在spi的flash中创建了文件系统，然后通过Ymodem协议向里面传输文件

// 文件 components/utilities/ymodem/ry_sy.c
static enum rym_code _rym_recv_begin(
    struct rym_ctx *ctx,
    rt_uint8_t *buf,
    rt_size_t len)
{
    struct custom_ctx *cctx = (struct custom_ctx *)ctx;
    cctx->fpath[0] = '/';
    rt_strncpy(&(cctx->fpath[1]), (const char *)buf, len - 1);
    cctx->fd = open(cctx->fpath, O_CREAT | O_WRONLY | O_TRUNC, 0);
    if (cctx->fd < 0)
    {
        rt_err_t err = rt_get_errno();
        rt_kprintf("error creating file: %d\n", err);
        return RYM_CODE_CAN;
    }
    cctx->flen = atoi(1 + (const char *)buf + rt_strnlen((const char *)buf, len - 1));
    if (cctx->flen == 0)
        cctx->flen = -1;
    return RYM_CODE_ACK;
}

// error.h
#define    EPERM 1        /* Not owner */
#define    ENOENT 2    /* No such file or directory */
#define    ESRCH 3        /* No such process */
#define    EINTR 4        /* Interrupted system call */
#define    EIO 5        /* I/O error */
#define    ENXIO 6        /* No such device or address */
#define    E2BIG 7        /* Arg list too long */
#define    ENOEXEC 8    /* Exec format error */
#define    EBADF 9        /* Bad file number */
#define    ECHILD 10    /* No children */
#define    EAGAIN 11    /* No more processes */
#define    ENOMEM 12    /* Not enough space */
#define    EACCES 13    /* Permission denied */
#define    EFAULT 14    /* Bad address */