8. Protocols - Device Path Protocol¶
8.1. Introduction¶
This section adds two device path node types that describe files stored in firmware volumes:
Firmware File Media Device Path
Firmware Volume Media Device Path
These device path nodes are used by a DXE-aware updated UEFI Boot
Service LoadImage() to load UEFI images from firmware volumes.
This new capability is used by the DXE Dispatcher to load DXE
drivers from firmware volumes.
8.2. Firmware Volume Media Device Path¶
This type is used by systems implementing the PI architecture specifications to describe a firmware volume.
Mnemonic |
Byte Offset |
Byte Length |
Description |
|---|---|---|---|
Type |
0 |
1 |
Type 4 – Media Device Path |
Sub-Type |
1 |
1 |
Sub Type 7 – Firmware Volume Media Device Path |
Length |
2 |
2 |
Length of this structure in bytes. Length is 20 bytes |
Firmware Volume Name |
4 |
16 |
Firmware volume name. Type EFI_GUID |
Device Node Type/Subtype/Other |
Description |
|---|---|
Type: 4 (Media Device Path)
Sub Type: 7 (Firmware Volume)
|
Fv (fv guid)The
fv guid is a GUID. |
8.3. Firmware File Media Device Path¶
This type is used by systems implementing the PI architecture specifications to describe a firmware file in a firmware volume.
Mnemonic |
Byte Offset |
Byte Length |
Description |
|---|---|---|---|
Type |
0 |
1 |
Type 4 – Media Device Path |
Sub-Type |
1 |
1 |
Sub Type 6 – Firmware File Media Device Path |
Length |
2 |
2 |
Length of this structure in bytes. Length is 20 bytes. |
Firmware File Name |
4 |
16 |
Firmware file name. Type EFI_GUID. |
Device Node Type/Subtype/Other |
Description |
|---|---|
Type: 4 (Media Device Path)
Sub Type: 6 (Firmware File)
|
FvFile (fvfile-guid)The
fvfile guid is a GUID. |