- 论坛徽章:
- 4
|
5可用积分
本帖最后由 chishanmingshen 于 2013-03-17 19:04 编辑
Based on this discussion, you might also want to map addresses returned by ioremap to user space. That would be a mistake, however; addresses from ioremap are special and cannot be treated like normal kernel virtual addresses. Instead, you should use remap_pfn_range to remap I/O memory areas into user space.
Ldd3这段如何理解?请指点,谢谢! |
最佳答案
查看完整内容
尝试这样理解:1. 这里说的normal kernel virtual addresses理解为直接物理RAM映射而来,启动过程决定,运行时不可更改,可重映射2. ioremap得到的地址是内核空间vmalloc区,运行时映射得到地址、取消映射后该地址可被其它映射使用,该地址不可重映射
|