Re: [PATCH 3/5] smbios: Use SMBIOS 3.0 to support an address above 4GB

On 10/8/23 23:36, 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.

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

include/smbios.h | 22 +++++++++++++++++++++- lib/smbios.c | 22 ++++++++++++++++++---- 2 files changed, 39 insertions(+), 5 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..82e259f31791 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;

@@ -513,13 +517,23 @@ ulong write_smbios_table(ulong addr) */ table_addr = (ulong)map_sysmem(tables, 0); if (sizeof(table_addr) > sizeof(u32) && table_addr > (ulong)UINT_MAX) {

You have to check the end address of the table not the start address here.

The SMBIOS specification says that you should always supply a 32bit SMBIOS entry point. Of course this is not possible on boards that don't have low memory.

In install_smbios_table() this can be achieved by calling efi_allocate_pages() with EFI_MAX_ALLOCATE_TYPE and a maximum address of 4 GiB - 1. Only if this fails use high memory.

Best regards

Heinrich

• 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);
  

• 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;
  

  } else { struct smbios_entry *se;