RT-thread smart动态加载

发布于 2021-11-15 18:17:33 浏览：1390 订阅该版

大神你好，在lwp_elf_reloc函数中，前面已经重定位了所有的符号（按我的理解即修改了对应的GOT表），
```c
        if ((v2 & 0xff) == R_ARM_RELATIVE)
        {
            // *(uint32_t*)(text_start + v1) += (uint32_t)text_start;
            *(uint32_t*)addr += (uint32_t)text_start;
        }
        else if ((v2 & 0xff) == R_ARM_ABS32)
        {
            uint32_t t;
            t = (v2 >> 8);
            if (t) /* 0 is UDF */
            {
                // *(uint32_t*)(text_start + v1) = (uint32_t)(text_start + dynsym[t].st_value);
                *(uint32_t*)addr = (uint32_t)(text_start + dynsym[t].st_value);
            }
        }
```

但后面再次修改GOT,不知怎么理解，求解答原理？
```c
    if (got_size)
    {
        uint32_t *got_item = (uint32_t*)got_start;

for (rel_off = 0; rel_off < got_size; rel_off += 4, got_item++)
        {
            //*got_item += (uint32_t)text_start;
            addr = rt_hw_mmu_v2p(m_info, got_item);
            addr -= PV_OFFSET;
            *(uint32_t *)addr += (uint32_t)text_start;
        }
    }
```