BIOS-BMC Memory Mapping During POST to Cut GPIO Latency

The patent replaces the traditional GPIO-based mechanical/electrical interaction system with a memory-mapped I/O system. The BIOS and BMC communicate through predefined memory addresses rather than through GPIO pins, substituting a slower, more complex physical signaling mechanism with a faster, simpler memory access mechanism. This is achieved by allocating specific memory regions that both BIOS and BMC can access, allowing direct data exchange without GPIO overhead.

The patent substitutes the slow GPIO signaling mechanism with fast memory-access-based communication. By defining specific memory-mapped I/O regions that the BMC can directly access during BIOS execution, the system eliminates the latency inherent in GPIO read/write operations. The BMC writes configuration data directly to predefined memory addresses, and the BIOS reads from these addresses immediately, creating a low-latency communication channel.

The patent performs preliminary actions during system initialization to set up the memory-mapped I/O communication channel. The BIOS allocates specific memory regions and configures the BMC with the appropriate memory addresses before actual interaction begins. This preliminary setup, including defining memory boundaries and access permissions, eliminates the need for complex runtime negotiation and simplifies subsequent communication operations.