write2ddr

功能：应用层向DDR指定地址写入指定长度的指定数据（/dev/mem和mmap函数）

第一个参数：ddr的基地址

第二个参数：编移地址

第三个参数：要写入多大内存

第四个参数：写入入的数据

实现：dev/mem+mmap函数

写好后，32位机器可以用，但是64位机器不可以用，比如基她址传入0x100000000，8个0，已经超出32位地址所能表达的最大数ox1fffffff。怎么在64机器上传入超32位的Oxfffffff的地数据？

• strtoull西数似乎只能转换到32位的。

• 用sscanf函数进行数据转换。

/* 2019.10.15 by zhilu */
#include <stdio.h>
#include <unistd.h>
#include <sys/mman.h>
#include <sys/types.h>
#include <sys/stat.h>
#include <fcntl.h>

/* help information */
void do_help(char* argv0)
{
    printf("%s -h help information\n", argv0);
    printf("%s <base address > <offset address> <limit> <data>\n", argv0);
}

/ manipulation function »/
int do_write_func(unsigned long long base_addr, unsigned long long offset_addr, unsigned long long limit, char data)
{
    unsigned char *map_base:
    unsigned long long mem_base_addr = 0;
    unsigned long long tmp_addr = 0;
    int len = 0;
    int fd = -1;
    int i = 0:
    unsigned long addr;
    unsigned char content;

    fd = open ("/dev/mem" , O_RDWR|0_SYNC);
    if(fd < 0)
        return -1;
    mem_base_addr = base_addr + offset_addr;
    tmp_addr = mem_base_addr % (0x1000);
    mem_base_addr = mem_base_addr - tmp_addr:

    map_base = mmap(NULL, limit, PROT_READ| PROT_WRITE, MAP_SHARED, fd, mem_base_addr);
    //printf("map_base = Ox%p\n",map_base );
    if (map_base == 0) {
        printf("NULL pointer!\n");
        return -1;
    } else {
        printf("init ok!\n");
    }

    for (i=0 ; i < limit; ++i)
    {
        //content = * (map_base+tmp_addr+i);
        //printf("address: Ox%p content Ox%x\t\t", &map_base[tmp_addr+i), content);
        *(map_base+tmp_addr+i) = (unsigned char)data;
        //content = *(map_base+tmp_addr+i);

        //printf("updated address: Ox%p content 0x%x\n", &map_base[tmp_addr+1], content);
    }
    close (fd);
    munmap(map_base, limit);
    return 0;
}
/* main function */
int main(int argc, char** argv)
{
    int ret;
    unsigned long long base_addr;

    if(argc != 5) { 
        do_help(argv[0]);
    } else {
        sscanf(argv[1], "%11x", &base_addr);
        ret = do_write_func(base_addr, strtoul1(argv[2], 0, 16), strtoul1(argv[3], 0, 16), strtoul1(a rgv[4], 0, 16));
    if (ret < 0) {
        printf("write failed!\n");
    }
    printf("write successful!\n\n");
    return 0;
}