Systems and methods for supporting BIOS accessibility to traditionally nonaddressable read-only memory space
An information handling system may include a processor and a read-only memory communicatively coupled to the processor and comprising a basic input/output system (BIOS)-accessible region of the read-only memory including a first subregion communicatively coupled to the processor via a first communications interface and a second subregion communicatively coupled to the processor via a second communications interface. The information handling system may also include the BIOS, configured to responsive to a read request from the processor to the BIOS-accessible region determine whether a memory address associated with the read request is within a decoding range of the first subregion, cause the processor to access the first subregion via the first communications interface if the memory address is within the decoding range, and cause the processor to access the second subregion via the second communications interface if the memory address is outside the decoding range.
1. An information handling system comprising:
a processor;
a read-only memory communicatively coupled to the processor and comprising a basic input/output system (BIOS)-accessible region of the read-only memory, wherein the BIOS-accessible region includes:
a first BIOS subregion communicatively coupled to the processor via a first communications interface; and
a second BIOS subregion communicatively coupled to the processor via a second communications interface; and
the BIOS configured to, responsive to a read request from the processor to the BIOS-accessible region:
determine whether a memory address associated with the read request is within a decoding range of the first BIOS subregion;
cause the processor to access the first BIOS subregion via the first communications interface if the memory address is within the decoding range; and
cause the processor to access the second BIOS subregion via the second communications interface if the memory address is outside the decoding range.
2. The information handling system of claim 1 , wherein the read-only memory further comprises a special-purpose region accessible to components of the information handling system other than a BIOS of the information handling system.
3. The information handling system of claim 1 , wherein the first communications interface is a memory-mapped input/output interface.
4. The information handling system of claim 1 , wherein the first communications interface is a serial peripheral interface.
5. A method comprising:
determining, by a basic input/output system (BIOS) of an information handling system, whether a memory address associated with a read request from a processor to a BIOS-accessible region of a read-only memory of the information handling system is within a decoding range of a first BIOS subregion of the BIOS-accessible region;
causing the processor to access the first BIOS subregion via a first communications interface if the memory address is within the decoding range; and
causing the processor to access a second BIOS subregion of the BIOS-accessible region via a second communications interface if the memory address is outside the decoding range.
6. The method of claim 5 , wherein the read-only memory further comprises a special-purpose region accessible to components of the information handling system other than a BIOS of the information handling system.
7. The method of claim 5 , wherein the first communications interface is a memory-mapped input/output interface.
8. The method of claim 5 , wherein the first communications interface is a serial peripheral interface.
9. An article of manufacture comprising:
a non-transitory computer-readable medium; and
computer-executable instructions carried on the computer-readable medium, the instructions readable by a processor, the instructions, when read and executed, for causing the processor to:
determine, by a basic input/output system (BIOS) of an information handling system, whether a memory address associated with a read request from a processor to a BIOS-accessible region of a read-only memory of the information handling system is within a decoding range of a first BIOS subregion of the BIOS-accessible region;
access the first BIOS subregion via a first communications interface if the memory address is within the decoding range; and
access a second BIOS subregion of the BIOS-accessible region via a second communications interface if the memory address is outside the decoding range.
10. The article of claim 9 , wherein the read-only memory further comprises a special-purpose region accessible to components of the information handling system other than a BIOS of the information handling system.
11. The article of claim 9 , wherein the first communications interface is a memory-mapped input/output interface.
12. The article of claim 9 , wherein the first communications interface is a serial peripheral interface.