;
>> +       u16 handle;
>> +       u8 socket_designation;
>> +       u8 processor_type;
>> +       u8 processor_family;
>> +       u8 processor_manufacturer;
>> +       u32 processor_id[2];
>> +       u8 processor_version;
>> +       u8 voltage;
>> +       u16 external_clock;
>> +       u16 max_speed;
>> +       u16 current_speed;
>> +       u8 status;
>> +       u8 processor_upgrade;
>> +       u16 l1_cache_handle;
>> +       u16 l2_cache_handle;
>> +       u16 l3_cache_handle;
>> +       u8 serial_number;
>> +       u8 asset_tag;
>> +       u8 part_number;
>> +       u8 core_count;
>> +       u8 core_enabled;
>> +       u8 thread_count;
>> +       u16 processor_characteristics;
>> +       u16 processor_family2;
>> +       u16 core_count2;
>> +       u16 core_enabled2;
>> +       u16 thread_count2;
>> +       char eos[SMBIOS_STRUCT_EOS_BYTES];
>> +};
>> +
>> +struct __packed smbios_type32 {
>> +       u8 type;
>> +       u8 length;
>> +       u16 handle;
>> +       u8 reserved[6];
>> +       u8 boot_status;
>> +       u8 eos[SMBIOS_STRUCT_EOS_BYTES];
>> +};
>> +
>> +struct __packed smbios_type127 {
>> +       u8 type;
>> +       u8 length;
>> +       u16 handle;
>> +       u8 eos[SMBIOS_STRUCT_EOS_BYTES];
>> +};
>> +
>> +/**
>> + * write_smbios_table() - Write SMBIOS table
>> + *
>> + * This writes SMBIOS table at a given address.
>> + *
>> + * @addr:      start address to write SMBIOS table
>> + * @return:    end address of SMBIOS table
>> + */
>> +u32 write_smbios_table(u32 addr);
>> +
>> +#endif /* _SMBIOS_H_ */
>> diff --git a/arch/x86/lib/Makefile b/arch/x86/lib/Makefile
>> index 169062e..4ac9956 100644
>> --- a/arch/x86/lib/Makefile
>> +++ b/arch/x86/lib/Makefile
>> @@ -30,6 +30,7 @@ obj-y += relocate.o
>>  obj-y += physmem.o
>>  obj-$(CONFIG_X86_RAMTEST) += ramtest.o
>>  obj-y += sfi.o
>> +obj-$(CONFIG_GENERATE_SMBIOS_TABLE) += smbios.o
>>  obj-y  += string.o
>>  obj-$(CONFIG_GENERATE_ACPI_TABLE) += acpi_table.o
>>  obj-y  += tables.o
>> diff --git a/arch/x86/lib/smbios.c b/arch/x86/lib/smbios.c
>> new file mode 100644
>> index 0000000..2cb2d0c
>> --- /dev/null
>> +++ b/arch/x86/lib/smbios.c
>> @@ -0,0 +1,242 @@
>> +/*
>> + * Copyright (C) 2015, Bin Meng <bmeng.cn@gmail.com>
>> + *
>> + * Adapted from coreboot src/arch/x86/smbios.c
>> + *
>> + * SPDX-License-Identifier:    GPL-2.0+
>> + */
>> +
>> +#include <common.h>
>> +#include <version.h>
>> +#include <asm/cpu.h>
>> +#include <asm/smbios.h>
>> +#include <asm/tables.h>
>> +
>> +DECLARE_GLOBAL_DATA_PTR;
>> +
>> +static int smbios_add_string(char *start, const char *str)
>
> Can you please add a comment about what this function does, args and
> @return? It seems really bizarre.
>

Sure.

>> +{
>> +       int i = 1;
>> +       char *p = start;
>> +
>> +       for (;;) {
>> +               if (!*p) {
>> +                       strcpy(p, str);
>> +                       p += strlen(str);
>> +                       *p++ = '\0';
>> +                       *p++ = '\0';
>> +
>> +                       return i;
>> +               }
>> +
>> +               if (!strcmp(p, str))
>> +                       return i;
>> +
>> +               p += strlen(p) + 1;
>> +               i++;
>> +       }
>> +}
>> +
>> +static int smbios_string_table_len(char *start)
>> +{
>> +       char *p = start;
>> +       int i, len = 0;
>> +
>> +       while (*p) {
>> +               i = strlen(p) + 1;
>> +               p += i;
>> +               len += i;
>> +       }
>> +
>> +       return len + 1;
>> +}
>> +
>> +static int smbios_write_type0(u32 *current, int handle)
>> +{
>> +       struct smbios_type0 *t = (struct smbios_type0 *)*current;
>> +       int len = sizeof(struct smbios_type0);
>> +
>> +       memset(t, 0, sizeof(struct smbios_type0));
>> +       t->type = SMBIOS_BIOS_INFORMATION;
>> +       t->length = len - SMBIOS_STRUCT_EOS_BYTES;
>> +       t->handle = handle;
>> +       t->vendor = smbios_add_string(t->eos, "U-Boot");
>> +       t->bios_ver = smbios_add_string(t->eos, PLAIN_VERSION);
>> +       t->bios_release_date = smbios_add_string(t->eos, U_BOOT_DMI_DATE);
>> +       t->bios_rom_size = (CONFIG_ROM_SIZE / 65536) - 1;
>> +       t->bios_characteristics = BIOS_CHARACTERISTICS_PCI_SUPPORTED |
>> +                                 BIOS_CHARACTERISTICS_SELECTABLE_BOOT |
>> +                                 BIOS_CHARACTERISTICS_UPGRADEABLE;
>> +#ifdef CONFIG_GENERATE_ACPI_TABLE
>> +       t->bios_characteristics_ext1 = BIOS_CHARACTERISTICS_EXT1_ACPI;
>> +#endif
>> +       t->bios_characteristics_ext2 = BIOS_CHARACTERISTICS_EXT2_TARGET;
>> +       t->bios_major_release = 0xff;
>> +       t->bios_minor_release = 0xff;
>> +       t->ec_major_release = 0xff;
>> +       t->ec_minor_release = 0xff;
>> +
>> +       len = t->length + smbios_string_table_len(t->eos);
>> +       *current += len;
>> +
>> +       return len;
>> +}
>> +
>> +static int smbios_write_type1(u32 *current, int handle)
>> +{
>> +       struct smbios_type1 *t = (struct smbios_type1 *)*current;
>> +       int len = sizeof(struct smbios_type1);
>> +
>> +       memset(t, 0, sizeof(struct smbios_type1));
>> +       t->type = SMBIOS_SYSTEM_INFORMATION;
>> +       t->length = len - SMBIOS_STRUCT_EOS_BYTES;
>> +       t->handle = handle;
>
> Can we have a common function that sets up this header given the
> length? This code seems the same in each function.

Sure.

>
>> +       t->manufacturer = smbios_add_string(t->eos, CONFIG_SYS_VENDOR);
>> +       t->product_name = smbios_add_string(t->eos, CONFIG_SYS_BOARD);
>> +
>> +       len = t->length + smbios_string_table_len(t->eos);
>> +       *current += len;
>> +
>> +       return len;
>> +}
>> +
>> +static int smbios_write_type3(u32 *current, int handle)
>> +{
>> +       struct smbios_type3 *t = (struct smbios_type3 *)*current;
>> +       int len = sizeof(struct smbios_type3);
>> +
>> +       memset(t, 0, sizeof(struct smbios_type3));
>> +       t->type = SMBIOS_SYSTEM_ENCLOSURE;
>> +       t->length = len - SMBIOS_STRUCT_EOS_BYTES;
>> +       t->handle = handle;
>> +       t->manufacturer = smbios_add_string(t->eos, CONFIG_SYS_VENDOR);
>> +       t->chassis_type = SMBIOS_ENCLOSURE_DESKTOP;
>> +       t->bootup_state = SMBIOS_STATE_SAFE;
>> +       t->power_supply_state = SMBIOS_STATE_SAFE;
>> +       t->thermal_state = SMBIOS_STATE_SAFE;
>> +       t->security_status = SMBIOS_SECURITY_NONE;
>> +
>> +       len = t->length + smbios_string_table_len(t->eos);
>> +       *current += len;
>> +
>> +       return len;
>> +}
>> +
>> +static int smbios_write_type4(u32 *current, int handle)
>> +{
>> +       struct smbios_type4 *t = (struct smbios_type4 *)*current;
>> +       int len = sizeof(struct smbios_type4);
>> +       const char *vendor;
>> +       char *name;
>> +       char processor_name[CPU_MAX_NAME_LEN];
>> +       struct cpuid_result res;
>> +
>> +       memset(t, 0, sizeof(struct smbios_type4));
>> +       t->type = SMBIOS_PROCESSOR_INFORMATION;
>> +       t->length = len - SMBIOS_STRUCT_EOS_BYTES;
>> +       t->handle = handle;
>> +       t->processor_type = SMBIOS_PROCESSOR_TYPE_CENTRAL;
>> +       t->processor_family = gd->arch.x86;
>> +       vendor = cpu_vendor_name(gd->arch.x86_vendor);
>> +       t->processor_manufacturer = smbios_add_string(t->eos, vendor);
>> +       res = cpuid(1);
>> +       t->processor_id[0] = res.eax;
>> +       t->processor_id[1] = res.edx;
>> +       name = cpu_get_name(processor_name);
>> +       t->processor_version = smbios_add_string(t->eos, name);
>> +       t->status = SMBIOS_PROCESSOR_STATUS_ENABLED;
>> +       t->processor_upgrade = SMBIOS_PROCESSOR_UPGRADE_NONE;
>> +       t->l1_cache_handle = 0xffff;
>> +       t->l2_cache_handle = 0xffff;
>> +       t->l3_cache_handle = 0xffff;
>> +       t->processor_family2 = t->processor_family;
>> +
>> +       len = t->length + smbios_string_table_len(t->eos);
>> +       *current += len;
>> +
>> +       return len;
>> +}
>> +
>> +static int smbios_write_type32(u32 *current, int handle)
>> +{
>> +       struct smbios_type32 *t = (struct smbios_type32 *)*current;
>> +       int len = sizeof(struct smbios_type32);
>> +
>> +       memset(t, 0, sizeof(struct smbios_type32));
>> +       t->type = SMBIOS_SYSTEM_BOOT_INFORMATION;
>> +       t->length = len - SMBIOS_STRUCT_EOS_BYTES;
>> +       t->handle = handle;
>> +
>> +       *current += len;
>> +
>> +       return len;
>> +}
>> +
>> +static int smbios_write_type127(u32 *current, int handle)
>> +{
>> +       struct smbios_type127 *t = (struct smbios_type127 *)*current;
>> +       int len = sizeof(struct smbios_type127);
>> +
>> +       memset(t, 0, sizeof(struct smbios_type127));
>> +       t->type = SMBIOS_END_OF_TABLE;
>> +       t->length = len - SMBIOS_STRUCT_EOS_BYTES;
>> +       t->handle = handle;
>> +
>> +       *current += len;
>> +
>> +       return len;
>> +}
>> +
>> +#define update_max(len, max_len, stmt)         \
>> +       do {                                    \
>> +               int tmp = stmt;                 \
>> +               max_len = max(max_len, tmp);    \
>> +               len += tmp;                     \
>> +       } while (0)
>> +
>> +u32 write_smbios_table(u32 addr)
>> +{
>> +       struct smbios_entry *se;
>> +       u32 tables;
>> +       int len = 0;
>> +       int max_struct_size = 0;
>> +       int handle = 0;
>> +       char *istart;
>> +       int isize;
>> +
>> +       /* 16 byte align the table address */
>> +       addr = ALIGN(addr, 16);
>> +
>> +       se = (struct smbios_entry *)addr;
>> +       memset(se, 0, sizeof(struct smbios_entry));
>> +
>> +       addr += sizeof(struct smbios_entry);
>> +       addr = ALIGN(addr, 16);
>> +       tables = addr;
>> +
>> +       /* populate minimum required tables */
>> +       update_max(len, max_struct_size, smbios_write_type0(&addr, handle++));
>> +       update_max(len, max_struct_size, smbios_write_type1(&addr, handle++));
>> +       update_max(len, max_struct_size, smbios_write_type3(&addr, handle++));
>> +       update_max(len, max_struct_size, smbios_write_type4(&addr, handle++));
>> +       update_max(len, max_struct_size, smbios_write_type32(&addr, handle++));
>> +       update_max(len, max_struct_size, smbios_write_type127(&addr, handle++));
>
> I'm not keen on this #define approach. Perhaps this would be better as
> a table of functions to call, and a loop that calls them in turn,
> updating 'max_struct_size'?
>

I will have a try.

>> +
>> +       memcpy(se->anchor, "_SM_", 4);
>> +       se->length = sizeof(struct smbios_entry);
>> +       se->major_ver = SMBIOS_MAJOR_VER;
>> +       se->minor_ver = SMBIOS_MINOR_VER;
>> +       se->max_struct_size = max_struct_size;
>> +       memcpy(se->intermediate_anchor, "_DMI_", 5);
>> +       se->struct_table_length = len;
>> +       se->struct_table_address = tables;
>> +       se->struct_count = handle;
>> +
>> +       /* calculate checksums */
>> +       istart = (char *)se + SMBIOS_INTERMEDIATE_OFFSET;
>> +       isize = sizeof(struct smbios_entry) - SMBIOS_INTERMEDIATE_OFFSET;
>> +       se->intermediate_checksum = table_compute_checksum(istart, isize);
>> +       se->checksum = table_compute_checksum(se, sizeof(struct smbios_entry));
>> +
>> +       return addr;
>> +}
>> diff --git a/arch/x86/lib/tables.c b/arch/x86/lib/tables.c
>> index f15b2e2..14b15cf 100644
>> --- a/arch/x86/lib/tables.c
>> +++ b/arch/x86/lib/tables.c
>> @@ -7,6 +7,7 @@
>>  #include <common.h>
>>  #include <asm/sfi.h>
>>  #include <asm/mpspec.h>
>> +#include <asm/smbios.h>
>>  #include <asm/tables.h>
>>  #include <asm/acpi_table.h>
>>
>> @@ -56,4 +57,8 @@ void write_tables(void)
>>         rom_table_end = write_acpi_tables(rom_table_end);
>>         rom_table_end = ALIGN(rom_table_end, 1024);
>>  #endif
>> +#ifdef CONFIG_GENERATE_SMBIOS_TABLE
>> +       rom_table_end = write_smbios_table(rom_table_end);
>> +       rom_table_end = ALIGN(rom_table_end, 1024);
>> +#endif
>>  }
>> diff --git a/doc/README.x86 b/doc/README.x86
>> index a4f5321..18fed82 100644
>> --- a/doc/README.x86
>> +++ b/doc/README.x86
>> @@ -764,7 +764,6 @@ TODO List
>>  - Audio
>>  - Chrome OS verified boot
>>  - SMI and ACPI support, to provide platform info and facilities to Linux
>> -- Desktop Management Interface (DMI) [15] support
>>
>>  References
>>  ----------
>> @@ -782,4 +781,3 @@ References
>>  [12] http://events.linuxfoundation.org/sites/events/files/slides/chromeos_and_diy_vboot_0.pdf
>>  [13] http://events.linuxfoundation.org/sites/events/files/slides/elce-2014.pdf
>>  [14] doc/device-tree-bindings/misc/intel,irq-router.txt
>> -[15] http://en.wikipedia.org/wiki/Desktop_Management_Interface
>> --
>> 1.8.2.1
>>
>
> It might be worth adding docs to the README about what tables U-Boot
> now supports, how to enable each and what is recommended. There are
> quite a few now. My head is spinning!
>

Do you mean what tables in SMBIOS spec are supported by U-Boot, or
what tables in PIRQ/MP/ACPI/SMBIOS tables are supported by U-Boot?

Regards,
Bin
Simon Glass Oct. 10, 2015, 5:20 a.m. UTC | #3 
Hi Bin,

On 10 October 2015 at 04:38, Bin Meng <bmeng.cn@gmail.com> wrote:
> Hi Simon,
>
> On Fri, Oct 9, 2015 at 9:02 PM, Simon Glass <sjg@chromium.org> wrote:
>> Hi Bin,
>>
>> On 9 October 2015 at 11:17, Bin Meng <bmeng.cn@gmail.com> wrote:
>>> System Management BIOS (SMBIOS) is a specification for how
>>> motherboard and system vendors present management information
>>> about their products in a standard format by extending the BIOS
>>> interface on Intel architecture systems. As of today the latest
>>> spec is 3.0 and can be downloaded from DMTF website. This commit
>>> adds a simple and minimum required implementation.
>>>
>>> Signed-off-by: Bin Meng <bmeng.cn@gmail.com>
>>> ---
>>>
>>>  arch/x86/Kconfig              |  11 ++
>>>  arch/x86/include/asm/smbios.h | 181 +++++++++++++++++++++++++++++++
>>>  arch/x86/lib/Makefile         |   1 +
>>>  arch/x86/lib/smbios.c         | 242 ++++++++++++++++++++++++++++++++++++++++++
>>>  arch/x86/lib/tables.c         |   5 +
>>>  doc/README.x86                |   2 -
>>>  6 files changed, 440 insertions(+), 2 deletions(-)
>>>  create mode 100644 arch/x86/include/asm/smbios.h
>>>  create mode 100644 arch/x86/lib/smbios.c

[snip]

>>> diff --git a/doc/README.x86 b/doc/README.x86
>>> index a4f5321..18fed82 100644
>>> --- a/doc/README.x86
>>> +++ b/doc/README.x86
>>> @@ -764,7 +764,6 @@ TODO List
>>>  - Audio
>>>  - Chrome OS verified boot
>>>  - SMI and ACPI support, to provide platform info and facilities to Linux
>>> -- Desktop Management Interface (DMI) [15] support
>>>
>>>  References
>>>  ----------
>>> @@ -782,4 +781,3 @@ References
>>>  [12] http://events.linuxfoundation.org/sites/events/files/slides/chromeos_and_diy_vboot_0.pdf
>>>  [13] http://events.linuxfoundation.org/sites/events/files/slides/elce-2014.pdf
>>>  [14] doc/device-tree-bindings/misc/intel,irq-router.txt
>>> -[15] http://en.wikipedia.org/wiki/Desktop_Management_Interface
>>> --
>>> 1.8.2.1
>>>
>>
>> It might be worth adding docs to the README about what tables U-Boot
>> now supports, how to enable each and what is recommended. There are
>> quite a few now. My head is spinning!
>>
>
> Do you mean what tables in SMBIOS spec are supported by U-Boot, or
> what tables in PIRQ/MP/ACPI/SMBIOS tables are supported by U-Boot?

I mean the latter. There are quite a few tables and it's not clear
what should be used/enabled, what tables conflict, what Linux does
with them, why it needs them, etc.

Regards,
Simon
Bin Meng Oct. 10, 2015, 7:13 a.m. UTC | #4 
Hi Simon,

On Sat, Oct 10, 2015 at 1:20 PM, Simon Glass <sjg@chromium.org> wrote:
> Hi Bin,
>
> On 10 October 2015 at 04:38, Bin Meng <bmeng.cn@gmail.com> wrote:
>> Hi Simon,
>>
>> On Fri, Oct 9, 2015 at 9:02 PM, Simon Glass <sjg@chromium.org> wrote:
>>> Hi Bin,
>>>
>>> On 9 October 2015 at 11:17, Bin Meng <bmeng.cn@gmail.com> wrote:
>>>> System Management BIOS (SMBIOS) is a specification for how
>>>> motherboard and system vendors present management information
>>>> about their products in a standard format by extending the BIOS
>>>> interface on Intel architecture systems. As of today the latest
>>>> spec is 3.0 and can be downloaded from DMTF website. This commit
>>>> adds a simple and minimum required implementation.
>>>>
>>>> Signed-off-by: Bin Meng <bmeng.cn@gmail.com>
>>>> ---
>>>>
>>>>  arch/x86/Kconfig              |  11 ++
>>>>  arch/x86/include/asm/smbios.h | 181 +++++++++++++++++++++++++++++++
>>>>  arch/x86/lib/Makefile         |   1 +
>>>>  arch/x86/lib/smbios.c         | 242 ++++++++++++++++++++++++++++++++++++++++++
>>>>  arch/x86/lib/tables.c         |   5 +
>>>>  doc/README.x86                |   2 -
>>>>  6 files changed, 440 insertions(+), 2 deletions(-)
>>>>  create mode 100644 arch/x86/include/asm/smbios.h
>>>>  create mode 100644 arch/x86/lib/smbios.c
>
> [snip]
>
>>>> diff --git a/doc/README.x86 b/doc/README.x86
>>>> index a4f5321..18fed82 100644
>>>> --- a/doc/README.x86
>>>> +++ b/doc/README.x86
>>>> @@ -764,7 +764,6 @@ TODO List
>>>>  - Audio
>>>>  - Chrome OS verified boot
>>>>  - SMI and ACPI support, to provide platform info and facilities to Linux
>>>> -- Desktop Management Interface (DMI) [15] support
>>>>
>>>>  References
>>>>  ----------
>>>> @@ -782,4 +781,3 @@ References
>>>>  [12] http://events.linuxfoundation.org/sites/events/files/slides/chromeos_and_diy_vboot_0.pdf
>>>>  [13] http://events.linuxfoundation.org/sites/events/files/slides/elce-2014.pdf
>>>>  [14] doc/device-tree-bindings/misc/intel,irq-router.txt
>>>> -[15] http://en.wikipedia.org/wiki/Desktop_Management_Interface
>>>> --
>>>> 1.8.2.1
>>>>
>>>
>>> It might be worth adding docs to the README about what tables U-Boot
>>> now supports, how to enable each and what is recommended. There are
>>> quite a few now. My head is spinning!
>>>
>>
>> Do you mean what tables in SMBIOS spec are supported by U-Boot, or
>> what tables in PIRQ/MP/ACPI/SMBIOS tables are supported by U-Boot?
>
> I mean the latter. There are quite a few tables and it's not clear
> what should be used/enabled, what tables conflict, what Linux does
> with them, why it needs them, etc.
>

OK, maybe we can document this when ACPI support is ready?

Regards,
Bin
Simon Glass Oct. 10, 2015, 7:25 a.m. UTC | #5 
Hi Bin,

On 10 October 2015 at 08:13, Bin Meng <bmeng.cn@gmail.com> wrote:
> Hi Simon,
>
> On Sat, Oct 10, 2015 at 1:20 PM, Simon Glass <sjg@chromium.org> wrote:
>> Hi Bin,
>>
>> On 10 October 2015 at 04:38, Bin Meng <bmeng.cn@gmail.com> wrote:
>>> Hi Simon,
>>>
>>> On Fri, Oct 9, 2015 at 9:02 PM, Simon Glass <sjg@chromium.org> wrote:
>>>> Hi Bin,
>>>>
>>>> On 9 October 2015 at 11:17, Bin Meng <bmeng.cn@gmail.com> wrote:
>>>>> System Management BIOS (SMBIOS) is a specification for how
>>>>> motherboard and system vendors present management information
>>>>> about their products in a standard format by extending the BIOS
>>>>> interface on Intel architecture systems. As of today the latest
>>>>> spec is 3.0 and can be downloaded from DMTF website. This commit
>>>>> adds a simple and minimum required implementation.
>>>>>
>>>>> Signed-off-by: Bin Meng <bmeng.cn@gmail.com>
>>>>> ---
>>>>>
>>>>>  arch/x86/Kconfig              |  11 ++
>>>>>  arch/x86/include/asm/smbios.h | 181 +++++++++++++++++++++++++++++++
>>>>>  arch/x86/lib/Makefile         |   1 +
>>>>>  arch/x86/lib/smbios.c         | 242 ++++++++++++++++++++++++++++++++++++++++++
>>>>>  arch/x86/lib/tables.c         |   5 +
>>>>>  doc/README.x86                |   2 -
>>>>>  6 files changed, 440 insertions(+), 2 deletions(-)
>>>>>  create mode 100644 arch/x86/include/asm/smbios.h
>>>>>  create mode 100644 arch/x86/lib/smbios.c
>>
>> [snip]
>>
>>>>> diff --git a/doc/README.x86 b/doc/README.x86
>>>>> index a4f5321..18fed82 100644
>>>>> --- a/doc/README.x86
>>>>> +++ b/doc/README.x86
>>>>> @@ -764,7 +764,6 @@ TODO List
>>>>>  - Audio
>>>>>  - Chrome OS verified boot
>>>>>  - SMI and ACPI support, to provide platform info and facilities to Linux
>>>>> -- Desktop Management Interface (DMI) [15] support
>>>>>
>>>>>  References
>>>>>  ----------
>>>>> @@ -782,4 +781,3 @@ References
>>>>>  [12] http://events.linuxfoundation.org/sites/events/files/slides/chromeos_and_diy_vboot_0.pdf
>>>>>  [13] http://events.linuxfoundation.org/sites/events/files/slides/elce-2014.pdf
>>>>>  [14] doc/device-tree-bindings/misc/intel,irq-router.txt
>>>>> -[15] http://en.wikipedia.org/wiki/Desktop_Management_Interface
>>>>> --
>>>>> 1.8.2.1
>>>>>
>>>>
>>>> It might be worth adding docs to the README about what tables U-Boot
>>>> now supports, how to enable each and what is recommended. There are
>>>> quite a few now. My head is spinning!
>>>>
>>>
>>> Do you mean what tables in SMBIOS spec are supported by U-Boot, or
>>> what tables in PIRQ/MP/ACPI/SMBIOS tables are supported by U-Boot?
>>
>> I mean the latter. There are quite a few tables and it's not clear
>> what should be used/enabled, what tables conflict, what Linux does
>> with them, why it needs them, etc.
>>
>
> OK, maybe we can document this when ACPI support is ready?

Anytime is fine with me.

Regards,
Simon
diff mbox

Patch

diff --git a/arch/x86/Kconfig b/arch/x86/Kconfig
index 5e42d7d..bf09b21 100644
--- a/arch/x86/Kconfig
+++ b/arch/x86/Kconfig
@@ -358,6 +358,17 @@  config GENERATE_ACPI_TABLE
 	  by the operating system. It defines platform-independent interfaces
 	  for configuration and power management monitoring.
 
+config GENERATE_SMBIOS_TABLE
+	bool "Generate an SMBIOS (System Management BIOS) table"
+	default y
+	help
+	  The System Management BIOS (SMBIOS) specification addresses how
+	  motherboard and system vendors present management information about
+	  their products in a standard format by extending the BIOS interface
+	  on Intel architecture systems.
+
+	  Check http://www.dmtf.org/standards/smbios for details.
+
 endmenu
 
 config MAX_PIRQ_LINKS
diff --git a/arch/x86/include/asm/smbios.h b/arch/x86/include/asm/smbios.h
new file mode 100644
index 0000000..1fa7d74
--- /dev/null
+++ b/arch/x86/include/asm/smbios.h
@@ -0,0 +1,181 @@ 
+/*
+ * Copyright (C) 2015, Bin Meng <bmeng.cn@gmail.com>
+ *
+ * Adapted from coreboot src/include/smbios.h
+ *
+ * SPDX-License-Identifier:	GPL-2.0+
+ */
+
+#ifndef _SMBIOS_H_
+#define _SMBIOS_H_
+
+/* SMBIOS spec version implemented */
+#define SMBIOS_MAJOR_VER	3
+#define SMBIOS_MINOR_VER	0
+
+/* SMBIOS structure types */
+enum {
+	SMBIOS_BIOS_INFORMATION = 0,
+	SMBIOS_SYSTEM_INFORMATION = 1,
+	SMBIOS_SYSTEM_ENCLOSURE = 3,
+	SMBIOS_PROCESSOR_INFORMATION = 4,
+	SMBIOS_CACHE_INFORMATION = 7,
+	SMBIOS_SYSTEM_SLOTS = 9,
+	SMBIOS_PHYS_MEMORY_ARRAY = 16,
+	SMBIOS_MEMORY_DEVICE = 17,
+	SMBIOS_MEMORY_ARRAY_MAPPED_ADDRESS = 19,
+	SMBIOS_SYSTEM_BOOT_INFORMATION = 32,
+	SMBIOS_END_OF_TABLE = 127
+};
+
+#define SMBIOS_INTERMEDIATE_OFFSET	16
+#define SMBIOS_STRUCT_EOS_BYTES		2
+
+struct __packed smbios_entry {
+	u8 anchor[4];
+	u8 checksum;
+	u8 length;
+	u8 major_ver;
+	u8 minor_ver;
+	u16 max_struct_size;
+	u8 entry_point_rev;
+	u8 formatted_area[5];
+	u8 intermediate_anchor[5];
+	u8 intermediate_checksum;
+	u16 struct_table_length;
+	u32 struct_table_address;
+	u16 struct_count;
+	u8 bcd_rev;
+};
+
+/* BIOS characteristics */
+#define BIOS_CHARACTERISTICS_PCI_SUPPORTED	(1 << 7)
+#define BIOS_CHARACTERISTICS_UPGRADEABLE	(1 << 11)
+#define BIOS_CHARACTERISTICS_SELECTABLE_BOOT	(1 << 16)
+
+#define BIOS_CHARACTERISTICS_EXT1_ACPI		(1 << 0)
+#define BIOS_CHARACTERISTICS_EXT2_TARGET	(1 << 2)
+
+struct __packed smbios_type0 {
+	u8 type;
+	u8 length;
+	u16 handle;
+	u8 vendor;
+	u8 bios_ver;
+	u16 bios_start_segment;
+	u8 bios_release_date;
+	u8 bios_rom_size;
+	u64 bios_characteristics;
+	u8 bios_characteristics_ext1;
+	u8 bios_characteristics_ext2;
+	u8 bios_major_release;
+	u8 bios_minor_release;
+	u8 ec_major_release;
+	u8 ec_minor_release;
+	char eos[SMBIOS_STRUCT_EOS_BYTES];
+};
+
+struct __packed smbios_type1 {
+	u8 type;
+	u8 length;
+	u16 handle;
+	u8 manufacturer;
+	u8 product_name;
+	u8 version;
+	u8 serial_number;
+	u8 uuid[16];
+	u8 wakeup_type;
+	u8 sku_number;
+	u8 family;
+	char eos[SMBIOS_STRUCT_EOS_BYTES];
+};
+
+#define SMBIOS_ENCLOSURE_DESKTOP	3
+#define SMBIOS_STATE_SAFE		3
+#define SMBIOS_SECURITY_NONE		3
+
+struct __packed smbios_type3 {
+	u8 type;
+	u8 length;
+	u16 handle;
+	u8 manufacturer;
+	u8 chassis_type;
+	u8 version;
+	u8 serial_number;
+	u8 asset_tag_number;
+	u8 bootup_state;
+	u8 power_supply_state;
+	u8 thermal_state;
+	u8 security_status;
+	u32 oem_defined;
+	u8 height;
+	u8 number_of_power_cords;
+	u8 element_count;
+	u8 element_record_length;
+	char eos[SMBIOS_STRUCT_EOS_BYTES];
+};
+
+#define SMBIOS_PROCESSOR_TYPE_CENTRAL	3
+#define SMBIOS_PROCESSOR_STATUS_ENABLED	1
+#define SMBIOS_PROCESSOR_UPGRADE_NONE	6
+
+struct __packed smbios_type4 {
+	u8 type;
+	u8 length;
+	u16 handle;
+	u8 socket_designation;
+	u8 processor_type;
+	u8 processor_family;
+	u8 processor_manufacturer;
+	u32 processor_id[2];
+	u8 processor_version;
+	u8 voltage;
+	u16 external_clock;
+	u16 max_speed;
+	u16 current_speed;
+	u8 status;
+	u8 processor_upgrade;
+	u16 l1_cache_handle;
+	u16 l2_cache_handle;
+	u16 l3_cache_handle;
+	u8 serial_number;
+	u8 asset_tag;
+	u8 part_number;
+	u8 core_count;
+	u8 core_enabled;
+	u8 thread_count;
+	u16 processor_characteristics;
+	u16 processor_family2;
+	u16 core_count2;
+	u16 core_enabled2;
+	u16 thread_count2;
+	char eos[SMBIOS_STRUCT_EOS_BYTES];
+};
+
+struct __packed smbios_type32 {
+	u8 type;
+	u8 length;
+	u16 handle;
+	u8 reserved[6];
+	u8 boot_status;
+	u8 eos[SMBIOS_STRUCT_EOS_BYTES];
+};
+
+struct __packed smbios_type127 {
+	u8 type;
+	u8 length;
+	u16 handle;
+	u8 eos[SMBIOS_STRUCT_EOS_BYTES];
+};
+
+/**
+ * write_smbios_table() - Write SMBIOS table
+ *
+ * This writes SMBIOS table at a given address.
+ *
+ * @addr:	start address to write SMBIOS table
+ * @return:	end address of SMBIOS table
+ */
+u32 write_smbios_table(u32 addr);
+
+#endif /* _SMBIOS_H_ */
diff --git a/arch/x86/lib/Makefile b/arch/x86/lib/Makefile
index 169062e..4ac9956 100644
--- a/arch/x86/lib/Makefile
+++ b/arch/x86/lib/Makefile
@@ -30,6 +30,7 @@  obj-y	+= relocate.o
 obj-y += physmem.o
 obj-$(CONFIG_X86_RAMTEST) += ramtest.o
 obj-y += sfi.o
+obj-$(CONFIG_GENERATE_SMBIOS_TABLE) += smbios.o
 obj-y	+= string.o
 obj-$(CONFIG_GENERATE_ACPI_TABLE) += acpi_table.o
 obj-y	+= tables.o
diff --git a/arch/x86/lib/smbios.c b/arch/x86/lib/smbios.c
new file mode 100644
index 0000000..2cb2d0c
--- /dev/null
+++ b/arch/x86/lib/smbios.c
@@ -0,0 +1,242 @@ 
+/*
+ * Copyright (C) 2015, Bin Meng <bmeng.cn@gmail.com>
+ *
+ * Adapted from coreboot src/arch/x86/smbios.c
+ *
+ * SPDX-License-Identifier:	GPL-2.0+
+ */
+
+#include <common.h>
+#include <version.h>
+#include <asm/cpu.h>
+#include <asm/smbios.h>
+#include <asm/tables.h>
+
+DECLARE_GLOBAL_DATA_PTR;
+
+static int smbios_add_string(char *start, const char *str)
+{
+	int i = 1;
+	char *p = start;
+
+	for (;;) {
+		if (!*p) {
+			strcpy(p, str);
+			p += strlen(str);
+			*p++ = '\0';
+			*p++ = '\0';
+
+			return i;
+		}
+
+		if (!strcmp(p, str))
+			return i;
+
+		p += strlen(p) + 1;
+		i++;
+	}
+}
+
+static int smbios_string_table_len(char *start)
+{
+	char *p = start;
+	int i, len = 0;
+
+	while (*p) {
+		i = strlen(p) + 1;
+		p += i;
+		len += i;
+	}
+
+	return len + 1;
+}
+
+static int smbios_write_type0(u32 *current, int handle)
+{
+	struct smbios_type0 *t = (struct smbios_type0 *)*current;
+	int len = sizeof(struct smbios_type0);
+
+	memset(t, 0, sizeof(struct smbios_type0));
+	t->type = SMBIOS_BIOS_INFORMATION;
+	t->length = len - SMBIOS_STRUCT_EOS_BYTES;
+	t->handle = handle;
+	t->vendor = smbios_add_string(t->eos, "U-Boot");
+	t->bios_ver = smbios_add_string(t->eos, PLAIN_VERSION);
+	t->bios_release_date = smbios_add_string(t->eos, U_BOOT_DMI_DATE);
+	t->bios_rom_size = (CONFIG_ROM_SIZE / 65536) - 1;
+	t->bios_characteristics = BIOS_CHARACTERISTICS_PCI_SUPPORTED |
+				  BIOS_CHARACTERISTICS_SELECTABLE_BOOT |
+				  BIOS_CHARACTERISTICS_UPGRADEABLE;
+#ifdef CONFIG_GENERATE_ACPI_TABLE
+	t->bios_characteristics_ext1 = BIOS_CHARACTERISTICS_EXT1_ACPI;
+#endif
+	t->bios_characteristics_ext2 = BIOS_CHARACTERISTICS_EXT2_TARGET;
+	t->bios_major_release = 0xff;
+	t->bios_minor_release = 0xff;
+	t->ec_major_release = 0xff;
+	t->ec_minor_release = 0xff;
+
+	len = t->length + smbios_string_table_len(t->eos);
+	*current += len;
+
+	return len;
+}
+
+static int smbios_write_type1(u32 *current, int handle)
+{
+	struct smbios_type1 *t = (struct smbios_type1 *)*current;
+	int len = sizeof(struct smbios_type1);
+
+	memset(t, 0, sizeof(struct smbios_type1));
+	t->type = SMBIOS_SYSTEM_INFORMATION;
+	t->length = len - SMBIOS_STRUCT_EOS_BYTES;
+	t->handle = handle;
+	t->manufacturer = smbios_add_string(t->eos, CONFIG_SYS_VENDOR);
+	t->product_name = smbios_add_string(t->eos, CONFIG_SYS_BOARD);
+
+	len = t->length + smbios_string_table_len(t->eos);
+	*current += len;
+
+	return len;
+}
+
+static int smbios_write_type3(u32 *current, int handle)
+{
+	struct smbios_type3 *t = (struct smbios_type3 *)*current;
+	int len = sizeof(struct smbios_type3);
+
+	memset(t, 0, sizeof(struct smbios_type3));
+	t->type = SMBIOS_SYSTEM_ENCLOSURE;
+	t->length = len - SMBIOS_STRUCT_EOS_BYTES;
+	t->handle = handle;
+	t->manufacturer = smbios_add_string(t->eos, CONFIG_SYS_VENDOR);
+	t->chassis_type = SMBIOS_ENCLOSURE_DESKTOP;
+	t->bootup_state = SMBIOS_STATE_SAFE;
+	t->power_supply_state = SMBIOS_STATE_SAFE;
+	t->thermal_state = SMBIOS_STATE_SAFE;
+	t->security_status = SMBIOS_SECURITY_NONE;
+
+	len = t->length + smbios_string_table_len(t->eos);
+	*current += len;
+
+	return len;
+}
+
+static int smbios_write_type4(u32 *current, int handle)
+{
+	struct smbios_type4 *t = (struct smbios_type4 *)*current;
+	int len = sizeof(struct smbios_type4);
+	const char *vendor;
+	char *name;
+	char processor_name[CPU_MAX_NAME_LEN];
+	struct cpuid_result res;
+
+	memset(t, 0, sizeof(struct smbios_type4));
+	t->type = SMBIOS_PROCESSOR_INFORMATION;
+	t->length = len - SMBIOS_STRUCT_EOS_BYTES;
+	t->handle = handle;
+	t->processor_type = SMBIOS_PROCESSOR_TYPE_CENTRAL;
+	t->processor_family = gd->arch.x86;
+	vendor = cpu_vendor_name(gd->arch.x86_vendor);
+	t->processor_manufacturer = smbios_add_string(t->eos, vendor);
+	res = cpuid(1);
+	t->processor_id[0] = res.eax;
+	t->processor_id[1] = res.edx;
+	name = cpu_get_name(processor_name);
+	t->processor_version = smbios_add_string(t->eos, name);
+	t->status = SMBIOS_PROCESSOR_STATUS_ENABLED;
+	t->processor_upgrade = SMBIOS_PROCESSOR_UPGRADE_NONE;
+	t->l1_cache_handle = 0xffff;
+	t->l2_cache_handle = 0xffff;
+	t->l3_cache_handle = 0xffff;
+	t->processor_family2 = t->processor_family;
+
+	len = t->length + smbios_string_table_len(t->eos);
+	*current += len;
+
+	return len;
+}
+
+static int smbios_write_type32(u32 *current, int handle)
+{
+	struct smbios_type32 *t = (struct smbios_type32 *)*current;
+	int len = sizeof(struct smbios_type32);
+
+	memset(t, 0, sizeof(struct smbios_type32));
+	t->type = SMBIOS_SYSTEM_BOOT_INFORMATION;
+	t->length = len - SMBIOS_STRUCT_EOS_BYTES;
+	t->handle = handle;
+
+	*current += len;
+
+	return len;
+}
+
+static int smbios_write_type127(u32 *current, int handle)
+{
+	struct smbios_type127 *t = (struct smbios_type127 *)*current;
+	int len = sizeof(struct smbios_type127);
+
+	memset(t, 0, sizeof(struct smbios_type127));
+	t->type = SMBIOS_END_OF_TABLE;
+	t->length = len - SMBIOS_STRUCT_EOS_BYTES;
+	t->handle = handle;
+
+	*current += len;
+
+	return len;
+}
+
+#define update_max(len, max_len, stmt)		\
+	do {					\
+		int tmp = stmt;			\
+		max_len = max(max_len, tmp);	\
+		len += tmp;			\
+	} while (0)
+
+u32 write_smbios_table(u32 addr)
+{
+	struct smbios_entry *se;
+	u32 tables;
+	int len = 0;
+	int max_struct_size = 0;
+	int handle = 0;
+	char *istart;
+	int isize;
+
+	/* 16 byte align the table address */
+	addr = ALIGN(addr, 16);
+
+	se = (struct smbios_entry *)addr;
+	memset(se, 0, sizeof(struct smbios_entry));
+
+	addr += sizeof(struct smbios_entry);
+	addr = ALIGN(addr, 16);
+	tables = addr;
+
+	/* populate minimum required tables */
+	update_max(len, max_struct_size, smbios_write_type0(&addr, handle++));
+	update_max(len, max_struct_size, smbios_write_type1(&addr, handle++));
+	update_max(len, max_struct_size, smbios_write_type3(&addr, handle++));
+	update_max(len, max_struct_size, smbios_write_type4(&addr, handle++));
+	update_max(len, max_struct_size, smbios_write_type32(&addr, handle++));
+	update_max(len, max_struct_size, smbios_write_type127(&addr, handle++));
+
+	memcpy(se->anchor, "_SM_", 4);
+	se->length = sizeof(struct smbios_entry);
+	se->major_ver = SMBIOS_MAJOR_VER;
+	se->minor_ver = SMBIOS_MINOR_VER;
+	se->max_struct_size = max_struct_size;
+	memcpy(se->intermediate_anchor, "_DMI_", 5);
+	se->struct_table_length = len;
+	se->struct_table_address = tables;
+	se->struct_count = handle;
+
+	/* calculate checksums */
+	istart = (char *)se + SMBIOS_INTERMEDIATE_OFFSET;
+	isize = sizeof(struct smbios_entry) - SMBIOS_INTERMEDIATE_OFFSET;
+	se->intermediate_checksum = table_compute_checksum(istart, isize);
+	se->checksum = table_compute_checksum(se, sizeof(struct smbios_entry));
+
+	return addr;
+}
diff --git a/arch/x86/lib/tables.c b/arch/x86/lib/tables.c
index f15b2e2..14b15cf 100644
--- a/arch/x86/lib/tables.c
+++ b/arch/x86/lib/tables.c
@@ -7,6 +7,7 @@ 
 #include <common.h>
 #include <asm/sfi.h>
 #include <asm/mpspec.h>
+#include <asm/smbios.h>
 #include <asm/tables.h>
 #include <asm/acpi_table.h>
 
@@ -56,4 +57,8 @@  void write_tables(void)
 	rom_table_end = write_acpi_tables(rom_table_end);
 	rom_table_end = ALIGN(rom_table_end, 1024);
 #endif
+#ifdef CONFIG_GENERATE_SMBIOS_TABLE
+	rom_table_end = write_smbios_table(rom_table_end);
+	rom_table_end = ALIGN(rom_table_end, 1024);
+#endif
 }
diff --git a/doc/README.x86 b/doc/README.x86
index a4f5321..18fed82 100644
--- a/doc/README.x86
+++ b/doc/README.x86
@@ -764,7 +764,6 @@  TODO List
 - Audio
 - Chrome OS verified boot
 - SMI and ACPI support, to provide platform info and facilities to Linux
-- Desktop Management Interface (DMI) [15] support
 
 References
 ----------
@@ -782,4 +781,3 @@  References
 [12] http://events.linuxfoundation.org/sites/events/files/slides/chromeos_and_diy_vboot_0.pdf
 [13] http://events.linuxfoundation.org/sites/events/files/slides/elce-2014.pdf
 [14] doc/device-tree-bindings/misc/intel,irq-router.txt
-[15] http://en.wikipedia.org/wiki/Desktop_Management_Interface