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This article mainly introduces the Linux kernel device driver address mapping example analysis, the article is very detailed, has a certain reference value, interested friends must read it!

# include # define ioremap (cookie,size) _ arm_ioremap (cookie,size, MT_DEVICE) / / cookie represents the physical address, and size represents the mapping size. Ioremap maps the specified physical address to the idle virtual address void _ _ iomem * _ arm_ioremap (unsigned long phys_addr, size_t size, unsigned int mtype) {return_ _ arm_ioremap_caller (phys_addr, size, mtype,__builtin_return_address (0));}

1. Virtual address mapped according to physical address

Virtual address = ioremap (physical address, how big is the mapping)

Iounmap (virtual address) after use; / / delete the mapping table

two。

Ioread8 (address) / readb () ioread16 (address) / readw () ioread32 (address) / readl () iowrite8 (value, address) / writebiowrite16 (value, address) / writewiowrite32 (value, address) / writel#include SZ_4KSZ_1M are all the contents of the article "example Analysis of Linux Kernel device driver address Mapping". Thank you for reading! Hope to share the content to help you, more related knowledge, welcome to follow the industry information channel!

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