Runtime access to firmware platform configuration data
During boot time of a computing system, a human-readable lookup table is utilized to generate a binary lookup table. At runtime, a hook to a function for reading or setting a firmware variable receives a request in a custom format or a standard format. If the request is in the custom format, the hook locates a mapping identifier (ID) associated with a setup question value to be read or set and a performs a lookup operation in the binary lookup table for the mapping ID. The hook retrieves the offset and bit width associated with the setup question value to be read or set from the binary lookup table. The hook then performs the requested get or set operation using the offset and width for the value and a conventional firmware function for getting or setting a firmware variable.
1. A computing device, comprising:
one or more processors; and
at least one non-transitory computer-readable storage medium having computer-executable instructions stored thereupon which, when executed by the one or more processors, cause the computing device to:
receive a request, by way of a firmware executing on the computing device, to get or set a setup question value;
responsive to receiving the request, determine if the request is in a first format or a second format different from the first format;
responsive to determining that the request is in a first format,
identify a mapping identifier (ID) associated with the setup question value,
perform a lookup operation in a lookup table using the mapping ID to determine an offset and bit width associated with the setup question value, and
perform a firmware runtime function to get or set the setup question value using the offset and bit width associated with the setup question value; and
responsive to determining the request has a second format, perform the firmware runtime function to get or set the setup question value.
2. The computing device of claim 1 , wherein the lookup table is in a binary format, wherein the lookup table is generated from a lookup table in a human-readable format, and wherein the lookup table in the human-readable format is generated at a build time of the firmware.
3. The computing device of claim 2 , wherein the request is received from an application executing on an operating system on the computing device, and wherein the lookup table in the human-readable format is made available to the application by way of an advanced configuration and power interface (ACPI).
4. The computing device of claim 1 , wherein the request is received from an application executing on an operating system on the computing device, and wherein the request is received at a system management mode (SMM) handler executing in the firmware.
5. The computing device of claim 1 , wherein the requested is received by way of a windows management interface (WMI).
6. The computing device of claim 1 , wherein the at least one non-transitory computer-readable storage medium has further computer-executable instructions stored thereupon to:
return the setup question value in response to the request if the request comprises a request to perform a firmware runtime function to get a setup question value; or
return a status in response to the request if the request comprises a request to perform a firmware runtime function to set a setup question value.
7. The computing device of claim 1 , wherein a function hook receives the request to perform the firmware runtime function to get or set the setup question value, and wherein the function hook is configured to call a get or set function provided by the firmware to perform the firmware runtime function to get or set the setup question value.
8. The computing device of claim 7 , wherein the set function is configured to:
read a firmware variable containing the setup question value from a non-volatile memory;
modify the firmware variable at the offset with a new values for the setup question value; and
store the modified firmware variable in the non-volatile memory.
9. A non-transitory computer-readable storage medium having computer-executable instructions stored thereupon which, when executed by a computing device, cause the computing device to:
receive a request, by way of a firmware executing on the computing device, to perform a firmware runtime function to get or set a setup question value;
responsive to receiving the request, determine if the request is in a first format or a second format different from the first format;
responsive to determining that the request is in a first format,
identify a mapping identifier (ID) associated with the setup question value,
perform a lookup operation in a lookup table using the mapping ID to determine an offset and bit width associated with the setup question value, and
perform the firmware runtime function to get or set the setup question value using the offset and bit width associated with the setup question value; and
responsive to determining the request has a second format, perform the firmware runtime function to get or set the setup question value.
10. The non-transitory computer-readable storage medium of claim 9 , wherein the lookup table is in a binary format, wherein the lookup table is generated from a lookup table in a human-readable format, and wherein the lookup table in the human-readable format is generated at a build time of the firmware.
11. The non-transitory computer-readable storage medium of claim 10 , wherein the request is received from an application executing on an operating system on the computing device, and wherein the lookup table in the human-readable format is made available to the application by way of an advanced configuration and power interface (ACPI).
12. The non-transitory computer-readable storage medium of claim 9 , wherein the request is received from an application executing on an operating system on the computing device, and wherein the request is received at a system management mode (SMM) handler executing in the firmware.
13. The non-transitory computer-readable storage medium of claim 9 , wherein the requested is received by way of a windows management interface (WMI).
14. The non-transitory computer-readable storage medium of claim 9 , having further computer-executable instructions stored thereupon to:
return the setup question value in response to the request if the request comprises a request to perform a firmware runtime function to get the setup question value; or
return a status in response to the request if the request comprises a request to perform a firmware runtime function to set the setup question value.
15. The non-transitory computer-readable storage medium of claim 9 , wherein a function hook receives the request to perform the firmware runtime function to get or set the setup question value, and wherein the function hook is configured to call a get or set function provided by the firmware to perform the firmware runtime function to get or set the setup question value.
16. A computer-implemented method performed by a computing device, the method comprising:
receiving a request, by way of a firmware executing on the computing device, to perform a firmware runtime function to get or set a setup question value;
responsive to receiving the request, determining if the request is in a first format or a second format different from the first format;
responsive to determining that the request is in a first format,
identifying a mapping identifier (ID) associated with the setup question value,
performing a lookup operation in a lookup table using the mapping ID to determine an offset and bit width associated with the setup question value, and
performing the firmware runtime function to get or set the setup question value using the offset and bit width associated with the setup question value; and
responsive to determining the request has a second format, performing the firmware runtime function to get or set the setup question value.
17. The computer-implemented method of claim 16 , wherein the lookup table is in a binary format, wherein the lookup table is generated from a lookup table in a human-readable format, and wherein the lookup table in the human-readable format is generated at a build time of the firmware.
18. The computer-implemented method of claim 17 , wherein the request is received from an application executing on an operating system on the computing device, and wherein the lookup table in the human-readable format is made available to the application by way of an advanced configuration and power interface (ACPI).
19. The computer-implemented method of claim 16 , wherein the request is received from an application executing on an operating system on the computing device, and wherein the request is received at a system management mode (SMM) handler executing in the firmware.
20. The computer-implemented method of claim 16 , further comprising:
returning the setup question value in response to the request if the request comprises a request to perform a firmware runtime function to get a setup question value; or
returning a status in response to the request if the request comprises a request to perform a firmware runtime function to set a setup question value.