Frame buffer region redirection for multiple graphics adapters

A method of accessing a frame buffer that is divided between multiple graphics devices as a unified frame buffer, comprising:

• defining a redirection region corresponding to a bloated register space within a prefetchable memory space and a remap region within the prefetchable memory space for storing image data for display on a display device, wherein each memory address in the remap region is associated with each of the multiple graphics devices, and wherein a first graphics device is configured to specify a bloated register space requirement that indicates the size of the bloated register space, within the prefetchable memory address space;
• dividing the redirection region into a plurality of portions, each portion of the redirection region being associated with a different one of the multiple graphics devices;
• and
• outputting the access to one or more of the multiple graphics devices depending on whether an address associated with the access is either within the redirection region or within the remap region,
• wherein the memory access is output to two or more of the multiple graphics devices when the address associated with the memory access is within the remap region and outside the redirection region.

A bridge device for interfacing between a host processor and multiple graphics devices, comprising:

• a first register configured to store a value specifying a prefetchable memory space;
• a redirection register configured to store a first memory range defining a redirection region corresponding to a bloated register space within the prefetchable memory space, wherein the redirection region is divided into a plurality of portions respectively adapted to store image data for display on a display device, each portion associated with a different one of the multiple graphics devices;
• a remap register configured to store a second memory range defining a remap region within the prefetchable memory space, wherein the remap region is associated with each of the multiple graphics devices;
• and
• a memory access unit configured to transmit accesses to one or more ports based on the first register, the redirection register, and the remap register, wherein each of the one or more ports is coupled to a different one of the multiple graphics devices,
• wherein the memory access unit is configured to output a memory access associated with an address within the prefetchable memory space to two or more of the ports when the address is within the second memory range and outside the first memory range, and
• wherein a first graphics device is configured to specify a bloated register space requirement that indicates the size of the bloated register space within the prefetchable memory address space.