SceLibcPosix

Posix (and extra) compatibility layer for SceLibc

Features over Newlib

• Much faster cached IO over Newlib

  • With FIOS2 and SceLibc stdio as the driving IO backends, cached reads are miles apart
  • Random 4KiB is 48.9x faster using SceLibcPosix, and Reread 4MiB is, and I'm not kidding, over 4000x faster using SceLibcPosix. (Benchmark results in repo)

• SceLibc Auto-Extending Heap for Malloc

  • No more guessing how much memory is necessary, simply add

    unsigned int sceLibcHeapSize = -1; # Upper Limit for Extended Alloc (-1 is unrestricted)
    unsigned int sceLibcHeapExtendedAlloc = 1;
    

• Proper Dynamic Library Support

  • Surpx's built against SceLibcPosix's crt0_module.o will be able to utilize a shared heap. This means full Malloc support in modules and no new C runtime instance.

• Compatiblity with SceLibc dependant modules

• MUSL's structure for contibutions

  • Newlib is, let's face it, a mess when it comes to structure and iterations of features/fixes. I chose musl's structure to allow better readability and ease of development. Most features can be added with a single file, and building simply requires a VitaSDK installation

This is a full replacement for the Newlib C Standard Library

How to use in your projects

Until furthur improvements and integration, there are some extra steps to use this library instead of Newlib

1. -nostdlib -nostartfiles -nodefaultlibs flags need to be used to avoid linking Newlib
2. Link crt0_main.o for Eboots, and crt0_module.o for Suprx Modules (This does not support Skprx, obviously)
3. Remove _newlib_heap_size_user and replace it with unsigned int sceLibcHeapSize
4. Bundle SceLibcPosix.suprx in sce_module/SceLibcPosix.suprx in your VPK
   • If pthreads are needed (C++ or explicitly) link pthread_stub_weak, bundle pthread.suprx in sce_module/pthread.suprx, and add SCE_USER_MODULE_LIST("app0:sce_module/pthread.suprx"); anywhere in your source to ensure it is loaded on application startup.
5. Removing newlib means removing default links as well, so you'd need to restore them, at a minimum

   target_link_libraries(myapp
       -nostdlib
       -nostartfiles
       -nodefaultlibs
       $ENV{VITASDK}/arm-vita-eabi/lib/crt0_main.o #crt0_module.o for suprx
       SceLibcPosix_stub_weak
       SceLibcExt_stub_weak
       SceFios2_stub_weak
       SceLibKernel_stub
       SceIofilemgr_stub
       SceKernelThreadMgr_stub
       SceProcessmgr_stub
       SceSysmem_stub
       SceRtc_stub
       gcc
   )
   

6. You're good to go!

How to Build and Install

1. Install VitaSDK
2. git clone https://github.com/SonicMastr/SceLibcPosix.git --recurse
3. cd SceLibcPosix
4. cmake -B build -S . && cmake --build build && cmake --install build