二、在.net micro framework中增加LibTom加解密算法

ゝ一纸荒年。 2022-08-05 02:27 125阅读 0赞

把LibTom加入到工程后,可以顺利编译通过.通过USB下载到板子上面,开心地调用RSA算法,发现有去无回.

.net micro framework调试c/cpp代码是非常不方便的,还好牛人已经给我探索出了方法.

[MDK结合JLINK在调试C/CPP Native工程][MDK_JLINK_C_CPP Native]

用这个调试,发现,libTom使用calloc或者malloc动态分配空间时候,竟然把BUFFER分配到Flash的地址上.....Oh My God....

在群上问了一些人,但是没有任何回复.在Netduion的论坛上面,搜索到一些相关信息.表示不建议使用动态内存.

原文章:[http://forums.netduino.com/index.php?/topic/11718-garbage-collector-sd-card-stream-writer-ram/?hl=malloc\#entry62045][http_forums.netduino.com_index.php_topic_11718-garbage-collector-sd-card-stream-writer-ram_hl_malloc_entry62045]

(To pre-allocate memory for a managed function, just allocate it at the class level. We do this a lot in our driver code. Then use that pre-allocated memory in your function. No dynamic memory allocation or GC required.)

好吧,竟然不行,就重新搞内存管理吧.但只能说理想很美好,现实很骨感.

让我们打一架吧！！！还是失败了.

找呀找呀,怎么在底层使用动态内存呢~~！！竟然发现有tinyhal.h文件中有如下代码:

extern "C" {
    
    void* private_malloc ( size_t len             );
    void  private_free   ( void*  ptr             );
    void* private_realloc( void*  ptr, size_t len );
    
    }

好吧,用他来重定义这两个函数试试.新建一个MEN.C

贴上我的代码

#include <string.h>
    
    typedef unsigned char      BYTE;
    typedef unsigned char*     PBYTE;
    
    typedef unsigned char      UINT8;
    typedef signed   char      INT8;
    
    typedef unsigned short int UINT16;
    typedef signed   short int INT16;
    
    typedef unsigned int       UINT32;
    typedef signed   int       INT32;
    
    typedef unsigned __int64   UINT64;
    typedef signed   __int64   INT64;
    
    typedef unsigned int       size_t;
    
    extern  void* private_malloc ( size_t len             );
    extern  void  private_free   ( void*  ptr             );
    extern  void* private_realloc( void*  ptr, size_t len );
    
    
    
    void *memset(void *s, int c, size_t count)
    {
    	char *xs = s;
    	while (count--)
    		*xs++ = c;
    	return s;
    }
    
    void free(void *ptr)
    {
    	private_free(ptr);
    }
    
    void * malloc(UINT32 size)
    {
    	return private_malloc(size);
    }
    
    void *calloc(size_t n, size_t size)
    {
    	PBYTE lp = private_malloc(n*size);
    	if(lp)
    	{
    		memset(lp,0,n*size);
    	}
    	return lp;
    }
    
    void *realloc(void *ptr,UINT32 size)
    {
    	return private_realloc(ptr,size);		
    }

见证奇迹的时候......

好吧,你已经成功了....

来自:http://blog.csdn.net/lan120576664

[MDK_JLINK_C_CPP Native]: http://blog.csdn.net/norains/article/details/5904617
[http_forums.netduino.com_index.php_topic_11718-garbage-collector-sd-card-stream-writer-ram_hl_malloc_entry62045]: http://forums.netduino.com/index.php?/topic/11718-garbage-collector-sd-card-stream-writer-ram/?hl=malloc#entry62045