Re: Unable to access FPGA device with virtual address returned by ioremap()

On Wed, 25 Dec 2013 16:00:41 -0800, Sri Ram Vemulpali said:

Second, when I typed command in bash "free -m" it shows 756MB memory available. I used "mem=" commandline option to tell kernel to use 4GB memory. But after booting the kernel it still shows 756MB. Why is this?

If it's showing 756M because you have 768M of physical ram (3 x 256M), using mem=4G won't do what you think. That parameter is to *reduce* the amount of memory the kernel will use - it's usually useful on a machine that has (say) 16G, but you want to restrict the kernel to 10G and leave the other 6G for custom hardware or something.