Patina SMBIOS Component

The Patina SMBIOS component provides type-safe SMBIOS table management for Patina-based firmware. It offers both a modern Rust service API and legacy C/EDKII protocol compatibility for managing SMBIOS records throughout the boot process.

Capabilities

• Produces the Smbios service for adding, updating, and publishing SMBIOS records with type-safe structured record types.
• Installs the EDKII-compatible EFI_SMBIOS_PROTOCOL for C drivers that need to interact with SMBIOS tables.
• Manages SMBIOS record handles with automatic allocation, reuse, and PI specification compliance.
• Validates and serializes structured SMBIOS records with proper string pool handling.
• Publishes SMBIOS tables to the UEFI Configuration Table with proper entry point structures and checksums.
• Emits focused log output to aid in debugging record addition, string updates, and table publication.

Components and Services

• SmbiosProvider component: Creates the SMBIOS manager, registers the Service<dyn Smbios>, and installs the C/EDKII protocol. Both interfaces share the same underlying manager for consistency.
• Smbios trait: Defines core operations (version, publish_table, update_string, remove, add_from_bytes) accessible through trait object dynamic dispatch.
• SmbiosExt trait: Provides the type-safe add_record<T>() generic method for adding structured records without manual serialization.

Configuration

The SMBIOS component requires version configuration during instantiation:

commands.add_component(SmbiosProvider::new(3, 9));  // SMBIOS 3.9

Only SMBIOS 3.x versions are supported. The component will panic at initialization if SmbiosProvider::new() is called with an unsupported major version (i.e., major version != 3). This is intentional to catch configuration errors early during platform development. If the manager creation fails during entry_point(), the component returns EfiError::Unsupported instead of panicking.

Integration Guidance

Adding SMBIOS Records

Platform components should use the type-safe add_record<T>() method from SmbiosExt:

use patina::component::service::Service;
use patina_smbios::{
    service::{Smbios, SmbiosExt, SmbiosTableHeader, SMBIOS_HANDLE_PI_RESERVED},
    smbios_record::Type0PlatformFirmwareInformation,
};

fn platform_init(smbios: Service<dyn Smbios>) -> Result<()> {
    // Create a Type 0 BIOS Information record
    let bios_info = Type0PlatformFirmwareInformation {
        header: SmbiosTableHeader::new(0, 0, SMBIOS_HANDLE_PI_RESERVED),
        vendor: 1,
        firmware_version: 2,
        bios_starting_address_segment: 0xE800,
        firmware_release_date: 3,
        firmware_rom_size: 0xFF,
        characteristics: 0x08,
        characteristics_ext1: 0x03,
        characteristics_ext2: 0x03,
        system_bios_major_release: 1,
        system_bios_minor_release: 0,
        embedded_controller_major_release: 0xFF,
        embedded_controller_minor_release: 0xFF,
        extended_bios_rom_size: 0,
        string_pool: vec![
            String::from("Patina Firmware"),
            String::from("1.0.0"),
            String::from("10/31/2025")
        ],
    };

    // Add the record and get the assigned handle
    let handle = smbios.add_record(None, &bios_info)?;
    log::info!("Added BIOS Info record with handle: 0x{:04X}", handle);

    // Publish the table when all records are added
    smbios.publish_table()?;
    Ok(())
}

Available Record Types

The crate provides structured types for common SMBIOS records:

• Type0PlatformFirmwareInformation: BIOS/firmware information
• Type1SystemInformation: System manufacturer, product name, UUID, SKU
• Type2BaseboardInformation: Baseboard/motherboard information
• Type3SystemEnclosure: Chassis/enclosure information
• Type127EndOfTable: End-of-table marker (required)

Each record type implements SmbiosRecordStructure and handles serialization automatically, including proper string pool conversion and length calculations.

String Pool Handling

SMBIOS strings are stored in a Vec<String> field marked with #[string_pool]. String indices in record fields are 1-based. The serialization process automatically converts the string pool to null-terminated SMBIOS format:

string_pool: vec![
    String::from("Vendor"),      // Index 1
    String::from("Product"),     // Index 2
    String::from("Version"),     // Index 3
],

Updating Existing Records

Records can be updated after creation using update_string:

// Update string 1 in the record
smbios.update_string(handle, 1, "New Vendor Name")?;

C/EDKII Protocol Compatibility

The component automatically installs the EFI_SMBIOS_PROTOCOL with functions:

• Add: Add SMBIOS records from raw bytes
• UpdateString: Update strings in existing records
• Remove: Remove records by handle
• GetNext: Iterate through SMBIOS records

C drivers can locate and use this protocol as they would in traditional EDKII firmware.

Testing

The crate includes comprehensive unit tests demonstrating:

• Record creation and serialization
• Handle allocation and reuse
• String pool validation
• Mock service patterns using Service::mock()
• Integration with the service system

Run tests with:

cargo test --lib

Documentation

For detailed implementation and architectural information, see the inline documentation and:

• SMBIOS Specification