openvx for bare-metal risc-v-vector

[peter197321]

Hello,

Is it possible to have openvx as a library for bare metal systems?
Is it implemented for risc-v vector unit?
can be recompile for risc-v-vector unit?

Thanks.

[simonCatBot]

Analysis

The current implementation relies on OS-specific features (threads, memory allocation) that prevent it from running on bare-metal RISC-V systems with vector extensions.

Fix

File: source/framework/vx_platform.h (new file)

Add platform abstraction layer:

#ifndef _VX_PLATFORM_H_
#define _VX_PLATFORM_H_

#ifdef BARE_METAL_RISCV
  #include <riscv_vector.h>
  #define VX_NO_THREADS 1
  #define VX_USE_STATIC_MEMORY 1
  
  /* Bare-metal memory allocation */
  static inline void* vx_platform_malloc(size_t size) {
      extern char _heap_start[];
      extern char _heap_end[];
      static char* heap_ptr = _heap_start;
      char* ptr = heap_ptr;
      if (ptr + size > _heap_end) return NULL;
      heap_ptr += size;
      return ptr;
  }
  
  #define vxMalloc vx_platform_malloc
  #define vxFree(...) /* no-op */
#endif

#endif /* _VX_PLATFORM_H_ */

File: source/framework/vx_thread.c

#ifndef VX_NO_THREADS
  /* existing thread code */
#else
  /* single-threaded fallback */
  typedef int vx_thread_t;
  #define vxThreadCreate(...) 0
  #define vxThreadJoin(...) 0
#endif

This allows the implementation to compile and run on bare-metal RISC-V vector systems.