memmap in FreeBSD

[maneesh]

[size=-1][Duplicate thread removed -- mod][/size]

What is the memmap equivalent of Linux in Freebsd. FreeBSD?

In Linux memmap is used to reserve a portion of physical memory. This is used as a kernel boot argument. E.g.: memmap=2G$1G will reserve 1[ ]GB memory above 2[ ]GB in[ ] case I have 3[ ]GB RAM. This 1[ ]GB reserved memory is not visible to the OS, however this 1[ ]GB can be used using iorema. How can I reserve memory in Freebsd FreeBSD and later use it, i.e memmap and ioremap equivalent?

 

[cpm@]

Take a look at the hw.physmem parameter. For more details, see the loader(8)() man page.

 

[maneesh]

I have 3 GB system memory and I have set hw.physmem=2G.
sysctl -a shows:

hw.physmem: 2.12G
hw.usermem: 1.9G
hw.realmem: 2.15G

devinfo -rv shows:

ram0:
  0x00-0x9f3ff
  0x10000000-0xbfedffff
  0xbff00000-0xbfffffff

Here, looks like it is showing the full 3 GB mapping.

Now, how do I know which is that 1 GB available memory[]? Also, which function[](similar to ioremap) should I call to map the physical address to virtual address?

 

[cpm@]

As equivalent of linux's ioremap(), probably you want use the function pmap_mapdev(). Read http://lists.freebsd.org/pipermail/freebsd-hackers/2006-August/017606.html.

Please, to solve this kind of questions you can ask at the freebsd-hackers mailing list, where will help you gladly