PE format - RISC-V machine types

[Torinde]

Microsoft PE format

IMAGE_FILE_MACHINE_RISCV32 0x5032 RISC-V 32-bit address space
IMAGE_FILE_MACHINE_RISCV64 0x5064 RISC-V 64-bit address space
IMAGE_FILE_MACHINE_RISCV128 0x5128 RISC-V 128-bit address space

When did Microsoft add those and for what purpose?

[rizwan3d]

Microsoft defines these constants for Windows Portable Executable (PE) files to specify the target architecture of the executable. Each architecture (32-bit, 64-bit, 128-bit) has different capabilities and instruction sets. By defining these constants, Microsoft ensures that the Windows operating system and its tools (like the loader and debugger) can correctly interpret and optimize executables for the specific architecture they are designed for.

The inclusion of RISC-V alongside traditional architectures (like x86 and ARM) signifies Microsoft's intention to support a broader range of hardware. This is crucial for the flexibility and adaptability of Windows in various hardware environments, from IoT devices to high-performance servers.

The PE format is a standard for executables, object code, and DLLs in Windows. By defining these constants, Microsoft maintains a uniform approach to how different architectures are handled within this format, ensuring consistency and reducing the complexity of managing multiple binary types. Including support for RISC-V 128-bit address space, even though such hardware might not be available yet, shows foresight. It prepares the ecosystem for future advancements in hardware capabilities without needing significant overhauls later.