Re: [PATCH v2 3/6] smbios: Use SMBIOS 3.0 to support an address above 4GB

On 10/15/23 04:45, Simon Glass wrote:

When the SMBIOS table is written to an address above 4GB a 32-bit table address is not large enough.

Use an SMBIOS3 table in that case.

Note that we cannot use efi_allocate_pages() since this function has nothing to do with EFI. There is no equivalent function to allocate memory below 4GB in U-Boot. One solution would be to create a separate malloc() pool, or just always put the malloc() pool below 4GB.

Signed-off-by: Simon Glass sjg@chromium.org

Changes in v2:

• Check the end of the table rather than the start.

  include/smbios.h | 22 +++++++++++++++++++++- lib/smbios.c | 24 +++++++++++++++++++----- 2 files changed, 40 insertions(+), 6 deletions(-)

diff --git a/include/smbios.h b/include/smbios.h index c9df2706f5a6..ddabb558299e 100644 --- a/include/smbios.h +++ b/include/smbios.h @@ -12,7 +12,8 @@

/* SMBIOS spec version implemented */ #define SMBIOS_MAJOR_VER 3 -#define SMBIOS_MINOR_VER 0 +#define SMBIOS_MINOR_VER 7

• enum { SMBIOS_STR_MAX = 64, /* Maximum length allowed for a string */

@@ -54,6 +55,25 @@ struct __packed smbios_entry { u8 bcd_rev; };

+struct __packed smbios3_entry {

• u8 anchor[5];
• u8 checksum;
• u8 length;
• u8 major_ver;
• u8 minor_ver;
• u8 docrev;
• u8 entry_point_rev;
• u8 reserved;
• u32 max_struct_size;
• u64 struct_table_address;

+};

+/* These two structures should use the same amount of 16-byte-aligned space */ +static_assert(ALIGN(16, sizeof(struct smbios_entry)) ==

•      ALIGN(16, sizeof(struct smbios3_entry)));
  

• /* BIOS characteristics */ #define BIOS_CHARACTERISTICS_PCI_SUPPORTED (1 << 7) #define BIOS_CHARACTERISTICS_UPGRADEABLE (1 << 11)

diff --git a/lib/smbios.c b/lib/smbios.c index c7a557bc9b7b..92e98388084f 100644 --- a/lib/smbios.c +++ b/lib/smbios.c @@ -487,7 +487,11 @@ ulong write_smbios_table(ulong addr) addr = ALIGN(addr, 16); start_addr = addr;

• addr += sizeof(struct smbios_entry);

• /*

• * So far we don't know which struct will be used, but they both end
  

• * up using the same amount of 16-bit-aligned space
  

• */
  

• addr += max(sizeof(struct smbios_entry), sizeof(struct smbios3_entry)); addr = ALIGN(addr, 16); tables = addr;

@@ -512,14 +516,24 @@ ulong write_smbios_table(ulong addr) * sandbox's DRAM buffer. */ table_addr = (ulong)map_sysmem(tables, 0);

• if (sizeof(table_addr) > sizeof(u32) && table_addr > (ulong)UINT_MAX) {

• if (sizeof(table_addr) > sizeof(u32) && addr >= (ulong)UINT_MAX) {

You have to check the end of the the last SMBIOS structure not the start of the first SMBIOS structure against UINT_MAX.

• struct smbios3_entry *se;
  

  /*
  • We need to put this >32-bit pointer into the table but the
  • field is only 32 bits wide.
  */

• printf("WARNING: SMBIOS table_address overflow %llx\n",
  

•        (unsigned long long)table_addr);
  

• addr = 0;
  

• printf("WARNING: Using SMBIOS3.0 due to table-address overflow %lx\n",
  

•        table_addr);
  

This should be log_debug().

• se = map_sysmem(start_addr, sizeof(struct smbios_entry));
  

• memset(se, '\0', sizeof(struct smbios_entry));
  

• memcpy(se->anchor, "_SM3_", 5);
  

• se->length = sizeof(struct smbios3_entry);
  

• se->major_ver = SMBIOS_MAJOR_VER;
  

• se->minor_ver = SMBIOS_MINOR_VER;
  

• se->docrev = 0;
  

• se->entry_point_rev = 1;
  

• se->max_struct_size = len;
  

• se->struct_table_address = table_addr;
  

You must fill the checksum:

se->checksum = table_compute_checksum(se, sizeof(struct smbios3_entry));

With the checksum filled I can use dmidecode in Linux based on the SMBIOS3 table:

ubuntu@ubuntu:~$ sudo dmidecode # dmidecode 3.5 # SMBIOS3 entry point at 0x27ef53000 Found SMBIOS entry point in EFI, reading table from /dev/mem. SMBIOS 3.7.0 present. # SMBIOS implementations newer than version 3.5.0 are not # fully supported by this version of dmidecode. Table at 0x27EF53020.

Handle 0x0000, DMI type 0, 24 bytes BIOS Information Vendor: U-Boot ...

Best regards

Heinrich

} else { struct smbios_entry *se;