Usage of mmap command(in directFB)

[kaka <share.kt@gmail.com>]

Hi All,

 

void *mmap(void *start, size_t length, int prot, int flags,           int
fd, off_t offset);
 

I am providing 1.6MB as length parameter in mmap command.

It is giving me error as Can't mmap region with error number EINVAL. I searched for the probable causes for EINVAL error number, and cheked it that i am satisfying all of them

 

on the other hand when i am providing 1.384MB as length parameter in mmap command.

It is successful.
This mmap command is being issued from User space(from the DIrectFB code in systems/fbdev.c)

 

The exact command which i am writing is

addr = mmap(NULL, dfb_fbdev->shared->fix.mmio_len, PROT_READ | PROT_WRITE, MAO_SHARED, dfb_fbdev->fd, 0);

 

Can anybody provide any clue on it?

I want to access the mmio regs at offset (0.9MB to 1.6MB offset).

Also in my system MIPS board(broadcom chip), the framebuffer driver contains support for MMIO length as 1.6MB.

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Thanks & Regards,
kaka

-- 
Thanks & Regards,
kaka