i.MX Processorsのトピックproblem in mmap b/w user and kernel space

problem in mmap b/w user and kernel space

vijeshreddy — Sat, 09 Dec 2017 07:01:22 GMT

I am trying to mmap some memory b/w user space and kernel space so that I can use it as a shared memory area.

I tried a sample code from internet in which the following functions were used.

1. mem_map_reserve(page);

2. remap_page_range(start, page, PAGE_SIZE, PAGE_SHARED))

and an include file #include <linux/wrapper.h> was used.

If I compile the same code for imx6 i am getting <linux/wrapper.h> - no such file error , if I am not including the file - i am getting an error - implicit declaration of remap_page_range()

Please let me know which include i have to use to eliminate the error or is there any better way to mmap some memory between user and kernel space.

Thanks in advance.

Vijesh.

Re: problem in mmap b/w user and kernel space

igorpadykov — Mon, 11 Dec 2017 04:48:24 GMT

Hi Vijesh

what android release used in the case. In general one can try to rebuild from scratch,

to avoid possibilty for using old headers. Also similar issues one can find by googling, like
mmap causes compile errors on r15c (unknown identifier) · Issue #477 · android-ndk/ndk · GitHub

Best regards
igor
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Re: problem in mmap b/w user and kernel space

vijeshreddy — Mon, 11 Dec 2017 05:34:58 GMT

I am using linux 4.1.18-i.MX6-PD15.3.0

Re: problem in mmap b/w user and kernel space

igorpadykov — Mon, 11 Dec 2017 06:34:11 GMT

this is not supported by nxp, please try nxp official releases described on

http://www.nxp.com/products/software-and-tools/software-development-tools/i.mx-software-and-tools/i.mx-6series-i.mx-7series-software-and-development-tool-resources:IMX_SW

Best regards
igor