PSP's GE is a tile-based deferred renderer similar to PowerVR.
uint8_t *ram = calloc(32, 1024*1024); uint8_t *vram = calloc(4, 1024*1024); uint32_t mem_read32(uint32_t addr) if (addr < 0x02000000) return (uint32_t )(ram + addr); if (addr >= 0x04000000 && addr < 0x04200000) return (uint32_t )(vram + (addr & 0x3FFFFF)); if (addr >= 0x1C000000 && addr < 0x20000000) return hw_read(addr); // handle uncached mirrors (bit 29 cleared) return 0;
void mix_audio(int16_t *out, int samples) memset(out, 0, samples * 2 * sizeof(int16_t)); for(int ch = 0; ch < 2; ch++) psp_audio_channel *c = &channels[ch]; if(!c->enabled) continue; for(int i = 0; i < samples; i++) int sample = c->read_sample(c); // resample from source buffer out[i*2 + ch] += sample * c->volume / 0x8000; pc psp emulator
| Start | End | Purpose | |-------|-----|---------| | 0x00000000 | 0x01FFFFFF | Main RAM (32 MB) | | 0x04000000 | 0x041FFFFF | VRAM (4 MB) | | 0x08000000 | 0x0FFFFFFF | Kernel memory (privileged) | | 0x1C000000 | 0x1FFFFFFF | Hardware registers (memory-mapped I/O) | | 0x88000000 | 0x8FFFFFFF | Uncached RAM mirror |
| Module | Purpose | Example HLE | |--------|---------|--------------| | scePower | CPU clock, standby | Return success, ignore | | sceDisplay | Framebuffer flip | Swap host window buffers | | sceCtrl | Input reading | Read keyboard/gamepad | | sceIo | File I/O | Map to host filesystem | | sceKernel | Threads/semaphores | Map to host threads | | sceAudio | Sound output | Queue to audio callback | PSP's GE is a tile-based deferred renderer similar
Implement common modules:
PSP games call functions via syscall or direct jump to kernel (0x80000000+). High-Level Emulation (HLE) is preferred for performance. This guide focuses on the , core components,
This guide focuses on the , core components, and implementation steps. It assumes intermediate knowledge of C/C++, computer architecture, and reverse engineering concepts. Guide: Developing a PSP Emulator for PC 1. Understanding the Target: Sony PSP Hardware | Component | Specification | Emulation Challenge | |-----------|---------------|----------------------| | CPU | MIPS32 R4000 (Allegrex) @ 333 MHz | MIPS interpreter/dynarec, FPU, VFPU (vector unit) | | GPU | "Media Engine" + Rendering Engine @ 166 MHz | OpenGL/Vulkan translation, texture/vertex streaming | | RAM | 32 MB main + 4 MB embedded DRAM (VRAM) | Fast memory mapping, MMU emulation | | Audio | Media Engine + SPU (2 channels, 3D sound) | Buffer mixing, resampling | | Storage | UMD (ISO/CSO), Memory Stick (savedata) | ISO parsing, file system hooks | | OS | ThreadMan, IoFileMgr, PowerCallback, etc. | System call translation | 2. High-Level Emulator Architecture +------------------+ | PSP Game ISO | +------------------+ | v +------------------+ | Loader (PRX/ELF) | +------------------+ | v +------------------+ +------------------+ | CPU Emulation | <-> | Memory Bus | | (Dynarec/Int.) | | (32MB + 4MB) | +------------------+ +------------------+ | | v v +------------------+ +------------------+ | GPU Emulation | | Media Engine | | (OpenGL/Vulkan) | | (Audio/Decode) | +------------------+ +------------------+ | | v v +------------------+ +------------------+ | Host Rendering | | Host Audio API | | (GLFW/SDL2) | | (Pulse/ALSA/XAudio2) +------------------+ +------------------+ 3. Core Components Implementation 3.1 CPU Emulation – MIPS32 + VFPU Option A: Interpreter (simpler, slower)